ISL6265CHRTZ [RENESAS]

Multi-Output Controller with Integrated MOSFET Drivers for AMD SVI Capable Mobile CPUs;
ISL6265CHRTZ
型号: ISL6265CHRTZ
厂家: RENESAS TECHNOLOGY CORP    RENESAS TECHNOLOGY CORP
描述:

Multi-Output Controller with Integrated MOSFET Drivers for AMD SVI Capable Mobile CPUs

文件: 总27页 (文件大小:1226K)
中文:  中文翻译
下载:  下载PDF数据表文档文件
DATASHEET  
ISL6265C  
FN6976  
Rev 2.00  
January 11, 2013  
Multi-Output Controller with Integrated MOSFET Drivers for AMD SVI Capable  
Mobile CPUs  
The ISL6265C is a multi-output controller with embedded gate  
Features  
drivers. A single-phase controller powers the Northbridge  
• Core Configuration Flexibility  
(VDDNB) portion of the CPU. The two remaining controller  
channels can be configured for two-phase or individual  
single-phase outputs. For uniplane CPU applications, the  
ISL6265C is configured as a two-phase buck converter. This  
allows the controller to interleave channels to effectively double  
the output voltage ripple frequency, and thereby reduce output  
voltage ripple amplitude with fewer components, lower  
component cost, reduced power dissipation, and smaller area.  
For dual-plane processors, the ISL6265C can be configured as  
independent single-phase controllers powering VDD0 and  
VDD1.  
- Dual Plane, Single-Phase Controllers  
- Uniplane, Two-Phase Controller  
• Precision Voltage Regulators  
- 0.5% System Accuracy Over-temperature  
• Voltage Positioning with Adjustable Load Line and Offset  
• Internal Gate Drivers with 2A Driving Capability  
• Differential Remote CPU Die Voltage Sensing  
• Core Differential Current Sensing: DCR or Resistor  
• Northbridge Lossless rDS(ON) Current Sensing  
The heart of the ISL6265C is the patented R3 Technology™,  
Intersil’s Robust Ripple Regulator modulator. Compared with  
the traditional buck regulator, the R3 Technologyhas a faster  
transient response. This is due to the R3 modulator  
commanding variable switching frequency during a load  
transient.  
• Serial VID Interface  
- Two Wire Clock and Data Bus  
- Supports High-Speed I2C  
- 0.500V to 1.55V in 12.5mV Steps  
- Supports PSI_L Power-Saving Mode  
The Serial VID Interface (SVI) allows dynamic adjustment of  
the Core and Northbridge output voltages independently and in  
combination from 0.500V to 1.55V. Core and Northbridge  
output voltages achieve a 0.5% system accuracy  
over-temperature.  
• Core Outputs Feature Phase Shedding with PSI_L  
• Adjustable Output-Voltage Offset  
• Digital Soft-Start of all Outputs  
A unity-gain differential amplifier is provided for remote CPU  
die sensing. This allows the voltage on the CPU die to be  
accurately regulated per AMD mobile CPU specifications. Core  
output current sensing is realized using lossless inductor DCR  
sensing. All outputs feature overcurrent, overvoltage and  
undervoltage protection.  
• User Programmable Switching Frequency  
• Static and Dynamic Current Sharing (Uniplane Core)  
• Overvoltage, Undervoltage, and Overcurrent Protection  
• Pb-Free (RoHS compliant)  
Applications  
• AMD Griffin Platform CPU  
Related Literature  
• See FN6884 for “Multi-Output Controller with Integrated  
MOSFET Drivers for AMD SVI Capable Mobile CPUs”  
• Notebook Core/GPU Voltage Regulators  
POWER  
STAGE  
CORE_0  
CORE_1  
POWER  
STAGE  
ISL6265C  
POWER  
STAGE  
FIGURE 1. SIMPLIFIED SYSTEM DIAGRAM  
FN6976 Rev 2.00  
January 11, 2013  
Page 1 of 27  
ISL6265C  
Functional Block Diagram  
COMP_NB  
RTN_NB  
FB_NB  
FSET_NB  
VSEN_NB  
PVCC  
I
FSET_NB  
VNB  
BOOT_NB  
UGATE_NB  
PHASE_NB  
LGATE_NB  
1
3.0kΩ  
FLT  
1.5kΩ  
SVC  
SVD  
MOSFET  
DRIVER  
NO DROOP  
PSI_L  
MODULATOR  
NB  
E/A  
SHOOT-THRU  
PROTECTION  
I_OFS  
PWROK  
VREF_NB  
VREF0  
VREF_NB  
DE MODE  
PGND_NB  
VIN  
VREF1  
OFS/FIXEN  
PSI_L  
PVCC  
VCC  
POWER-ON  
ENABLE  
RESET AND  
SOFT-START  
LOGIC  
OCSET_NB  
OCSET  
RBIAS  
FLT  
VNB  
V0  
PGOOD  
GND  
FAULT  
PROTECTION  
RTN1  
V1  
ISEN0  
MODE  
ISEN1  
VIN  
VW0  
PVCC  
I
VW0  
COMP0  
FB0  
BOOT0  
UGATE0  
PHASE0  
LGATE0  
FLT  
E/A  
I_OFS  
MOSFET  
DRIVER  
VDIFF0  
VSEN0  
RTN0  
VREF0  
SHOOT-THRU  
PROTECTION  
VIN  
V0  
1
DE MODE  
PGND0  
NO  
DROOP  
MODE  
ISEN0  
ISEN1  
MODULATOR  
CORE  
PSI_L  
ISP0  
ISN0  
CURRENT  
SENSE  
PVCC  
FLT  
MODE  
NO  
CURRENT  
BALANCE  
BOOT1  
UGATE1  
PHASE1  
LGATE1  
ISP1  
ISN1  
CURRENT  
SENSE  
DROOP  
MOSFET  
DRIVER  
MODE  
V1  
VSEN1  
RTN1  
SHOOT-THRU  
PROTECTION  
1
VREF1  
DE MODE  
PGND1  
E/A  
VDIFF1  
I_OFS  
PSI_L  
I
VW1  
FB1  
COMP1  
VW1  
FIGURE 2. SIMPLIFIED FUNCTIONAL BLOCK DIAGRAM OF ISL6265C  
FN6976 Rev 2.00  
January 11, 2013  
Page 2 of 27  
ISL6265C  
Ordering Information  
PART  
MARKING  
TEMP RANGE  
(°C)  
PACKAGE  
(Pb-Free)  
PART NUMBER (Notes 2, 3)  
PKG. DWG. #  
L48.6x6  
ISL6265CHRTZ  
6265C HRTZ  
6265C HRTZ  
-10 to +100  
-10 to +100  
48 Ld 6x6 TQFN  
ISL6265CHRTZ-T (Note 1)  
48 Ld 6x6 TQFN  
Tape and Reel  
L48.6x6  
ISL6265CIRTZ  
6265C IRTZ  
6265C IRTZ  
-40 to +100  
-40 to +100  
48 Ld 6x6 TQFN  
L48.6x6  
L48.6x6  
ISL6265CIRTZ-T (Note 1)  
48 Ld 6x6 TQFN  
Tape and Reel  
NOTES:  
1. Please refer to TB347 for details on reel specifications.  
2. These Intersil Pb-free plastic packaged products employ special Pb-free material sets, molding compounds/die attach materials, and 100% matte  
tin plate plus anneal (e3 termination finish, which is RoHS compliant and compatible with both SnPb and Pb-free soldering operations). Intersil  
Pb-free products are MSL classified at Pb-free peak reflow temperatures that meet or exceed the Pb-free requirements of IPC/JEDEC J STD-020.  
3. For Moisture Sensitivity Level (MSL), please see device information page for ISL6265C. For more information on MSL please see techbrief TB363.  
Pin Configuration  
ISL6265C  
(48 LD TQFN)  
TOP VIEW  
48 47 46 45 44 43 42 41 40 39 38 37  
BOOT_NB  
BOOT0  
UGATE0  
PHASE0  
PGND0  
LGATE0  
PVCC  
OFS/VFIXEN  
PGOOD  
PWROK  
SVD  
1
2
3
4
5
6
7
8
9
36  
35  
34  
33  
32  
31  
30  
29  
28  
27  
26  
25  
SVC  
49  
GND  
[BOTTOM]  
ENABLE  
RBIAS  
LGATE1  
PGND1  
PHASE1  
UGATE1  
BOOT1  
OCSET  
VDIFF0  
FB0 10  
COMP0 11  
VW0 12  
13 14 15 16 17 18 19 20 21 22 23 24  
FN6976 Rev 2.00  
January 11, 2013  
Page 3 of 27  
ISL6265C  
Pin Descriptions  
PIN(s)  
SYMBOL(s)  
DESCRIPTION  
1
OFS/VFIXEN  
A resistor from this pin to GND programs a DC current source, which generates a positive offset voltage  
across the resistor between FB and VDIFF pins. In this case, the OFS pin voltage is +1.2V and VFIX mode  
is not enabled. If OFS is pulled up to +3.3V, VFIX mode is enabled, the DAC decodes the SVC and SVD  
inputs to determine the programmed voltage, and the OFS function is disabled. If OFS is pulled up to +5V,  
the OFS function and VFIX mode are disabled.  
2
3
PGOOD  
PWROK  
Controller power-good open-drain output. This pin is typically pulled up externally by a 2.0kΩ resistor to  
+3.3V. During normal operation, this pin indicates whether all output voltages are within specified  
overvoltage and undervoltage limits and no overcurrent condition is present. If any output voltage  
exceeds these limits or a reset event occurs, the pin is pulled low. This pin is always low prior to the end  
of soft-start.  
System power good input. When this pin is high, the SVI interface is active and I2C protocol is running.  
While this pin is low, the SVC, SVD, and VFIXEN input states determine the pre-PWROK metal VID or VFIX  
mode voltage. This pin must be low prior to the ISL6265C PGOOD output going high per the AMD SVI  
Controller Guidelines.  
4
5
6
7
SVD  
SVC  
This pin is the serial VID data bidirectional signal to and from the master device on the AMD processor.  
This pin is the serial VID clock input from the AMD processor.  
ENABLE  
RBIAS  
Digital input enable. A high level logic signal on this pin enables the ISL6265C.  
A 117kΩ resistor from RBIAS to GND sets internal reference currents. The addition of capacitance to this  
pin must be avoided and can create instabilities in operation.  
8
OCSET  
CORE_0 and CORE_1 common overcurrent protection selection input. The voltage on this pin sets the  
(ISPx - ISNx) voltage limit for OC trip.  
9, 19  
VDIFF0, VDIFF1  
FB0, FB1  
Output of the CORE_0 and CORE_1 differential amplifiers.  
10, 20  
These pins are the output voltage feedback to the inverting input of the CORE_0 and CORE_1 error  
amplifiers.  
11, 21  
12, 22  
COMP0, COMP1  
VW0, VW1  
The output of the CORE_0 and CORE_1 controller error amplifiers respectively. FBx, VDIFFx, and COMPx  
pins are tied together through external R-C networks to compensate the regulator  
A resistor from this pin to corresponding COMPx pin programs the switching frequency (for example,  
6.81k ~ 300kHz).  
13, 14, 23, 24  
ISP0, ISN0, ISP1, ISN1 These pins are used for differentially sensing the corresponding channel output current. The sensed  
current is used for channel balancing, protection, and core load line regulation.  
Connect ISN0 and ISN1 to the node between the RC sense elements surrounding the inductor of their  
respective channel. Tie the ISP0 and ISP1 pins to the VCORE side of their corresponding channel’s sense  
capacitor. These pins can also be used for discrete resistor sensing.  
15, 16  
18, 17  
VSEN0, RTN0  
VSEN1, RTN1  
Inputs to the CORE_0 VR controller precision differential remote sense amplifier. Connect to the sense  
pins of the VDD0_FB[H,L] portion of the processor.  
Inputs to the CORE_1 VR controller precision differential remote sense amplifier. Connect to the sense  
pins of the VDD1_FB[H,L] portion of the processor. The RTN1 pin is also used for detection of the  
VDD_PLANE_STRAP signal prior to enable.  
30  
PVCC  
The power supply pin for the internal MOSFET gate drivers of the ISL6265C. Connect this pin to a +5V  
power supply. Decouple this pin with a quality 1.0µF ceramic capacitor.  
31, 29  
32, 28  
LGATE0, LGATE1  
PGND0, PGND1  
Connect these pins to the corresponding lower MOSFET gate(s).  
The return path of the lower gate driver for CORE_0 and CORE_1 respectively. Connect these pins to the  
corresponding sources of the lower MOSFETs.  
33, 27  
34, 26  
35, 25  
PHASE0, PHASE1  
UGATE0, UGATE1  
BOOT0, BOOT1  
Switch node of the CORE_0 and CORE_1 controllers. Connect these pins to the sources of the  
corresponding upper MOSFET(s). These pins are the return path for the upper MOSFET drives.  
Connect these pins to the corresponding upper MOSFET gate(s). These pins control the upper MOSFET  
gate(s) and are monitored for shoot-through prevention.  
These pins provide the bias voltage for the corresponding upper MOSFET drives. Connect these pins to  
appropriately chosen external bootstrap capacitors. Internal bootstrap diodes connected to the PVCC pin  
provide the necessary bootstrap charge.  
FN6976 Rev 2.00  
January 11, 2013  
Page 4 of 27  
ISL6265C  
Pin Descriptions(Continued)  
PIN(s)  
SYMBOL(s)  
DESCRIPTION  
36  
BOOT_NB  
This pin is the upper gate drive supply voltage for the Northbridge controller. Connect an appropriately  
sized ceramic bootstrap capacitor between the BOOT_NB and PHASE_NB pins. An internal bootstrap  
diode connected to the PVCC pin provides the necessary bootstrap charge.  
37  
38  
UGATE_NB  
PHASE_NB  
Upper MOSFET gate signal from Northbridge controller.  
Switch node of the Northbridge controller. This pin should connect to the source of the Northbridge  
channel upper MOSFET(s).  
39  
40  
LGATE_NB  
PGND_NB  
Lower MOSFET gate signal from Northbridge controller.  
The return path of the Northbridge controller lower gate driver. Connect this pin to the source of the lower  
MOSFET(s).  
41  
43, 42  
44  
OCSET_NB  
VSEN_NB, RTN_NB  
FSET_NB  
Overcurrent protection selection input for the Northbridge controller. A resistor from this pin to  
PHASE_NB sets the OC trip point.  
Remote Northbridge voltage sense input and return. Connect isolated traces from these pins to the  
Northbridge sense points of the processor.  
A resistor from this pin to GND programs the switching frequency of the Northbridge controller (for  
example, 22.1k ~ 260kHz).  
45  
46  
47  
COMP_NB  
FB_NB  
VCC  
This pin is the output of the Northbridge controller error amplifier.  
