TPS56302PWPR [ETC]

SMPS Controller ; SMPS控制器\n
TPS56302PWPR
型号: TPS56302PWPR
厂家: ETC    ETC
描述:

SMPS Controller
SMPS控制器\n

控制器
文件: 总34页 (文件大小:810K)
中文:  中文翻译
下载:  下载PDF数据表文档文件
TPS56302  
DUAL-OUTPUT LOW-INPUT-VOLTAGE  
DSP POWER SUPPLY CONTROLLER WITH SEQUENCING  
SLVS289A – MARCH 2000 – REVISED OCTOBER 2000  
PWP PowerPAD PACKAGE  
(TOP VIEW)  
2.8 V – 5.5 V Input Voltage Range  
Programmable Dual Output Controller  
Supports Popular DSP, FPGA and  
Microcontroller Core and I/O Voltages  
– Switching Regulator Controls I/O Voltage  
– Low Dropout Controller Regulates Core  
Voltage  
1
28  
27  
26  
25  
24  
23  
22  
21  
20  
19  
18  
17  
16  
15  
VID0  
VID1  
SLOWST  
VHYST  
DROOP  
OCP  
IOUT  
PWRGD  
VSEN–LDO  
NGATE–LDO  
INHIBIT  
2
3
4
5
VREFB  
6
VSEN–RR  
ANAGND  
BIAS  
VLDODRV  
CPC1  
Thermal  
Pad  
Adjustable Slow-Start for Simultaneous  
Powerup of Both Outputs  
7
8
IOUTLO  
Power Good Output Monitors Both Outputs  
9
HISENSE  
LOSENSE/LOHIB  
HIGHDR  
BOOT  
BOOTLO  
LOWDR  
Fast Ripple Regulator Reduces Bulk  
Capacitance for Lower System Costs  
10  
11  
12  
13  
14  
V
CC  
CPC2  
VDRV  
DRVGND  
±1.5% Reference Voltage Tolerance  
Efficiencies Greater Than 90%  
Overvoltage, Undervoltage, and Adjustable  
Overcurrent Protection  
AVAILABLE VID CODE RANGES  
TPS56302  
Drives Logic Level N-Channel MOSFETs  
Through Entire Input Voltage Range  
OUTPUTS  
TPS56300  
V
–LDO  
1.3 V TO 2.5 V  
1.3 V TO 3.3 V  
1.3 V TO 3.3 V  
1.3 V TO 2.5 V  
Evaluation Module TPS56302EVM–163  
Available  
OUT  
V
–Switcher  
OUT  
NOTE: See Table 1 for actual VID codes.  
description  
The high-performance TPS56302 synchronous-buck regulator provides two supply voltages to power the core  
and I/O of digital signal processors. The TPS56302 is identical to the TPS56300 except that the reference  
voltages of the LDO and switching regulator have been reversed. The switching regulator, using hysteretic  
control with droop compensation, supports high current and efficiency for the I/O and other peripheral  
components. The LDO controller, suitable for powering the core voltage, drives an external N-channel power  
MOSFET and functions as an LDO regulator and as a power distribution switch.  
typical design  
V
I
(2.8 V – 5.5 V)  
U1  
TPS56302PWP  
V
CC  
CPC1  
PWRGD  
CPC2  
NGATE–LDO  
VREFB  
VHYST  
DROOP  
OCP  
VSEN–LDO  
V
INHIBIT  
IOUTLO  
CORE  
IOUT  
SLOWST  
VID0  
VID1  
BIAS  
HISENSE  
HIGHDR  
VSEN–RR  
DSP  
V
I/O  
See Table 1  
See Table 1  
Data  
Data Bus  
LOSENSE/LOHIB  
BOOT  
+
VLDODRV  
VDRV  
ANAGND  
BOOTLO  
LOWDR  
PERIPHERAL  
DRVGND  
PwrPad  
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of  
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.  
PowerPAD is a trademark of Texas Instruments.  
Copyright 2000, Texas Instruments Incorporated  
PRODUCTION DATA information is current as of publication date.  
Products conform to specifications per the terms of Texas Instruments  
standard warranty. Production processing does not necessarily include  
testing of all parameters.  
1
POST OFFICE BOX 655303 DALLAS, TEXAS 75265  
TPS56302  
DUAL-OUTPUT LOW-INPUT-VOLTAGE  
DSP POWER SUPPLY CONTROLLER WITH SEQUENCING  
SLVS289A MARCH 2000 REVISED OCTOBER 2000  
description (continued)  
To promote better system reliability during power up, voltage sequencing and protection are controlled such that  
the core and I/O power up together with the same slow-start voltage. At power down, the LDO and ripple  
regulator are discharged towards ground for added protection. The TPS56302 also includes inhibit, slow-start,  
and under-voltage lockout features to aide in controlling power sequencing. A tri-level voltage identification  
definition (VID) sets both regulated voltages to any of 9 preset voltage pairs from 1.3 V to 3.3 V. Other voltages  
are possible by implementing an external voltage divider. Strong MOSFET drivers, with a typical peak current  
rating of 2-A sink and source are included on chip, which allows paralleling MOSFETs to be driven and allowing  
highercurrenttobecontrolled. Thehigh-sidedriverfeaturesafloatingbootstrapdriverwithaninternalbootstrap  
synchronous rectifier. Many protection features are incorporated within the device to ensure better system  
integrity. An open-drain output power good status circuit monitors both output voltages, and is pulled low if either  
output falls below the threshold. An over current shutdown circuit protects the high-side power MOSFET against  
short-to-ground faults, while over voltage protection turns off the output drivers and LDO controller if either  
output exceeds its threshold. Under voltage protection turns off the high-side and low-side MOSFET drivers and  
the LDO controller if either output is 25% below V  
. Lossless current-sensing is implemented by detecting  
REF  
the drain-source voltage drop across the high-side power MOSFET while it is conducting. The TPS56302 is fully  
compliant with TI DSP power requirements.  
AVAILABLE OPTIONS  
PACKAGES  
T
J
EVALUATION MODULE  
TSSOP  
(PWP)  
40°C to 125°C  
TPS56302PWP  
TPS56302EVM163 (SLVP163)  
The PWP package is also available taped and reel. To order, add an R to the end of  
the part number (e.g., TPS56302PWPR).  
#  
Table 1. Voltage Identification Code  
VID TERMINALS  
56302  
56300  
#
#
#
#
V
V
V
V
REFLDO  
REFLDO  
(VDC)  
REFRR  
(VDC)  
REFRR  
(VDC)  
VID1  
VID0  
(VDC)  
0
0
0
1
1
1
2
2
2
0
1
2
0
1
2
0
1
2
1.30  
1.50  
1.30  
1.80  
1.30  
2.50  
1.30  
1.50  
1.80  
1.50  
1.80  
1.80  
3.30  
1.30  
3.30  
2.50  
3.30  
2.50  
1.30  
1.50  
1.30  
1.80  
1.30  
2.50  
1.30  
1.50  
1.80  
1.50  
1.80  
1.80  
3.30  
1.30  
3.30  
2.50  
3.30  
2.50  
§
0 = ground (GND), 1 = floating(V  
RR = Ripple Regulator, LDO = Low Drop-Out Regulator  
/2), 2 = (V  
)
BIAS  
BIAS  
V
/2 is internal, leave the VID pin floating. Adding an external 0.1-µF capacitor to ANAGND may be used  
BIAS  
to avoid erroneous level.  
#
External resistors may be used as a voltage divider (from V  
voltages to other values.  
to VSENxx to ground) to program output  
OUT  
2
POST OFFICE BOX 655303 DALLAS, TEXAS 75265  
TPS56302  
DUAL-OUTPUT LOW-INPUT-VOLTAGE  
DSP POWER SUPPLY CONTROLLER WITH SEQUENCING  
SLVS289A MARCH 2000 REVISED OCTOBER 2000  
functional block diagram  
LOSENSE/  
LOHIB  
IOUTLO  
HISENSE  
IOUT  
PWRGD  
25  
19  
21  
20  
26  
+
8
9
Bias  
>0.93xVSENRR  
>0.93xVSENLDO  
Reg.  