This pin is the output voltage feedback to the inverting input of the Northbridge controller error amplifier.  
The bias supply for the IC’s control circuitry. Connect this pin to a +5V supply and decouple using a quality  
0.1µF ceramic capacitor.  
48  
-
VIN  
Battery supply voltage. It is used for input voltage feed-forward to improve the input line transient  
performance.  
GND  
The bias and reference ground for the IC. The GND connection for the ISL6265C is through the thermal  
pad on the bottom of the package.  
FN6976 Rev 2.00  
January 11, 2013  
Page 5 of 27  
ISL6265C  
Simplified Application Circuit for Dual Plane and Northbridge Support  
VIN  
+5V  
VIN  
VCC  
PVCC  
GND  
+VIN  
SVI DATA  
SVI CLOCK  
ENABLE  
SVD  
C
IN  
SVC  
EN  
UGATE0  
PWROK  
PWROK  
PGOOD  
BOOT0  
PHASE0  
LGATE0  
L
OUT  
VDD0  
VDDPWRGD  
VSEN0  
RTN0  
REMOTE  
SENSE  
CORE  
LOAD  
PGND0  
ISP0  
VSEN1  
RTN1  
REMOTE  
SENSE  
ISN0  
VDD_PLANE_STRAP  
RBIAS  
OFS/VFIXEN  
VDIFF0  
OCSET  
+VIN  
C
IN  
FB0  
UGATE1  
BOOT1  
ISL6265C  
COMP0  
L
OUT  
VDD1  
PHASE1  
LGATE1  
VW0  
CORE  
LOAD  
PGND1  
ISP1  
VDIFF1  
ISN1  
+VIN  
FB1  
C
IN  
COMP1  
UGATE_NB  
BOOT_NB  
PHASE_NB  
LGATE_NB  
PGND_NB  
L
OUT  
VDDNB  
VW1  
FSET_NB  
NB  
LOAD  
COMP_NB  
FB_NB  
OCSET_NB  
VSEN_NB  
RTN_NB  
FIGURE 3. ISL6265C BASED DUAL-PLANE AND NORTHBRIDGE CONVERTERS WITH INDUCTOR DCR CURRENT SENSING  
FN6976 Rev 2.00  
January 11, 2013  
Page 6 of 27  
ISL6265C  
Simplified Application Circuit for Uniplane Core and Northbridge Support  
VIN  
+5V  
+VIN  
VCC  
PVCC  
GND  
C
L
IN  
SVI DATA  
SVI CLOCK  
ENABLE  
SVD  
UGATE0  
SVC  
EN  
BOOT0  
PHASE0  
LGATE0  
OUT  
PWROK  
PWROK  
PGOOD  
VDDPWRGD  
CORE  
LOAD  
PGND0  
ISP0  
VSEN0  
RTN0  
REMOTE  
SENSE  
ISN0  
REMOTE  
SENSE  
VSEN1  
RTN1  
VDD_PLANE_STRAP  
RBIAS  
OCSET  
VDD0  
OFS/VFIXEN  
VDIFF0  
+VIN  
C
IN  
UGATE1  
BOOT1  
FB0  
L
OUT  
ISL6265C  
COMP0  
PHASE1  
LGATE1  
CORE  
LOAD  
PGND1  
ISP1  
VW0  
VDIFF1  
OPEN  
ISN1  
+VIN  
OPEN  
OPEN  
FB1  
C
IN  
COMP1  
UGATE_NB  
BOOT_NB  
PHASE_NB  
LGATE_NB  
PGND_NB  
L
OUT  
VDDNB  
OPEN VW1  
FSET_NB  
NB  
LOAD  
OCSET_NB  
VSEN_NB  
RTN_NB  
COMP_NB  
FB_NB  
FIGURE 4. ISL6265C BASED UNIPLANE AND NORTHBRIDGE CONVERTERS WITH INDUCTOR DCR CURRENT SENSING  
FN6976 Rev 2.00  
January 11, 2013  
Page 7 of 27  
ISL6265C  
Simplified Application Circuit for Dual Layout  
VIN  
+5V  
+VIN  
VCC PVCC  
GND  
C
L
IN  
SVI DATA  
SVI CLOCK  
ENABLE  
SVD  
UGATE0  
SVC  
EN  
BOOT0  
PHASE0  
LGATE0  
OUT  
PWROK  
PGOOD  
PWROK  
VDD0  
VDDPWRGD  
CORE  
LOAD  
PGND0  
ISP0  
VSEN0  
RTN0  
REMOTE  
SENSE  
VDD_PLANE_STRAP  
+1.8V  
ISN0  
RTN1  
REMOTE  
SENSE  
DNP UNIPLANE  
VSEN1  
RBIAS  
DNP  
UNIPLANE  
VDD0  
DUAL  
OCSET  
PLANE  
OFS/VFIXEN  
VDIFF0  
+VIN  
C
IN  
UGATE1  
BOOT1  
FB0  
L
OUT  
ISL6265C  
COMP0  
PHASE1  
LGATE1  
VDD1  
CORE  
LOAD  
PGND1  
ISP1  
VW0  
VDIFF1  
ISN1  
+VIN  
FB1  
C
IN  
COMP1  
UGATE_NB  
BOOT_NB  
PHASE_NB  
LGATE_NB  
PGND_NB  
L
OUT  
VDDNB  
VW1  
FSET_NB  
NB  
LOAD  
OCSET_NB  
VSEN_NB  
RTN_NB  
COMP_NB  
FB_NB  
FIGURE 5. ISL6265C BASED UNIPLANE OR DUAL PLANE CORE CONVERTER WITH INDUCTOR DCR CURRENT SENSING  
FN6976 Rev 2.00  
January 11, 2013  
Page 8 of 27  
ISL6265C  
Table of Contents  
Absolute Maximum Ratings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10  
Thermal Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10  
Recommended Operating Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10  
Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10  
ISL6265C Gate Driver Timing Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13  
Theory of Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14  
Modulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14  
Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14  
Power-On Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15  
Core Configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15  
Mode Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15  
Serial VID Interface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15  
Pre-PWROK Metal VID. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16  
VFIX MODE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16  
SVI MODE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16  
VID-On-the-Fly Transition. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16  
SVI WIRE Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16  
SVI Bus Protocol. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18  
Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18  
Switching Frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18  
Current Sense. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19  
Selecting RBIAS For Core Outputs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20  
Offset Resistor Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20  
Internal Driver Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20  
MOSFET Gate-Drive Outputs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20  
Diode Emulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20  
Power-Savings Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20  
Northbridge and Dual Plane Core . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20  
Uniplane Core. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21  
Fault Monitoring and Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21  
Power-Good Signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21  
Overcurrent Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21  
Overvoltage Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22  
Undervoltage Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22  
General Application Design Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22  
Selecting the LC Output Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22  
Selection of the Input Capacitor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23  
MOSFET Selection and Considerations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23  
Selecting The Bootstrap Capacitor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24  
PCB Layout Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24  
Power and Signal Layers Placement on the PCB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24  
Component Placement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24  
Signal Ground and Power Ground . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24  
Routing and Connection Details . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24  
Copper Size for the Phase Node . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25  
Revision History. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26  
About Intersil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26  
Package Outline Drawing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27  
FN6976 Rev 2.00  
January 11, 2013  
Page 9 of 27  
ISL6265C  
P
Absolute Maximum Ratings  
Thermal Information  
Supply Voltage, VCC, PVCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3 - +7V  
Battery Voltage, VIN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +28V  
Boot Voltage (BOOT). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to +33V  
Boot to Phase Voltage (BOOT-PHASE) . . . . . . . . . . . . . . . . -0.3V to +7V(DC)  
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .-0.3V to +9V (<10ns)  
Phase Voltage (PHASE) . . . . . . . . . . . . . . . . -7V (<20ns Pulse Width, 10µJ)  
UGATE Voltage (UGATE) . . . . . . . . . . . . . . . . . . . PHASE -0.3V (DC) to BOOT  
LGATE Voltage (LGATE) . . . . . . . . . . . . . . . . . . . . . -0.3V (DC) to VCC + 0.3V  
ALL Other Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .-0.3V to (VCC + 0.3V)  
Open Drain Outputs, PGOOD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3 - +7V  
Thermal Resistance (Typical)  
TQFN Package (Notes 4, 5) . . . . . . . . . . . . .  
Maximum Junction Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . .+150°C  
Maximum Storage Temperature Range . . . . . . . . . . . . . .-65°C to +150°C  
Pb-Free Reflow Profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . see link below  
http://www.intersil.com/pbfree/Pb-FreeReflow.asp  
JA (°C/W)  
28  
JC (°C/W)  
3.5  
Recommended Operating Conditions  
Supply Voltage, VCC, PVCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .+5V ±5%  
Battery Voltage, VIN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +6V to 24V  
Ambient Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . .-40°C to +100°C  
Junction Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . .-40°C to +125°C  
CAUTION: Do not operate at or near the maximum ratings listed for extended periods of time. Exposure to such conditions may adversely impact product  
reliability and result in failures not covered by warranty.  
NOTES:  
4. JA is measured in free air with the component mounted on a high effective thermal conductivity test board with “direct attach” features. See Tech  
Brief TB379.  
5. For JC, the “case temp” location is the center of the exposed metal pad on the package underside.  
Electrical Specifications VCC = PVCC = 5V, VIN = 12V, TA = -10°C to +100°C (ISL6265HRTZ), TA = -40°C to +100°C (ISL6265IRTZ),  
unless otherwise specified. Boldface limits apply across the operating temperature range, -40°C to +100°C.  
MIN  
MAX  
PARAMETER  
INPUT POWER SUPPLY  
+5V Supply Current  
SYMBOL  
IVCC  
TEST CONDITIONS  
(Note 6)  
TYP  
(Note 6)  
UNITS  
EN = 3.3V  
EN = 0V  
-
7.8  
10  
1
mA  
µA  
V
-
-
4.35  
4.1  
-
POR (Power-On Reset) Threshold  
VCC PORr  
VCC PORf  
IVIN  
VCC Rising  
VCC Falling  
-
3.9  
-
4.5  
-
V
Battery Supply Current (VIN)  
SYSTEM AND REFERENCES  
System Accuracy  
EN = 0V, VIN = 24V  
1
µA  
HRTZ  
No load, closed loop, active mode  
VID = 0.75V to 1.55V  
-0.5  
-
0.5  
%
(Vcore0, Vcore1, Vcore_NB  
)
%Error  
VID = 0.50V to 0.7375V  
-5  
-
-
+5  
mV  
%
(VCORE  
)
IRTZ  
No load, closed loop, active mode  
VID = 0.75V to 1.55V  
-0.8  
0.8  
%Error  
VID = 0.50V to 0.7375V  
-8  
-
+8  
mV  
V
(VCORE  
)
RBIAS Voltage  
HRTZ  
RRBIAS = 117kΩ  
1.15  
1.17  
1.19  
RRBIAS  
IRTZ  
RRBIAS  
RRBIAS = 117kΩ  
1.14  
1.17  
1.55  
1.20  
V
V
V
Maximum Output Voltage  
Minimum Output Voltage  
VCOREx  
(max)  
SVID = [000_0000b]  
SVID = [101_0100b]  
-
-
-
-
VCOREx  
(min)  
0.500  
FN6976 Rev 2.00  
January 11, 2013  
Page 10 of 27  
ISL6265C  
Electrical Specifications VCC = PVCC = 5V, VIN = 12V, TA = -10°C to +100°C (ISL6265HRTZ), TA = -40°C to +100°C (ISL6265IRTZ),  
unless otherwise specified. Boldface limits apply across the operating temperature range, -40°C to +100°C. (Continued)  
MIN  
MAX  
PARAMETER  
SYMBOL  
TEST CONDITIONS  
(Note 6)  
TYP  
300  
(Note 6)  
UNITS  
kHz  
CHANNEL FREQUENCY  
Nominal CORE Switching Frequency  
HRTZ  
fSW_core0  
VIN = 15.5V, VDAC = 1.55V, VFB0 = 1.60V,  
force Vcomp_0 = 2V, RVW = 6.81kΩ, 2-Phase  
Operation  
285  
315  
IRTZ  
fSW_core0  
VIN = 15.5V, VDAC = 1.55V, VFB0 = 1.60V,  
force Vcomp_0 = 2V, RVW = 6.81kΩ, 2-Phase  
Operation  
280  
300  
320  
kHz  
Nominal NB Switching Frequency  
HRTZ  
fSW_core_NB  
RFSET_NB = 22.1kΩ, CFSET_NB = 1nF,  
285  
300  
300  
315  
kHz  
kHz  
V
DAC = 0.5V, Vsen_nb = 0.51V  
RFSET_NB = 22.1kΩ, CFSET_NB = 1nF,  
DAC = 0.5V, Vsen_nb = 0.51V  
IRTZ  
fSW_core_NB  
280  
320  
V
Core Frequency Adjustment Range  
NB Frequency Adjustment Range  
AMPLIFIERS  
200  
200  
-
-
500  
500  
kHz  
kHz  
Error Amp DC Gain (Note 7)  
AV0  
-
-
90  
18  
-
-
dB  
Error Amp Gain-Bandwidth Product  
(Note 7)  
GBW  
CL = 20pF  
CL = 20pF  
MHz  
Error Amp Slew Rate (Note 7)  
CORE CURRENT SENSE  
Current Imbalance Threshold  
Input Bias Current  
SR  
-
5.0  
-
V/µs  
-
-
-
4
-
-
-
mV  
nA  
V
20  
0.8  
RTN1 Threshold  
SOFT START/VID-ON-THE-FLY  
Soft-Start Voltage Transition  
VID on the Fly Transition  
VSS  
1.25  
5
1.875  
7.5  
2.50  
10  
mV/µs  
mV/µs  
GATE DRIVER DRIVING CAPABILITY [CORE AND NB]  
UGATE Source Resistance (Note 8)  
UGATE Source Current (Note 8)  
UGATE Sink Resistance (Note 8)  
UGATE Sink Current (Note 8)  
LGATE Source Resistance (Note 8)  
LGATE Source Current (Note 8)  
LGATE Sink Resistance (Note 8)  
LGATE Sink Current (Note 8)  
UGATE to PHASE Resistance  
RSRC(UGATE) 500mA Source Current  
ISRC(UGATE) VUGATE_PHASE = 2.5V  
RSNK(UGATE) 500mA Sink Current  
ISNK(UGATE) VUGATE_PHASE = 2.5V  
RSRC(LGATE) 500mA Source Current  
ISRC(LGATE) VLGATE = 2.5V  
RSNK(LGATE) 500mA Sink Current  
ISNK(LGATE) VLGATE = 2.5V  
Rp(UGATE)  
-
-
-
-
-
-
-
-
-
1
2
1.5  
Ω
A
-
1
1.5  
Ω
A
2
-
1
1.5  
Ω
A
2
-
0.5  
4
0.9  
Ω
A
-
-
1
kΩ  
GATE DRIVER SWITCHING TIMING (Refer to “ISL6265C Gate Driver Timing Diagram” on page 13)  
UGATE Rise Time (Note 7)  
LGATE Rise Time (Note 7)  
UGATE Fall Time (Note 7)  
tRU  
tRL  
PVCC = 5V, 3nF Load  
-
-
-
-
-
-
8.0  
8.0  
8.0  
4.0  
36  
-
-
-
-
-
-
ns  
ns  
ns  
ns  
ns  
ns  
PVCC = 5V, 3nF Load  
tFU  
PVCC = 5V, 3nF Load  
LGATE Fall Time (Note 7)  
tFL  
PVCC = 5V, 3nF Load  
UGATE Turn-on Propagation Delay  
LGATE Turn-on Propagation Delay  
tPDHU  
tPDHL  
PVCC = 5V, Outputs Unloaded  
PVCC = 5V, Outputs Unloaded  
20  
FN6976 Rev 2.00  
January 11, 2013  
Page 11 of 27  
ISL6265C  
Electrical Specifications VCC = PVCC = 5V, VIN = 12V, TA = -10°C to +100°C (ISL6265HRTZ), TA = -40°C to +100°C (ISL6265IRTZ),  
unless otherwise specified. Boldface limits apply across the operating temperature range, -40°C to +100°C. (Continued)  
MIN  
MAX  
PARAMETER  
BOOTSTRAP DIODE  
SYMBOL  
TEST CONDITIONS  
(Note 6)  
TYP  
(Note 6)  
UNITS  
Forward Voltage  
HRTZ  
IRTZ  
VDDP = 5V, Forward Bias Current = 2mA  
VDDP = 5V, Forward Bias Current = 2mA  
VR = 16V  
0.43  
0.43  
-
0.58  
0.58  
-
0.67  
0.70  
5
V
V
Leakage  
µA  
POWER-GOOD AND PROTECTION MONITOR  
PGOOD Low Voltage  
VOL  
IPGOOD = 4mA  
-
0.2  
-
0.5  
1
V
PGOOD Leakage Current  
PGOOD High After Soft-Start  
PGOOD Low After Fault  
Undervoltage Threshold  
IOH  
PGOOD = 5V  
-1  
µA  
µs  
µs  
mV  
Enable to PGOOD High, VCOREx = 1.1V  
Fault to PGOOD Low  
570  
160  
240  
700  
208  
295  
1010  
250  
350  
HRTZ  
UVH  
VCOREx falls below set-point for 208µs  
IRTZ  
UVH  
VCOREx falls below set-point for 208µs  
VO rising above threshold > 0.5µs  
230  
295  
350  
mV  
V
Overvoltage Threshold  
OVHS  
1.770  
1.800  
1.825  
OVERCURRENT PROTECTION VDD0 AND VDD1  
OCSET Reference Voltage  
VOCSET = 180mV; VIN = 15.5V  
5
6.0  
7
mV  
(VISPx - VISNx  
)
OVERCURRENT PROTECTION VDD_NB  
OCSET_NB OCP Current  
HRTZ  
IRTZ  
RBIAS pin to GND = 117kΩ; Trips after 8 PWM  
cycles  
9.2  
10  
10  
10.8  
µA  
µA  
RBIAS pin to GND = 117kΩ; Trips after 8 PWM  
9.2  
10.9  
cycles  
OFFSET FUNCTION  
OFS Pin Voltage For Droop Enabling  
HRTZ  
VOFS  
ROFS = 240kΩ (OFS pin to GND)  
ROFS = 240kΩ (OFS pin to GND)  
IOFS = =10µA  
1.18  
1.2  
1.2  
1.22  
V
V
IRTZ  
VOFS  
1.17  
1.23  
FB Pin Source Current  
IFB  
9.0  
9.9  
1.8  
10.8  
µA  
V
OFS Pin Voltage Threshold for VFIX  
Mode and No Droop Operation  
VOFS  
-
-
OFS Pin Voltage Threshold for SVI  
Mode and No Droop Operation  
VOFS  
IOFS  
-
-
4.0  
4.0  
-
-
V
OFS Bias  
1.8V < OFS < VCC  
µA  
LOGIC INPUTS  
ENABLE Low Threshold  
ENABLE High Threshold  
ENABLE Leakage Current  
VIL(3.3V)  
VIH(3.3V)  
-
2.0  
-1  
-
1.35  
1.6  
0
0.9  
V
V
-
-
Logic input is low  
µA  
µA  
Logic input is high at 3.3V  
0
1
SVI INTERFACE  
PWROK Input Low Threshold  
PWROK Input High Threshold  
SVC, SVD Input HIGH (VIH)  
SVC, SVD Input LOW (VIL)  
Schmitt Trigger Input Hysteresis  
-
0.65  
0.9  
0.8  
V
V
V
V
V
-
-
1.05  
0.87  
0.68  
0.19  
-
0.45  
-
-
-
FN6976 Rev 2.00  
January 11, 2013  
Page 12 of 27  
ISL6265C  
Electrical Specifications VCC = PVCC = 5V, VIN = 12V, TA = -10°C to +100°C (ISL6265HRTZ), TA = -40°C to +100°C (ISL6265IRTZ),  
unless otherwise specified. Boldface limits apply across the operating temperature range, -40°C to +100°C. (Continued)  
MIN  
MAX  
PARAMETER  
SVD Low Level Output Voltage  
SVC, SVD Leakage  
SYMBOL  
TEST CONDITIONS  
3mA Sink Current  
(Note 6)  
TYP  
0.1  
(Note 6)  
UNITS  
V
-
-
-
0.285  
EN = 0V, SVC, SVD = 0V  
EN = 5V, SVC, SVD = 1.8V  
< -100  
< -100  
-
-
nA  
nA  
DIFF AMP  
Accuracy  
HRTZ  
IRTZ  
VSEN = 0.5V to 1.55V; RTN = 0 ±0.1V  
VSEN = 0.5V to 1.55V; RTN = 0 ±0.1V  
-2  
-
-
2
mV  
mV  
-2.5  
2.5  
NOTES:  
6. Parameters with MIN and/or MAX limits are 100% tested at +25°C, unless otherwise specified. Temperature limits established by characterization  
and are not production tested  
7. Limits should be considered typical and are not production tested.  
8. Limits established by characterization and are not production tested.  
ISL6265C Gate Driver Timing Diagram  
PWM  
t
PDHU  
t
FU  
t
RU  
1V  
UGATE  
LGATE  
1V  
t
t
FL  
RL  
t
PDHL  
FN6976 Rev 2.00  
January 11, 2013  
Page 13 of 27  
ISL6265C  
A window voltage VW is referenced with respect to the error  
amplifier output voltage VCOMP, creating an envelope into which  
the ripple voltage VR is compared. The amplitude of VW is set by a  
resistor connected across the FSET and GND pins. The VR, VCOMP,  
and VW signals feed into a window comparator in which VCOMP is  
the lower threshold voltage and VW is the higher threshold  
voltage. Figure 7 shows PWM pulses being generated as VR  
traverses the VW and VCOMP thresholds. The PWM switching  
frequency is proportional to the slew rates of the positive and  
negative slopes of VR; it is inversely proportional to the voltage  
Theory of Operation  
The ISL6265C is a flexible multi-output controller supporting  
Northbridge and single or dual power planes required by Class M  
AMD Mobile CPUs. In single plane applications, both core voltage  
regulators operate single-phase. In uniplane core applications,  
the core voltage regulators are configured to operate as a  
two-phase regulator. All three regulator outputs include  
integrated gate drivers for reduced system cost and small board  
area. The regulators provide optimum steady-state and transient  
performance for microprocessor applications. System efficiency  
is enhanced by idling a phase in uniplane configurations at low-  
current and implementing automatic DCM-mode operation when  
PSI_L is asserted to logic low.  
between VW and VCOMP  
.
VIN  
The heart of the ISL6265C is the R3 Technology™, Intersil's  
Robust Ripple Regulator modulator. The R3 modulator combines  
the best features of fixed frequency PWM and hysteretic PWM  
while eliminating many of their shortcomings. The ISL6265C  
modulator internally synthesizes an analog of the inductor ripple  
current and uses hysteretic comparators on those signals to  
establish PWM pulse widths. Operating on these large-  
amplitude, noise-free synthesized signals allows the ISL6265C to  
achieve lower output ripple and lower phase jitter than either  
conventional hysteretic or fixed frequency PWM controllers.  
Unlike conventional hysteretic converters, the ISL6265C has an  
error amplifier that allows the controller to maintain a 0.5%  
voltage regulation accuracy throughout the VID range from 0.75V  
to 1.55V. Voltage regulation accuracy is slightly wider, ±5mV,  
over the VID range from 0.7375V to 0.5V.  
PWM FREQUENCY  
CONTROL  
FSET  
-
+
g
+
V
V
m
IN  
W
-
-
+
R
Q
S
PWM  
V
VO  
R
-
+
g V  
-
m
O
V
COMP  
+
-
+
C
R TO  
PWM  
CONTROL  
ISL6265C  
FIGURE 6. MODULATOR CIRCUITRY  
The hysteresis window voltage is relative to the error amplifier  
output such that load current transients result in increased  
switching frequency, which gives the R3 regulator a faster  
response than conventional fixed frequency PWM controllers. In  
uniplane configurations, transient load current is inherently  
shared between active phases due to the use of a common  
hysteretic window voltage. Individual average phase currents are  
monitored and controlled to equally share current among the  
active phases.  
RIPPLE CAPACITOR VOLTAGE C  
WINDOW VOLTAGE V  
W
R
ERROR AMPLIFIER VOLTAGE V  
COMP  
Modulator  
PWM  
The ISL6265C modulator features Intersil’s R3 technology, a  
hybrid of fixed frequency PWM control and variable frequency  
hysteretic control (see Figure 6). Intersil’s R3 technology can  
simultaneously affect the PWM switching frequency and PWM  
duty cycle in response to input voltage and output load  
transients. The R3 modulator synthesizes an AC signal VR, which  
is an analog representation of the output inductor ripple current.  
The duty-cycle of VR is the result of charge and discharge current  
through a ripple capacitor CR. The current through CR is provided  
by a transconductance amplifier gm that measures the VIN and  
VO voltages. The positive slope of VR can be written as  
determined by Equation 1:  
FIGURE 7. MODULATOR WAVEFORMS DURING LOAD TRANSIENT  
Initialization  
Once sufficient bias is applied to the VCC pin, internal logic  
checks the status of critical pins to determine the controller  
operation profile prior to ENABLE. These pins include RTN1 which  
determines single vs two-phase operation and OFS/VFIXEN for  
enabling/disabling the SVI interface and core voltage droop.  
Depending on the configuration set by these pins, the controller  
then checks the state of the SVC and SVD pins to determine the  
soft-start target output voltage level.  
(EQ. 1)  
V
= g   V V  
OUT  
RPOS  
m
IN  
The negative slope of VR can be written as determined by  
Equation 2:  
(EQ. 2)  
V
= g V  
m OUT  
RNEG  
Where gm is the gain of the transconductance amplifier.  
FN6976 Rev 2.00  
January 11, 2013  
Page 14 of 27  
ISL6265C  
Power-On Reset  
Mode Selection  
The ISL6265C requires a +5V input supply tied to VCC and PVCC  
to exceed a rising power-on reset (POR) threshold before the  
controller has sufficient bias to guarantee proper operation. Once  
this threshold is reached or exceeded, the ISL6265C has enough  
bias to begin checking RTN1, OFS/VFIXEN, ENABLE, and SVI  
inputs. Hysteresis between the rising the falling thresholds  
assure the ISL6265C will not inadvertently turn-off unless the  
bias voltage drops substantially (see “Electrical Specifications”  
on page 12).  
The OFS/VFIXEN pin selects between the AMD defined VFIX and  
SVI modes of operation and enables droop if desired in SVI mode  
only. If OFS/VFIXEN is tied to VCC, then SVI mode with no droop  
on the core output(s) is selected. Connected to +3.3V, VFIX mode  
is active with no droop on the core output(s). SVI mode with  
droop is enabled when OFS/VFIXEN is tied to ground through a  
resistor sized to set the core voltage positive offset. Further  
information is provided in “Offset Resistor Selection” on page 20.  
Serial VID Interface  
Core Configuration  
The on-board Serial VID Interface (SVI) circuitry allows the  
processor to directly control the Core and Northbridge voltage  
reference levels within the ISL6265C. The SVC and SVD states  
are decoded according to the PWROK and VFIXEN inputs as  
described in the following sections. The ISL6265C uses a  
digital-to-analog converter (DAC) to generate a reference voltage  
based on the decoded SVI value. See Figure 8 for a simple SVI  
interface timing diagram.  
The ISL6265C determines the core channel requirements of the  
CPU based on the state of the RTN1 pin prior to ENABLE. If RTN1  
is low prior to ENABLE, both VDD0 and VDD1 core planes are  
required. The core controllers operate as independent  
single-phase regulators. RTN1 is connected to the CPU Core1  
negative sense point. For single core CPU designs (uniplane),  
RTN1 is tied to a +1.8V or greater supply. Prior to ENABLE, RTN1  
is detected as HIGH and the ISL6265C drives the core controllers  
as a two-phase multi-phase regulator. Dual purpose motherboard  
designs should include resistor options to open the CPU Core1  
negative sense and connect the RTN1 pin to a pull-up resistor.  
1
4
5
6
2
3
7
8
9
10  
11  
12  
VCC  
SVC  
SVD  
ENABLE  
PWROK  
V_SVI  
V_SVI  
METAL_VID  
METAL_VID  
VDD AND VDDNB  
VDDPWRGD  
(PGOOD)  
FIXEN  
Interval 1 to 2: ISL6265C waits to POR.  
Interval 2 to 3: SVC and SVD are externally set to pre-Metal VID code.  
Interval 3 to 4: EN locks core output configuration and pre-Metal VID code. All outputs soft-start to this level.  
Interval 4 to 5: PGOOD signal goes HIGH indicating proper operation.  
Interval 5 to 6: CPU detects VDDPWRGD high and drives PWROK high to allow ISL6265C to prepare for SVI code.  
Interval 6 to 7: SVC and SVD data lines communicate change in VID code.  
Interval 7 to 8: ISL6265C responds to VID-ON-THE-FLY code change.  