VDRV  
VLDODRV  
22  
SHUTDOWN  
INHIBIT  
VDRV UVLO  
Delay  
V
UVLO  
CC  
INHIBIT  
11  
10  
V
HIGHDR  
CC  
RR_OVP  
LDO_OVP  
RR_UVP *  
Fault  
Latch  
CPC1  
CPC2  
Q
R
S
LDO_UVP *  
BOOT  
12  
SHUTDOWN  
27  
24  
23  
OCP  
VDRV  
+
125 mV  
5 V  
13  
VDRV  
VSENLDO  
NGATELDO  
SHUTDOWN  
VLDODRV  
E/A  
1
2
VID0  
VID1  
SLOWST  
VREF_LDO  
VID  
+
(see Table 1)  
SHUTDOWN  
Vbias  
Hysteresis  
SLOWST  
17  
18  
16  
15  
BOOT  
Comparator  
Ivrefb/5  
VREF_RR  
SLOWST  
Adaptive  
Deadtime  
3
+
HIGHDR  
BOOTLO  
SHUTDOWN  
Hysteresis  
Setting  
VDRV  
SHUTDOWN  
LOWDR  
7
5
4
28  
6
14  
ANAGND  
VREFB  
VHYST DROOP  
VSENRR  
DRVGND  
* UVP is disabled during slowstart  
FET  
Synchronous  
RRRipple Regulator  
3
POST OFFICE BOX 655303 DALLAS, TEXAS 75265  
TPS56302  
DUAL-OUTPUT LOW-INPUT-VOLTAGE  
DSP POWER SUPPLY CONTROLLER WITH SEQUENCING  
SLVS289A MARCH 2000 REVISED OCTOBER 2000  
Terminal Functions  
TERMINAL  
DESCRIPTION  
NAME  
NO.  
VID0  
1
Voltage identification input 0. The VID pins are tri-level programming pins that set the output voltages for both  
converters. The code pattern for setting the output voltage is located in table 1. The VID pins are internally pulled to  
V /2, allowing floating voltage set to logic 1 (see Table 1).  
BIAS  
VID1  
2
3
Voltage identification input 1 (see VID0 pin description and Table 1).  
SLOWST  
Slow-start(softstart).Acapacitorfrompin3toGNDsetstheslow-starttimeforV  
will ramp-up together while tracking the slow-start voltage.  
andV .Bothsupplies  
OUT-LDO  
OUT-RR  
VHYST  
4
5
6
Hysteresis set pin. The hysteresis equals 2 × (VREFB VHYST).  
VREFB  
Buffered ripple regulator reference voltage from VID network.  
VSEN-RR  
Ripple regulator voltage sense input. This pin is connected to the ripple regulator output. It is used to sense the ripple  
regulator voltage for regulation, OVP, UVP, and power good functions. It is recommended that an RC low pass filter be  
connected at this pin to filter high frequency noise.  
ANAGND  
BIAS  
7
8
9
Analog ground  
Analog BIAS pin. Recommended that a 1-µF capacitor be connected to ANAGND.  
VLDODRV  
Output of charge pump generated through bootstrap diode. Approximately equal to VDRV + V 300 mV. Used as  
supply for LDO driver and bias regulator. Recommended that a 1-µF capacitor be connected to DRVGND.  
IN  
CPC1  
10  
11  
Connect one end of charge pump capacitor. Recommended that a 1-µF capacitor be connected from CPC1 to CPC2.  
V
CC  
3.3 V or 5 V supply (2.8 V 5.5 V). It is recommended that a low ESR capacitor be connected directly from V  
to  
CC  
DRVGND (bulk capacitors supplied at power stage input).  
CPC2  
VDRV  
12  
13  
Other end of charge pump capacitor from CPC1.  
Regulated output of internal charge pump. Supplies DRIVE charge for the low-side MOSFET driver (5 V).  
Recommended that a 10-µF capacitor be connected to DRVGND.  
DRVGND  
LOWDR  
BOOTLO  
BOOT  
14  
15  
16  
17  
18  
19  
Drive ground. Ground for FET drivers. Connect to source of low-side FET.  
Low drive. Output drive to synchronous rectifier low-side FET.  
Bootstrap low. This pin connects to the junction of the high-side and low-side FETs.  
Bootstrap pin. Connect a 1-µF low ESR capacitor to BOOTLO to generate floating drive for the high-side FET driver.  
High drive. Output drive to high-side power switching FETs  
HIGHDR  
LOSENSE/  
LOHIB  
Low sense/low-side inhibit. This pin is connected to the junction of the high and low-side FETs and is used in current  
sensing and the anti-cross-conduction to eliminate shoot-through current.  
HISENSE  
IOUTLO  
INHIBIT  
20  
21  
22  
High current sense. For current sensing across high-side FETs, connect to the drain of the high-side FETs.  
Current sense low output. Voltage on this pin is the voltage on the LOSENSE pin when the high-side FETs are on.  