Interval 8 to 9: PWROK is driven low and ISL6265C returns all outputs to pre-PWROK Metal VID level.  
Interval 9 to 10: PWROK driven high once again by CPU and ISL6265C prepares for SVI code.  
Interval 10 to 11: SVC and SVD data lines communicate new VID code.  
Interval 11 to 12: ISL6265C drives outputs to new VID code level.  
Post 12 : Enable falls and all internal drivers are tri-stated and PGOOD is driven low.  
FIGURE 8. SVI INTERFACE TIMING DIAGRAM: TYPICAL PRE-PWROK METAL VID STARTUP  
FN6976 Rev 2.00  
January 11, 2013  
Page 15 of 27  
ISL6265C  
Pre-PWROK Metal VID  
SVI MODE  
Assuming the OFS/VFIXEN pin is not tied to +3.3V during  
controller configuration, typical motherboard start-up begins with  
the controller decoding the SVC and SVD inputs to determine the  
pre-PWROK metal VID setting (see Table 1). Once the enable  
input (EN) exceeds the rising enable threshold, the ISL6265C  
decodes and locks the decoded value in an on-board hold  
register.  
Once the controller has successfully soft-started and PGOOD  
transitions high, the processor can assert PWROK to signal the  
ISL6265C to prepare for SVI commands. The controller actively  
monitors the SVI interface for set VID commands to move the  
plane voltages to start-up VID values. Details of the SVI Bus  
protocol are provided in the AMD Design Guide for Voltage  
Regulator Controllers Accepting Serial VID Codes specification.  
The internal DAC circuitry begins to ramp Core and Northbridge  
planes to the decoded pre-PWROK metal VID output level. The  
digital soft-start circuitry ramps the internal reference to the  
target gradually at a fixed rate of approximately 2mV/µs. The  
controlled ramp of all output voltage planes reduces in-rush  
current during the soft-start interval. At the end of the soft-start  
interval, the PGOOD output transitions high indicating all output  
planes are within regulation limits.  
Once a set VID command is received, the ISL6265C decodes the  
information to determine which output plane is affected and the  
VID target required (see Table 3).The internal DAC circuitry steps  
the required output plane voltage to the new VID level. During  
this time, one or more of the planes could be targeted. In the  
event either core voltage plane, VDD0 or VDD1, is commanded to  
power-off by serial VID commands, the PGOOD signal remains  
asserted. The Northbridge voltage plane must remain active  
during this time.  
TABLE 1. PRE-PWROK METAL VID CODES  
If the PWROK input is de-asserted, then the controller steps both  
Core and Northbridge planes back to the stored pre-PWROK  
metal VID level in the holding register from initial soft-start. No  
attempt is made to read the SVC and SVD inputs during this time.  
If PWROK is reasserted, then the on-board SVI interface waits for  
a set VID command.  
SVC  
0
SVD  
0
OUTPUT VOLTAGE (V)  
1.1  
1.0  
0.9  
0.8  
0
1
1
0
1
1
If EN goes low during normal operation, all internal drivers are  
tri-stated and PGOOD is pulled low. This event clears the  
pre-PWROK metal VID code and forces the controller to check  
SVC and SVD upon restart.  
If the EN input falls below the enable falling threshold, the  
ISL6265C tri-states all outputs. PGOOD is pulled low with the loss  
of EN. The Core and Northbridge planes will decay based on  
output capacitance and load leakage resistance. If bias to VCC  
falls below the POR level, the ISL6265C responds in the same  
manner previously described. Once VCC and EN rise above their  
respective rising thresholds, the internal DAC circuitry re-acquires  
a pre-PWROK metal VID code and the controller soft-starts.  
A POR event on VCC during normal operation will shutdown all  
regulators and PGOOD is pulled low. The pre-PWROK metal VID  
code is not retained.  
VID-On-the-Fly Transition  
Once PWROK is high, the ISL6265C detects this flag and begins  
monitoring the SVC and SVD pins for SVI instructions. The  
microprocessor will follow the protocol outlined in the following  
sections to send instructions for VID-on-the-Fly transitions. The  
ISL6265C decodes the instruction and acknowledges the new  
VID code. For VID codes higher than the current VID level, the  
ISL6265C begins stepping the required regulator output(s) to the  
new VID target with a typical slew rate of 7.5mV/µs, which meets  
the AMD requirements.  
VFIX MODE  
In VFIX Mode, the SVC and SVD levels fixed external to the  
controller through jumpers to either GND or VDDIO. These inputs  
are not expected to change. In VFIX mode, the IC decodes the  
SVC and SVD states per Table 2.  
TABLE 2. VFIXEN VID CODES  
SVC  
0
SVD  
0
OUTPUT VOLTAGE (V)  
When the VID codes are lower than the current VID level, the  
ISL6265C begins stepping the regulator output to the new VID  
target with a typical slew rate of -7.5mV/µs. Both Core and NB  
regulators are always in CCM during a down VID transition. The  
AMD requirements under these conditions do not require the  
regulator to meet the minimum slew rate specification of  
-5mV/µs. In either case, the slew rate is not allowed to exceed  
10mV/µs. The ISL6265C does not change the state of PGOOD  
(VDDPWRGD in AMD specifications) when a VID-on-the-fly  
transition occurs.  
1.4  
1.2  
1.0  
0.8  
0
1
1
0
1
1
Once enabled, the ISL6265C begins to soft-start both Core and  
Northbridge planes to the programmed VFIX level. The internal  
soft-start circuitry slowly ramps the reference up to the target  
value. The same fixed internal rate of approximately 2mV/µs  
results in a controlled ramp of the power planes. Once soft-start  
has ended and all output planes are within regulation limits, the  
PGOOD pin transitions high.  
SVI WIRE Protocol  
The SVI wire protocol is based on the I2C bus concept. Two wires  
(serial clock (SVC) and serial data (SVD)), carry information  
between the AMD processor (master) and VR controller (slave) on  
the bus. The master initiates and terminates SVI transactions  
In the same manner described in “Pre-PWROK Metal VID” on  
page 16, the POR circuitry impacts the internal driver operation  
and PGOOD status.  
FN6976 Rev 2.00  
January 11, 2013  
Page 16 of 27  
ISL6265C  
and drives the clock, SVC, during a transaction. The AMD  
processor is always the master and the voltage regulators are the  
slaves. The slave receives the SVI transactions and acts  
accordingly. Mobile SVI wire protocol timing is based on high-  
speed mode I2C. See AMD Griffin (Family 11h) processor  
publications for additional details.  
TABLE 3. SERIAL VID CODES  
VOLTAGE (V) SVID[6:0]  
1.1500 100_0000b  
SVID[6:0]  
VOLTAGE (V)  
1.5500  
1.5375  
1.5250  
1.5125  
1.5000  
1.4875  
1.4750  
1.4625  
1.4500  
1.4375  
1.4250  
1.4125  
1.4000  
1.3875  
1.3750  
1.3625  
1.3500  
1.3375  
1.3250  
1.3125  
1.3000  
1.2875  
1.2750  
1.2625  
1.2500  
1.2375  
1.2250  
1.2125  
1.2000  
1.1875  
1.1750  
1.1625  
SVID[6:0]  
VOLTAGE (V)  
0.7500  
0.7375  
0.7250  
0.7125  
0.7000  
0.6875  
0.6750  
0.6625  
0.6500  
0.6375  
0.6250  
0.6125  
0.6000  
0.5875  
0.5750  
0.5625  
0.5500  
0.5375  
0.5250  
0.5125  
0.5000  
0.4875*  
0.4750*  
0.4625*  
0.4500*  
0.4375*  
0.4250*  
0.4125*  
0.4000*  
0.3875*  
0.3750*  
0.3625*  
SVID[6:0]  
VOLTAGE (V)  
0.3500*  
0.3375*  
0.3250*  
0.3125*  
0.3000*  
0.2875*  
0.2750*  
0.2625*  
0.2500*  
0.2375*  
0.2250*  
0.2125*  
0.2000*  
0.1875*  
0.1750*  
0.1625*  
0.1500*  
0.1375*  
0.1250*  
0.1125*  
0.1000*  
0.0875*  
0.0750*  
0.0625*  
0.0500*  
0.0375*  
0.0250*  
0.0125*  
OFF  
000_0000b  
000_0001b  
000_0010b  
000_0011b  
000_0100b  
000_0101b  
000_0110b  
000_0111b  
000_1000b  
000_1001b  
000_1010b  
000_1011b  
000_1100b  
000_1101b  
000_1110b  
000_1111b  
001_0000b  
001_0001b  
001_0010b  
001_0011b  
001_0100b  
001_0101b  
001_0110b  
001_0111b  
001_1000b  
001_1001b  
001_1010b  
001_1011b  
001_1100b  
001_1101b  
001_1110b  
001_1111b  
010_0000b  
010_0001b  
010_0010b  
010_0011b  
010_0100b  
010_0101b  
010_0110b  
010_0111b  
010_1000b  
010_1001b  
010_1010b  
010_1011b  
010_1100b  
010_1101b  
010_1110b  
010_1111b  
011_0000b  
011_0001b  
011_0010b  
011_0011b  
011_0100b  
011_0101b  
011_0110b  
011_0111b  
011_1000b  
011_1001b  
011_1010b  
011_1011b  
011_1100b  
011_1101b  
011_1110b  
011_1111b  
110_0000b  
110_0001b  
110_0010b  
110_0011b  
110_0100b  
110_0101b  
110_0110b  
110_0111b  
110_1000b  
110_1001b  
110_1010b  
110_1011b  
110_1100b  
110_1101b  
110_1110b  
110_1111b  
111_0000b  
111_0001b  
111_0010b  
111_0011b  
111_0100b  
111_0101b  
111_0110b  
111_0111b  
111_1000b  
111_1001b  
111_1010b  
111_1011b  
111_1100b  
111_1101b  
111_1110b  
111_1111b  
1.1375  
1.1250  
1.1125  
1.1000  
1.0875  
1.0750  
1.0625  
1.0500  
1.0375  
1.0250  
1.0125  
1.0000  
0.9875  
0.9750  
0.9625  
0.9500  
0.9375  
0.9250  
0.9125  
0.9000  
0.8875  
0.8750  
0.8625  
0.8500  
0.8375  
0.8250  
0.8125  
0.8000  
0.7875  
0.7750  
0.7625  
100_0001b  
100_0010b  
100_0011b  
100_0100b  
100_0101b  
100_0110b  
100_0111b  
100_1000b  
100_1001b  
100_1010b  
100_1011b  
100_1100b  
100_1101b  
100_1110b  
100_1111b  
101_0000b  
101_0001b  
101_0010b  
101_0011b  
101_0100b  
101_0101b  
101_0110b  
101_0111b  
101_1000b  
101_1001b  
101_1010b  
101_1011b  
101_1100b  
101_1101b  
101_1110b  
101_1111b  
OFF  
OFF  
OFF  
NOTE: *Indicates a VID not required for AMD Family 10h processors.  
FN6976 Rev 2.00  
January 11, 2013  
Page 17 of 27  
ISL6265C  
(See Table 3)  
SVID  
5
4
3
2
1
0
7
5
4
2
1
6
6
3
0
SVC  
SVD  
SLAVE ADDRESS PHASE  
DATA PHASE  
FIGURE 9. SEND BYTE EXAMPLE  
The ISL6265C controls the no-load output voltage of core and  
Northbridge output to an accuracy of ±0.5% over-the-range of 0.75V  
to 1.5V. A fully differential amplifier implements core voltage  
sensing for precise voltage control at the microprocessor die.  
SVI Bus Protocol  
The AMD processor bus protocol is compliant with SMBus send  
byte protocol for VID transactions (see Figure 9). During a send  
byte transaction, the processor sends the start sequence  
followed by the slave address of the VR for which the VID  
command applies. The address byte must be configured  
according to Table 4. The processor then sends the write bit. After  
the write bit, if the ISL6265C receives a valid address byte, it  
sends the acknowledge bit. The processor then sends the PSI-L  
bit and VID bits during the data phase. The Serial VID 8-bit data  
field encoding is outlined in Table 5. If ISL6265C receives a valid  
8-bit code during the data phase, it sends the acknowledge bit.  
Finally, the processor sends the stop sequence. After the  
ISL6265C has detected the stop, it can then proceed with the  
VID-on-the-fly transition.  
Switching Frequency  
The R3 modulator scheme is a variable frequency PWM  
architecture. The switching frequency increases during the  
application of a load to improve transient performance. It also  
varies slightly due to changes in input and output voltage and  
output current. This variation is normally less than 10% in  
continuous conduction mode.  
CORE FREQUENCY SELECTION  
A resistor connected between the VW and COMP pins of the Core  
segment of the ISL6265C adjusts the switching window and  
therefore adjusts the switching frequency. The RFSET resistor that  
sets up the switching frequency of the converter operating in  
CCM can be determined using Equation 3, where RFSET is in kΩ  
and the switching period is in ms. Designs for 300kHz switching  
frequency would result in a RFSET value of 6.81kΩ.  
TABLE 4. SVI SEND BYTE ADDRESS DESCRIPTION  
BITS  
DESCRIPTION  
6:4 Always 110b  
3
2
Reserved by AMD for future use  
VDD1, if set then the following data byte contains the VID for  
VDD1  
R
k = Periods0.4  2.33  
(EQ. 3)  
FSET  
1
0
VDD0, if set then the following data byte contains the VID for  
VID0  
In discontinuous conduction mode (DCM) the ISL6265C runs in  
period stretching mode.  
VDDNB, if set then the following data byte contains the VID for  
VIDNB  
NORTHBRIDGE FREQUENCY SELECTION  
The Northbridge switching frequency to programmed by a  
resistor connected from the FSET_NB pin to the GND pin. The  
approximate PWM switching frequency is written as shown in  
Equation 4:  
TABLE 5. SERIAL VID 8-BIT DATA FIELD ENCODING  
DESCRIPTION  
BITS  
7
PSI_L:  
1
(EQ. 4)  
-----------------------------------  
F
=
=0 means the processor is at an optimal load for the regulator(s)  
to enter power-savings mode  
SW  
K R  
FSETNB  
=1 means the processor is not at an optimal load for the  
regulator(s) to enter power-saving mode  
Estimating the value of RFSET_NB is written as shown in  
Equation 5:  
6:0 SVID[6:0] as defined in Table 3.  
1
K F  
--------------------  
(EQ. 5)  
R
=
FSET  
SW  
Operation  
Where FSW is the PWM switching frequency, RFSET_NB is the  
programming resistor and K = 1.5 x 10-10  
After the start-up sequence, the ISL6265C begins regulating the  
core and Northbridge output voltages to the pre-PWROK metal  
VID programmed. The controller monitors SVI commands to  
determine when to enter power-savings mode, implement  
dynamic VID changes, and shutdown individual outputs.  
.
It is recommended that whenever the control loop compensation  
network is modified, the switching frequency should be checked  
and adjusted by changing RFSET_NB if necessary.  
FN6976 Rev 2.00  
January 11, 2013  
Page 18 of 27  
ISL6265C  
selected, such that the R-C time constant matches the inductor  
L/DCR time constant (see Equation 9), then VC is equal to the  
voltage drop across the DCR multiplied by the ratio of the resistor  
divider, K.  
Current Sense  
Core and Northbridge regulators feature two different types of  
current sense circuits.  
R
R  
L
CORE CONTINUOUS CURRENT SENSE  
1
2
(EQ. 9)  
-------------  
--------------------  
C  
=
1
DCR  
R + R  
1 2  
The ISL6265C provides for load current to be measured using  
either resistors in series with the individual output inductors or  
using the intrinsic series resistance of the inductors as shown in  
the applications circuits in Figures 3 and 4. The load current in a  
particular output is sampled continuously every switching cycle.  
During this time, the current-sense amplifier uses the current  
sense inputs to reproduce a signal proportional to the inductor  
current. This sensed current is a scaled version of the inductor  
current.  
The inductor current sense information is used for current  
balance in dual plane applications, overcurrent detection in core  
outputs and output voltage droop depending on controller  
configuration.  
CORE DCR TEMPERATURE COMPENSATION  
It may also be necessary to compensate for changes in inductor  
DCR due to temperature. DCR shifts due to temperature cause  
time constant mismatch, skewing inductor current accuracy.  
Potential problems include output voltage droop and OC trip  
point, both shifting significantly from expected levels. The  
addition of a negative temperature coefficient (NTC) resistor to  
the R-C network compensates for the rise in DCR due to  
temperature. Typical NTC values are in the 10kΩ range. A second  
resistor, R3, in series with the NTC allows for more accurate time-  
constant and resistor-ratio matching as the pair of resistors are  
placed in parallel with R2 (Figure 10). The NTC resistor must be  
placed next to the inductor for good heat transfer, while R1, R2,  
R3, and C1 are placed close to the controller for interference  
immunity.  
I
V
IN  
L
UGATE  
LGATE  
L
DCR  
V
OUT  
MOSFET  
DRIVER  
INDUCTOR  
-
C
OUT  
V (s)  
L
-
V (s)  
C
R
C
1
1
2
R
ISL6265C INTERNAL CIRCUIT  
CORE DCR COMPONENT SELECTION FOR DROOP  
R
NTC  
OPTIONAL  
NTC  
NETWORK  
By adjusting the ratio between inductor DCR drop and the voltage  
measured across the sense capacitor, the load line can be set to  
any level, giving the converter the correct amount of droop at all  
load currents.  
ISP  
ISN  
R
3
CURRENT  
SENSE  
Equation 10 shows the relation between droop voltage,  
maximum output current (IMAX), OC trip level and current sense  
FIGURE 10. DCR SENSING COMPONENTS  
capacitor voltage at the OC current level, VC(OC)  
.
Inductor windings have a characteristic distributed resistance or  
DCR (Direct Current Resistance). For simplicity, the inductor DCR  
is considered as a separate lumped quantity, as shown in  
Figure 10. The inductor current, IL, flowing through the inductor,  
passes through the DCR. Equation 6 shows the s-domain  
equivalent voltage, VL, across the inductor.  
I
MAX  
(EQ. 10)  
-------------  
V
=
5 V  
DROOP  
COC  
I
OC  
AMD specifications do not require droop and provide no load line  
guidelines. Tight static output voltage tolerance limits push  
acceptable level of droop below a useful level for Griffin  
applications. Care must be taken in applications which  
implement droop to balance time constant mismatch, sense  
capacitor resistor ratio, OC trip and droop equations.  
Temperature shifts related to DCR must also be addressed, as  
outlined in the previous section.  
V s= I  s L + DCR  
(EQ. 6)  
L
L
A simple R-C network across the inductor (R1, R2 and C) extracts  
the DCR voltage, as shown in Equation 7. The voltage across the  
sense capacitor, VC, can be shown to be proportional to the  
output current IL, shown in Equation 7.  
NORTHBRIDGE CURRENT SENSE  
s L  
-------------  
+ 1  
(EQ. 7)  
DCR  
During the off-time following a PHASE transition low, the  
Northbridge controller samples the voltage across the lower  
MOSFET rDS(ON). A ground-referenced amplifier is connected to  
the PHASE node through a resistor, ROCSET_NB. The voltage across  
ROCSET_NB is equal to the voltage drop across the rDS(ON) of the  
lower MOSFET while it is conducting. The resulting current into  
the OCSET_NB pin is proportional to the inductor current. The  
sensed inductor current is used for overcurrent protection and  
described in the “Fault Monitoring and Protection” on page 21.  
The Northbridge controller does not support output voltage  
droop.  
----------------------------------------------------------  
V
s=  
K DCR I  
C
L
R R   
1
2
-----------------------  
s   
C + 1  
1
R
+ R  
2
1
Where:  
R
2
--------------------  
K =  
(EQ. 8)  
R
+ R  
1
2
Sensing the time varying inductor current accurately requires  
that the parallel R-C network time constant match the inductor  
L/DCR time constant. If the R-C network components are  
FN6976 Rev 2.00  
January 11, 2013  
Page 19 of 27  
ISL6265C  
PHASE pin low. The ISL6265C has an integrated boot diode  
connected from the PVCC pin to the BOOT pin.  
Selecting RBIAS For Core Outputs  
To properly bias the ISL6265C, a reference current is established  
by placing a 117kΩ, 1% tolerance resistor from the RBIAS pin to  
ground. This will provide a highly accurate, 10µA current source  
from which OC reference current is derived.  
Diode Emulation  
The ISL6265C implements forced continuous-conduction-mode  
(CCM) at heavy load and diode-emulation-mode (DE) at light load,  
to optimize efficiency in the entire load range. The transition is  
automatically achieved by detecting the inductor current when  
PSI_L is low. If PSI_L is high, the controller disables DE and  
forces CCM on both Core and NB regulators.  
Care must be taken in layout to place the resistor very close to  
the RBIAS pin. A good quality signal ground should be connected  
to the opposite end of the RBIAS resistor. Do not connect any  
other components to this pin as this would negatively impact  
performance. Capacitance on this pin could create instabilities  
and is to be avoided.  
Positive-going inductor current flows either from the source of  
the high-side MOSFET, or into the drain of the low-side MOSFET.  
Negative-going inductor current flows into the drain of the low-  
side MOSFET. When the low-side MOSFET conducts positive  
inductor current, the phase voltage is negative with respect to the  
GND and PGND pins. Conversely, when the low-side MOSFET  
conducts negative inductor current, the phase voltage is positive  
with respect to the GND and PGND pins. The ISL6265C monitors  
the phase voltage when the low-side MOSFET is conducting  
inductor current to determine the direction of the inductor  
current.  
A resistor divider off this pin is used to set the Core side OC trip  
level. Additional direction on how to size is provided in “Fault  
Monitoring and Protection” on page 21 on how to size the resistor  
divider.  
Offset Resistor Selection  
If the OFS pin is connected to ground through a resistor, the  
ISL6265C operates in SVI mode with droop active. The resistor  
between the OFS pin and ground sets the positive Core voltage  
offset per Equation 11.  
When the output load current is less than half the inductor ripple  
current, the inductor current goes negative. Sinking the negative  
inductor through the low-side MOSFET lowers efficiency by  
preventing DCM period stretching and allowing unnecessary  
conduction losses. In DE, the ISL6265C Core regulators  
automatically enter DCM after the PHASE pin has detected  
positive voltage and LGATE was allowed to go high. The NB  
regulator enters DCM after the PHASE pin has detected positive  
voltage and LGATE was allowed to go high for eight consecutive  
PWM switching cycles. The ISL6265C turns off the low-side  
MOSFET once the phase voltage turns positive, indicating  
negative inductor current. The ISL6265C returns to CCM on the  
following cycle after the PHASE pin detects negative voltage,  
indicating that the body diode of the low-side MOSFET is  
conducting positive inductor current.  
1.2V R  
FB  
----------------------------  
R
=
(EQ. 11)  
OFS  
V
OFS  
Where VOFS is the user defined output voltage offset. Typically,  
VOFS is determined by taking half the total output voltage droop.  
The resulting value centers the overall output voltage waveform  
around the programmed SVID level. For example, RFB of 1kΩ and  
a total output droop of 24mV would result in an offset voltage of  
12mV and a ROFS of 100kΩ.  
Internal Driver Operation  
The ISL6265C features three internal gate-drivers to support the  
Core and Northbridge regulators and to reduce solution size. The  
drivers include a diode emulation mode, which helps to improve  
light-load efficiency.  
Efficiency can be further improved with a reduction of  
unnecessary switching losses by reducing the PWM frequency. It  
is characteristic of the R3 architecture for the PWM frequency to  
decrease while in diode emulation. The extent of the frequency  
reduction is proportional to the reduction of load current. Upon  
entering DCM, the PWM frequency makes an initial  
step-reduction because of a 33% step-increase of the window  
voltage VW.  
MOSFET Gate-Drive Outputs  
The ISL6265C has internal gate-drivers for the high-side and low-  
side N-Channel MOSFETs. The low-side gate-drivers are optimized  
for low duty-cycle applications where the low-side MOSFET  
conduction losses are dominant, requiring a low rDS(ON) MOSFET.  
The LGATE pull-down resistance is low in order to strongly clamp  
the gate of the MOSFET below the VGS(th) at turn-off. The current  
transient through the gate at turn-off can be considerable  
because the gate charge of a low rDS(ON) MOSFET can be large.  
Adaptive shoot-through protection prevents a gate-driver output  
from turning on until the opposite gate-driver output has fallen  
below approximately 1V.  
Power-Savings Mode  
The ISL6265C has two operating modes to optimize efficiency  
based on the state of the PSI_L input from the AMD SVI control  
signal. When this input is low, the controller expects to deliver  
low power and enters a power-savings mode to improve  
efficiency in this low power state. The controller’s operational  
modes are designed to work in conjunction with the AMD SVI  
control signal to maintain the optimal system configuration for  
all conditions.  
The high-side gate-driver output voltage is measured across the  
UGATE and PHASE pins while the low-side gate-driver output  
voltage is measured across the LGATE and PGND pins. The power  
for the LGATE gate driver is sourced directly from the PVCC pin.  
The power for the UGATE gate-driver is sourced from a “boot”  
capacitor connected across the BOOT and PHASE pins. The boot  
capacitor is charged from a 5V bias supply through a “boot  
diode” each time the low-side MOSFET turns on, pulling the  
Northbridge and Dual Plane Core  
While PSI_L is high, the controller operates all three regulators in  
forced CCM. If PSI_L is asserted low by the SVI interface, the  
FN6976 Rev 2.00  
January 11, 2013  
Page 20 of 27  
ISL6265C  
ISL6265C initiates DE in all three regulators. This transition  
allows the controller to achieve the highest possible efficiency  
over the entire load range for each output. A smooth transition is  
facilitated by the R3 technology, which correctly maintains the  
internally synthesized ripple current throughout mode transitions  
of each regulator.  
controller uses lower MOSFET rDS(ON) sensing to detect output  
current.  
CORE OC DETECTION  
Core outputs feature an OC monitor which compares a voltage set at  
the OCSET pin to the voltage measured across the current sense  
capacitor, VC. When the voltage across the current sense capacitor  
exceeds the programmed trip level, the comparator signals an OC fault.  
Figure 11 shows the basic OC functions within the IC.  
Uniplane Core  
In uniplane mode, the ISL6265C Core regulator is in 2-phase  
multiphase mode. The controller operates with both phases fully  
active, responding rapidly to transients and delivering the  
maximum power to the load. When the processor asserts PSI_L  
low under reduced load levels, the ISL6265C sheds one phase to  
eliminate switching losses associated with the idle channel. Even  
with the regulator operating in single-phase mode, transient  
response capability is maintained.  
SEE FIGURE 9 FOR  
ADDITIONAL DETAIL  
CURRENT  
SENSE  
ISP  
ISN  
+
V
c
5x  
_
While operating in single-phase DE with PSI_L low, the lower  
MOSFET driver switches the lower MOSFET off at the point of zero  
inductor current to prevent discharge current from flowing from  
the output capacitor bank through the inductor. In DCM,  
switching frequency is proportionately reduced, thus greatly  
reducing both conduction and switching loss. In DCM, the  
5 x V  
@
C(OC)  
1.17V  
R
OC TRIP CURRENT  
BIAS  
BIAS  
CKT  
10µA  
R
BIAS  
OC  
-
OCSET  
V
+
6
OCSET  
V
OCSET  
R
OCSET  
switching frequency is defined by Equation 12.  
6
2
ISL6265C  
F
2 L I  
O
CCM  
------------------- -------------------------------------  
F
=
(EQ. 12)  
DCM  
2
V
1.33  
O
---------  
V
1 –  
O
FIGURE 11. OC TRIP CIRCUITRY  
V
IN  
The sense capacitor voltage, VC, will increase as inductor current  
rises per Equation 7. When the inductor current rises to the OC  
trip level, the voltage across the sense capacitor will reach a  
maximum based on the resistor ratio K. This maximum value,  
VC(OC), is gained up by a factor of 5 and compared to the static OC  
trip level set by the OCSET pin.  
Where FCCM is equivalent to the Core frequency set by Equation 3.  
Fault Monitoring and Protection  
The ISL6265C actively monitors Core and Northbridge output  
voltages and currents to detect fault conditions. These fault  
monitors trigger protective measures to prevent damage to the  
processor. One common power good indicator is provided for  
linking to external system monitors.  
The recommended voltage range for VC,OC is 6mV to 25mV,  
which sets the resistor divider ratio K, where IOC is the  
user-defined OC trip level (see Equation 13). Typical inductor DCR  
values are on the order of 1mΩ which result in more than enough  
voltage drop to support this VC,OC range.  
Power-Good Signal  
The power-good pin (PGOOD) is an open-drain logic output that  
signals if the ISL6265C is not regulating Core and Northbridge  
output voltages within the proper levels or output current in one  
or more outputs has exceeded the maximum current setpoint.  
V
COC  
DCR  
(EQ. 13)  
---------------------------  
K =  
I
OC  
The resistor divider components also impact time-constant  
matching, these components need to meet the parallel  
combination requirements of Equation 9.  
This pin must be tied to a +3.3V or +5V source through a resistor.  
During shutdown and soft-start, PGOOD is pulled low and is  
released high only after a successful soft-start has raised Core  
and Northbridge output voltages within operating limits. PGOOD  
is pulled low when an overvoltage, undervoltage, or overcurrent  
(OC) condition is detected on any output or when the controller is  
disabled by a POR or forcing enable (EN) low. Once a fault  
condition is triggered, the controller acts to protect the processor.  
The controller latches off and PGOOD is pulled low. Toggling EN  
or VCC initiates a soft-start of all outputs. In the event of an OV,  
the controller will not initiate a soft-start by toggling EN, but  
requires VCC be lowered below the falling POR threshold to reset.  
Based on the selected VC(OC) level, the required OC monitor trip  
level is set. The recommended VC(OC) level range will result in an  
OC monitor trip level range of 30mV to 125mV based on the  
internal gain of 5.  
This OC monitor trip level sets the voltage level required at the  
OCSET pin to create an OC fault at the user-defined OC trip level.  
A resistor divider from the RBIAS pin to ground with the mid-point  
connected to OCSET sets the voltage at the pin (see Figure 11).  
This voltage is internally divided by 6 and compared with VC(OC)  
Working backwards, the voltage required at the OCSET pin to  
achieve this OC trip level ranges from 180mV to 0.750mV as  
defined in Equation 14.  
.
Overcurrent Protection  
Core and Northbridge outputs feature two different methods of  
current sensing. Core output current sensing is achieved via  
inductor DCR or discrete resistor sensing. The Northbridge  
(EQ. 14)  
V
= V  
30  
COC  
OCSET  
FN6976 Rev 2.00  
January 11, 2013  
Page 21 of 27  
ISL6265C  
The resistor divider ratio used to determine the RBIAS and ROCSET  
values is shown in Equation 15.  
value by a nominal 295mV for 205µs. The PWM outputs turn off  
both Core and Northbridge internal drivers and PGOOD goes low.  
R
V
OCSET  
1.17V  
OCSET  
(EQ. 15)  
-----------------------------------------------  
-----------------------  
=
General Application Design  
Guide  
This design guide is intended to provide a high-level explanation of  
the steps necessary to design a single-phase power converter. It is  
assumed that the reader is familiar with many of the basic skills  
and techniques referenced in the following section. In addition to  
this guide, Intersil provides complete reference designs that  
include schematics, bills of materials, and example board layouts.  
R
+ R  
OCSET  
BIAS  
The resistor values must also meet the RBIAS requirement that  
the total series resistance to ground equal 117kΩ. An OC  
condition must be sustained for 100µs before action is taken by  
the controller in response to the OC fault.  
A short-circuit OC loop is also active based on the same sense  
elements outlined above with a threshold set to 2.25x the OCSET  
threshold set. The controller takes immediate action when this  
fast OC fault is detected.  
Selecting the LC Output Filter  
The output inductor and output capacitor bank form a low-pass  
filter responsible for smoothing the pulsating voltage at the  
phase node. The output filter also must support the transient  
energy required by the load until the controller can respond.  
Because it has a low bandwidth compared to the switching  
frequency, the output filter limits the system transient response.  
The output capacitors must supply or sink load current while the  
current in the output inductors increases or decreases to meet  
the demand.  
NORTHBRIDGE OC DETECTION  
Northbridge OC sensing is achieved via rDS(ON) sensing across the  
lower MOSFET. An internal 10µA current source develops a  
voltage across ROCSET_NB, which is compared with the voltage  
developed across the low-side MOSFET as measured at the  
PHASE pin. When the voltage drop across the MOSFET exceeds  
the voltage drop across the resistor, an OC event occurs. The  
OCSET_NB resistor is selected based on the relationship in  
Equation 16.  
The duty cycle of an ideal buck converter is a function of the  
input and the output voltage. This relationship is written as  
Equation 17:  
I
r  
OC DSON  
(EQ. 16)  
------------------------------------  
=
R
OCSETNB  
10A  
V
O
Where IOC is the OC trip level selected for the Northbridge  
application and rDS(ON) is the drain-source ON-resistance of the  
lower MOSFET.  
---------  
D =  
(EQ. 17)  
V
IN  
The output inductor peak-to-peak ripple current is written as  
Equation 18:  
OC FAULT RESPONSE  
V
O 1 D  
When an OC fault occurs on any combination of outputs, both  
Core and Northbridge regulators shutdown and the driver outputs  
are tri-stated. The PGOOD signal transitions low indicating a fault  
condition. The controller will not attempt to restart the regulators  
and the user must toggle either EN or VCC to clear the fault  
condition.  
-----------------------------  
(EQ. 18)  
I
=
P-P  
SW L  
f
For this type of application, a typical step-down DC/DC converter  
has an IP-P of 20% to 40% of the maximum DC output load  
current. The value of IP-P is selected based upon several criteria  
such as MOSFET switching loss, inductor core loss, and the  
resistive loss of the inductor winding. The DC copper loss of the  
inductor can be estimated by Equation 19:  
Overvoltage Protection  
The ISL6265C monitors the individual Core and Northbridge  
output voltages using differential remote sense amplifiers. The  
ISL6265C features a severe overvoltage (OV) threshold of 1.8V. If  
any of the outputs exceed this voltage, an OV fault is immediately  
triggered. PGOOD is latched low and the low-side MOSFETs of the  
offending output(s) are turned on. The low-side MOSFETs will  
remain on until the output voltage is pulled below 0.85V at which  
time all MOSFETs are turned off. If the output again rises above  
1.8V, the protection process repeats. This offers protection  
against a shorted high-side MOSFET while preventing output  
voltage from ringing below ground. The OV is reset by toggling EN  
low. OV detection is active at all times that the controller is  
enabled including after one of the other faults occurs so that the  
processor is protected against high-side MOSFET leakage while  
the MOSFETs are commanded off.  
2
P
= I  
DCR  
(EQ. 19)  
COPPER  
LOAD  
Where ILOAD is the converter output DC current.  
The copper loss can be significant so attention must be given to  
the DCR selection. Another factor to consider when choosing the  
inductor is its saturation characteristics at elevated temperature.  
A saturated inductor could cause destruction of circuit  
components as well as nuisance OCP faults.  
A DC/DC buck regulator must have output capacitance CO into  
which ripple current IP-P can flow. Current IP-P develops a  
corresponding ripple voltage VP-P across CO, which is the sum of  
the voltage drop across the capacitor ESR and of the voltage  
change stemming from charge moved in and out of the  
capacitor. These two voltages are written as shown in  
Equation 20:  
Undervoltage Protection  
Undervoltage protection is independent of the OC limit. A fault  
latches if any of the sensed output voltages are less than the VID set  
(EQ. 20)  
V  
= I  
PP ESR  
ESR  
FN6976 Rev 2.00  
January 11, 2013  
Page 22 of 27  
ISL6265C  
and Equation 21:  
Where:  
- IMAX is the maximum continuous ILOAD of the converter  
I
PP  
-----------------------------  
(EQ. 21)  
V  
=
C
O f  
8C  
SW  
- IPP,N is the ratio of inductor peak-to-peak ripple current to  
IMAX  
If the output of the converter has to support a load with high  
pulsating current, several capacitors will need to be paralleled to  
reduce the total ESR until the required VP-P is achieved. The  
inductance of the capacitor can cause a brief voltage dip if the  
load transient has an extremely high slew rate. Capacitor ESL can  
significantly impact output voltage ripple. Low inductance  
capacitors should be considered. A capacitor dissipates heat as a  
function of RMS current and frequency. Be sure that IP-P is shared  
by a sufficient quantity of paralleled capacitors so that they  
operate below the maximum rated RMS current at FSW. Take into  
account that the rated value of a capacitor can degrade as much  
as 50% as the DC voltage across it increases.  
- D is the duty cycle that is adjusted to take into account the  
efficiency of the converter which is written as:  
V
O
(EQ. 23)  
-----------------  
D =  
V
   
IN  
- where is converter efficiency  
Figure 13 provides the same input RMS current information for  
two-phase designs.  
0.3  
Selection of the Input Capacitor  
0.2  
The input capacitors are responsible for sourcing the AC  
component of the input current flowing into the upper MOSFETs.  
Their RMS current capability must be sufficient to handle the AC  
component of the current drawn by the upper MOSFETs, which is  
related to duty cycle and the number of active phases.  
I
= 0.5  
P-P,N  
I
= 0.75  
0.1  
P-P,N  
I
= 0  
P-P,N  
The important parameters for the bulk input capacitance are the  
voltage rating and the RMS current rating. For reliable operation,  
select bulk capacitors with voltage and current ratings above the  
maximum input voltage and capable of supplying the RMS  
current required by the switching circuit. Their voltage rating  
should be at least 1.25x greater than the maximum input  
voltage, while a voltage rating of 1.5x is a preferred rating.  
Figure 12 is a graph of the input RMS ripple current, normalized  
relative to output load current, as a function of duty cycle for a  
single-phase regulator that is adjusted for converter efficiency.  
0
0
0.2  
0.4  
0.6  
0.8  
1.0  
DUTY CYCLE (V V )  
IN/  
O
FIGURE 13. NORMALIZED RMS INPUT CURRENT FOR  
2-PHASE CONVERTER  
In addition to the bulk capacitance, some low ESL ceramic  
capacitance is recommended to decouple between the drain of  
the high-side MOSFET and the source of the low-side MOSFET.  
0.60  
I
= 0.50  
I
= 1  
P-P,N  
P-P,N  
0.55  
0.50  
0.45  
0.40  
0.35  
0.30  
0.25  
0.20  
0.15  
0.10  
0.05  
0
MOSFET Selection and Considerations  
I
= 0.75  
P-P,N  
The choice of MOSFETs depends on the current each MOSFET will  
be required to conduct, the switching frequency, the capability of  
the MOSFETs to dissipate heat, and the availability and nature of  
heat sinking and air flow.  
I
= 0  
P-P,N  
I
= 0.25  
P-P,N  
Typically, a MOSFET cannot tolerate even brief excursions beyond  
their maximum drain to source voltage rating. The MOSFETs used  
in the power stage of the converter should have a maximum VDS  
rating that exceeds the sum of the upper voltage tolerance of the  
input power source and the voltage spike that occurs when the  
MOSFETs switch.  
0
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9  
DUTY CYCLE (V V )  
1.0  
There are several power MOSFETs readily available that are  
optimized for DC/DC converter applications. The preferred high-  
side MOSFET emphasizes low gate charge so that the device  
spends the least amount of time dissipating power in the linear  
region. The preferred low-side MOSFET emphasizes low r DS(ON)  
when fully saturated to minimize conduction loss.  
IN/  
O
FIGURE 12. NORMALIZED RMS INPUT CURRENT FOR  
SINGLE PHASE CONVERTER  
The normalized RMS current calculation is written as Equation 22:  
For the low-side (LS) MOSFET, the power loss can be assumed to  
be conductive only and is written as Equation 24:  
2
D
12  
------  
I
=
D  1 D+  
I  
(EQ. 22)  
IN_RMSN  
PP,N  
2
P
I  
r  
DSON_LS 1 D  
(EQ. 24)  
CON_LS  
LOAD  
FN6976 Rev 2.00  
January 11, 2013  
Page 23 of 27  
ISL6265C  
For the high-side (HS) MOSFET, the its conduction loss is written  
as Equation 25:  
Component Placement  
There are two sets of critical components in a DC/DC converter;  
the power components and the small signal components. The  
power components are the most critical because they switch  
large amount of energy. The small signal components connect to  
sensitive nodes or supply critical bypassing current and signal  
coupling.  
2
P
= I  
r  
DSON_HS D  
(EQ. 25)  
CON_HS  
LOAD  
For the high-side MOSFET, the switching loss is written as  
Equation 26:  
IN IVALLEY tON f  
V
V
IN IPEAK tOFF f  
SW  
SW  
---------------------------------------------------------------- -------------------------------------------------------------  
P
=
+
The power components should be placed first and these include  
MOSFETs, input and output capacitors, and the inductor. It is  
important to have a symmetrical layout for each power train,  
preferably with the controller located equidistant from each  
power train. Symmetrical layout allows heat to be dissipated  
equally across all power trains. Keeping the distance between  
the power train and the control IC short helps keep the gate drive  
traces short. These drive signals include the LGATE, UGATE,  
PGND, PHASE and BOOT.  
SW_HS  
2
2
(EQ. 26)  
Where:  
- IVALLEY is the difference of the DC component of the inductor  
current minus 1/2 of the inductor ripple current  
- IPEAK is the sum of the DC component of the inductor current  
plus 1/2 of the inductor ripple current  
- tON is the time required to drive the device into saturation  
- tOFF is the time required to drive the device into cut-off  
GND  
VIAS TO  
Selecting The Bootstrap Capacitor  
GROUND  
PLANE  
OUTPUT  
CAPACITORS  
All three integrated drivers feature an internal bootstrap Schottky  
diode. Simply adding an external capacitor across the BOOT and  
PHASE pins completes the bootstrap circuit. The bootstrap  
function is also designed to prevent the bootstrap capacitor from  
overcharging due to the large negative swing at the PHASE node.  
This reduces voltage stress on the BOOT and PHASE pins.  
SCHOTTKY  
DIODE  
VOUT  
PHASE  
NODE  
LOW-SIDE  
MOSFETS  
INDUCTOR  
HIGH-SIDE  
MOSFETS  
INPUT  
CAPACITORS  
VIN  
The bootstrap capacitor must have a maximum voltage rating  
above PVCC + 4V and its capacitance value is selected per  
Equation 27:  
FIGURE 14. TYPICAL POWER COMPONENT PLACEMENT  
Q
g
When placing MOSFETs, try to keep the source of the upper  
MOSFETs and the drain of the lower MOSFETs as close as  
thermally possible (see Figure 14). Input high-frequency  
capacitors should be placed close to the drain of the upper  
MOSFETs and the source of the lower MOSFETs. Place the output  
inductor and output capacitors between the MOSFETs and the  
load. High-frequency output decoupling capacitors (ceramic)  
should be placed as close as possible to the decoupling target  
(microprocessor), making use of the shortest connection paths to  
any internal planes. Place the components in such a way that the  
area under the IC has less noise traces with high dV/dt and di/dt,  
such as gate signals and phase node signals.  
-----------------------  
C
(EQ. 27)  
BOOT  
V  
BOOT  
Where:  
- Qg is the total gate charge required to turn on the high-side  
MOSFET  
- VBOOT, is the maximum allowed voltage decay across the  
boot capacitor each time the high-side MOSFET is switched  
on  
As an example, suppose the high-side MOSFET has a total gate  
charge Qg, of 25nC at VGS = 5V, and a VBOOT of 200mV. The  
calculated bootstrap capacitance is 0.125µF; for a comfortable  
margin, select a capacitor that is double the calculated  
capacitance. In this example, 0.22µF will suffice. Use a low  
temperature-coefficient ceramic capacitor.  
Signal Ground and Power Ground  
The bottom of the ISL6265C QFN package is the signal ground  
(GND) terminal for analog and logic signals of the IC. Connect the  
GND pad of the ISL6265C to the island of ground plane under the  
top layer using several vias, for a robust thermal and electrical  
conduction path. Connect the input capacitors, the output  
capacitors, and the source of the lower MOSFETs to the power  
ground plane.  
PCB Layout Considerations  
Power and Signal Layers Placement on the  
PCB  
As a general rule, power layers should be close together, either  
on the top or bottom of the board, with the weak analog or logic  
signal layers on the opposite side of the board. The ground-plane  
layer should be adjacent to the signal layer to provide shielding.  
The ground plane layer should have an island located under the  
IC, the compensation components, and the FSET components.  
The island should be connected to the rest of the ground plane  
layer at one point.  
Routing and Connection Details  
Specific pins (and the trace routing from them), require extra  
attention during the layout process. The following sub-sections  
outline concerns by pin name.  
FN6976 Rev 2.00  
January 11, 2013  
Page 24 of 27  
ISL6265C  
PGND PINS  
FSET_NB PIN  
This is the return path for the pull-down of the LGATE low-side  
MOSFET gate driver. Ideally, PGND should be connected to the  
source of the low-side MOSFET with a low-resistance, low-  
inductance path.  
This pin requires a quiet environment. The resistor RFSET should  
be placed directly adjacent to this pin. Keep fast moving nodes  
away from this pin.  
LGATE ROUTING  
VIN PIN  
The LGATE trace has a signal going through it that is both high  
dV/dt and di/dt, with high peak charging and discharging  
current. Route this trace in parallel with the trace from the PGND  
pin. These two traces should be short, wide, and away from other  
traces. There should be no other weak signal traces in proximity  
with these traces on any layer.  
The VIN pin should be connected close to the drain of the high-  
side MOSFET, using a low- resistance and low-inductance path.  
VCC PIN  
For best performance, place the decoupling capacitor very close  
to the VCC and GND pins.  
BOOT AND PHASE ROUTING  
PVCC PIN  
The signals going through these traces are both high dv/dt and  
high di/dt, with high peak charging and discharging current.  
Route the UGATE and PHASE pins in parallel with short and wide  
traces. There should be no other weak signal traces in proximity  
with these traces on any layer.  
For best performance, place the decoupling capacitor very close  
to the PVCC and respective PGND pins, preferably on the same  
side of the PCB as the ISL6265C IC.  
ENABLE AND PGOOD PINS  
Copper Size for the Phase Node  
These are logic signals that are referenced to the GND pin. Treat  
as a typical logic signal.  
The parasitic capacitance and parasitic inductance of the phase  
node should be kept very low to minimize ringing. It is best to  
limit the size of the PHASE node copper in strict accordance with  
the current and thermal management of the application. An  
MLCC should be connected directly across the drain of the upper  
MOSFET and the source of the lower MOSFET to suppress the  
turn-off voltage.  
FB PINS  
The input impedance of the FB pin is high, so place the voltage  
programming and loop compensation components close to the  
COMP, FB, and GND pins keeping the high impedance trace  
short.  
FN6976 Rev 2.00  
January 11, 2013  
Page 25 of 27  
ISL6265C  
Revision History  
The revision history provided is for informational purposes only and is believed to be accurate, but not warranted. Please go to web to make sure you  
have the latest Rev.  
DATE  
REVISION  
FN6976.2  
CHANGE  
November 7, 2012  
Converted to new template.  
page 3 - Ordering Information table, added industrial part number ISL6265CIRTZ.  
In “Electrical Specifications” table, corrected conditions and standard over temp note in common conditions of  
Spec table from: "VCC = PVCC = 5V, VIN = 12V, Boldface limits apply over the operating temperature range,  
-10°C to +100°C." to: “VCC = PVCC = 5V, VIN = 12V, TA = -10°C to +100°C (ISL6265HRTZ), TA = -40°C to  
+100°C (ISL6265IRTZ), unless otherwise specified. Boldface limits apply across the operating temperature  
range, -40°C to +100°C.”  
July 23, 2010  
FN6976.1  
Added “Related Literature*” on page 1.  
On page 3; corrected part marking in “Ordering Information” from ISL6265C HRTZ to 6265C HRTZ  
In “Thermal Information” on page 10, corrected Theta JC from 32 to 28  
In “Electrical Specifications” table, corrected standard over temp note in common conditions of Spec table from  
"Boldface limits apply over the operating temperature range, -40°C to +85°C." to "Boldface limits apply over  
the operating temperature range, -10°C to +100°C."  
On “Overvoltage Threshold” on page 12; changed typical from 1.795V to 1.800V and maximum from 1.820V to  
1.825V.  
March 10, 2010  
FN6976.0  
Initial Release.  
About Intersil  
Intersil Corporation is a leader in the design and manufacture of high-performance analog, mixed-signal and power management  
semiconductors. The company's products address some of the fastest growing markets within the industrial and infrastructure,  
personal computing and high-end consumer markets. For more information about Intersil or to find out how to become a member of  
our winning team, visit our website and career page at www.intersil.com.  
For a complete listing of Applications, Related Documentation and Related Parts, please see the respective product information page.  
Also, please check the product information page to ensure that you have the most updated datasheet: ISL6265C  
To report errors or suggestions for this datasheet, please go to: www.intersil.com/askourstaff  
Reliability reports are available from our website at: http://rel.intersil.com/reports/search.php  
© Copyright Intersil Americas LLC 2010-2013. All Rights Reserved.  
All trademarks and registered trademarks are the property of their respective owners.  
For additional products, see www.intersil.com/en/products.html  
Intersil products are manufactured, assembled and tested utilizing ISO9001 quality systems as noted  
in the quality certifications found at www.intersil.com/en/support/qualandreliability.html  
Intersil products are sold by description only. Intersil may modify the circuit design and/or specifications of products at any time without notice, provided that such  
modification does not, in Intersil's sole judgment, affect the form, fit or function of the product. Accordingly, the reader is cautioned to verify that datasheets are  
current before placing orders. Information furnished by Intersil is believed to be accurate and reliable. However, no responsibility is assumed by Intersil or its  
subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result from its use. No license is granted by implication or  
otherwise under any patent or patent rights of Intersil or its subsidiaries.  
For information regarding Intersil Corporation and its products, see www.intersil.com  
FN6976 Rev 2.00  
January 11, 2013  
Page 26 of 27  
ISL6265C  
Package Outline Drawing  
L48.6x6  
48 LEAD THIN QUAD FLAT NO-LEAD PLASTIC PACKAGE  
Rev 1, 4/07  
4X  
4.4  
6.00  
0.40  
44X  
A
6
B
PIN #1 INDEX AREA  
48  
37  
6
1
36  
PIN 1  
INDEX AREA  
4 .40 ± 0.15  
25  
12  
0.15  
(4X)  
13  
24  
0.10 M C A B  
C
0.05 M  
TOP VIEW  
48X 0.45 ± 0.10  
BOTTOM VIEW  
4
48X 0.20  
SEE DETAIL "X"  
C
0.10  
C
MAX 0.80  
BASE PLANE  
SEATING PLANE  
0.08  
( 44 X 0 . 40 )  
( 5. 75 TYP )  
(
C
SIDE VIEW  
4. 40 )  
5
0 . 2 REF  
C
( 48X 0 . 20 )  
( 48X 0 . 65 )  
0 . 00 MIN.  
0 . 05 MAX.  
DETAIL "X"  
TYPICAL RECOMMENDED LAND PATTERN  
NOTES:  
1. Dimensions are in millimeters.  
Dimensions in ( ) for Reference Only.  
2. Dimensioning and tolerancing conform to AMSE Y14.5m-1994.  
3.  
Unless otherwise specified, tolerance : Decimal ± 0.05  
4. Dimension b applies to the metallized terminal and is measured  
between 0.15mm and 0.30mm from the terminal tip.  
Tiebar shown (if present) is a non-functional feature.  
5.  
6.  
The configuration of the pin #1 identifier is optional, but must be  
located within the zone indicated. The pin #1 identifier may be  
either a mold or mark feature.  
FN6976 Rev 2.00  
January 11, 2013  
Page 27 of 27  

相关型号:

SI9130DB

5- and 3.3-V Step-Down Synchronous Converters

Warning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
-
VISHAY

SI9135LG-T1

SMBus Multi-Output Power-Supply Controller

Warning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
-
VISHAY

SI9135LG-T1-E3

SMBus Multi-Output Power-Supply Controller

Warning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
-
VISHAY

SI9135_11

SMBus Multi-Output Power-Supply Controller

Warning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
-
VISHAY

SI9136_11

Multi-Output Power-Supply Controller

Warning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
-
VISHAY

SI9130CG-T1-E3

Pin-Programmable Dual Controller - Portable PCs

Warning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
-
VISHAY

SI9130LG-T1-E3

Pin-Programmable Dual Controller - Portable PCs

Warning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
-
VISHAY

SI9130_11

Pin-Programmable Dual Controller - Portable PCs

Warning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
-
VISHAY

SI9137

Multi-Output, Sequence Selectable Power-Supply Controller for Mobile Applications

Warning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
-
VISHAY

SI9137DB

Multi-Output, Sequence Selectable Power-Supply Controller for Mobile Applications

Warning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
-
VISHAY

SI9137LG

Multi-Output, Sequence Selectable Power-Supply Controller for Mobile Applications

Warning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
-
VISHAY

SI9122E

500-kHz Half-Bridge DC/DC Controller with Integrated Secondary Synchronous Rectification Drivers

Warning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
-
VISHAY