This pin inhibits the drive signals to the MOSFET drivers. The IC is in a low-current state if INHIBIT is grounded. It is  
recommended that an external pullup resistor be connected to 5 V.  
NGATE-LDO  
23  
24  
Drives external N-channel power MOSFET to regulate LDO voltage to VREF-LDO.  
VSENLDO  
LDO voltage sense. This pin is connected to the LDO output. It is used to sense the LDO voltage for regulation, OVP,  
UVP, and power good functions.  
PWRGD  
IOUT  
25  
26  
Power good. Power good signal goes high when output voltage is above 93% of V  
LDO. This is an open-drain output.  
for both ripple regulator and  
REF  
Current signal output. Output voltage on this pin is proportional to the load current as measured across the high-side  
FETs on-resistance. The voltage on this pin equals 2 × R  
high-side FETs  
× IOUT, where R is the equivalent on-resistance of the  
ON  
ON  
OCP  
27  
28  
Overcurrentprotection. CurrentlimittrippointforrippleregulatorissetwitharesistordividerbetweentheIOUTpinand  
ANAGND. The trip point is typically 125 mV.  
DROOP  
Droopvoltage.Voltageinputusedtosettheamountofoutputvoltagedroopasafunctionofloadcurrent.Theamountof  
droop compensation is set with a resistor divider between the IOUT pin and ANAGND.  
4
POST OFFICE BOX 655303 DALLAS, TEXAS 75265  
TPS56302  
DUAL-OUTPUT LOW-INPUT-VOLTAGE  
DSP POWER SUPPLY CONTROLLER WITH SEQUENCING  
SLVS289A MARCH 2000 REVISED OCTOBER 2000  
absolute maximum ratings over operating virtual junction temperature (unless otherwise noted)  
Supply voltage range, V  
(see Note1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.3 V to 6 V  
CC  
Input voltage range: VDRV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.3 V to 7 V  
BOOT to DRVGND (High-side Driver ON) . . . . . . . . . . . . . . . . . . . . . . . . . 0.3 V to 15 V  
BOOT to BOOTLO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.3 V to 7 V  
BOOT to HIGHDRV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.3 V to 7 V  
BOOTLO to DRVGND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.5 V to 15 V  
DRV to DRVGND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.3 V to 7 V  
BIAS to ANAGND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.3 V to 7 V  
INHIBIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.3 V to 7 V  
DROOP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.3 V to V  
+ 0.3 V  
CC  
OCP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.3 V to 7 V  
VID0, VID1 (tri-level terminals) . . . . . . . . . . . . . . . . . . . . . . . . . . 0.3 V to V + 0.3 V  
BIAS  
PWRGD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.3 V to 6 V  
LOSENSE, LOHIB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.5 V to 14 V  
IOUTLO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.3 V to 14 V  
HISENSE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.3 V to 7 V  
VSENLDO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.3 V to 6 V  
VSENRR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.3 V to 6 V  
Voltage difference between ANAGND and DRVGND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±300 mV  
Continuous total power dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . See Dissipation Rating Table  
Operating junction temperature range, T . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40°C to 125°C  
J
Storage temperature range, T  
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65°C to 150°C  
stg  
Lead temperature soldering 1,6 mm (1/16 inch) from case for 10 seconds . . . . . . . . . . . . . . . . . . . . . . . 300°C  
Stresses beyond those listed under absolute maximum ratingsmay cause permanent damage to the device. These are stress ratings only, and  
functional operation of the device at these or any other conditions beyond those indicated under recommended operating conditionsis not  
implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.  
NOTE 1: Unless otherwise specified, all voltages are with respect to ANAGND.  
DISSIPATION RATING TABLE  
PWP  
T
A
< 25°C  
DERATING FACTOR  
0.0358 W/°C  
T
A
= 70°C  
T = 85°C  
A
PowerPAD mounted  
PowerPAD unmounted  
3.58 W  
1.78 W  
1.96 W  
0.98 W  
1.43 W  
0.71 W  
0.0178 W/°C  
Test Board Conditions:  
1.. Thickness: 0.062”  
2. 3× 3”  
3. 2 oz. Copper traces located on the top of the board (0.071 mm thick )  
4. Copper areas located on the top and bottom of the PCB for soldering  
5. Power and ground planes, 1 oz. Copper (0.036 mm thick)  
6. Thermal vias, 0.33 mm diameter, 1.5 mm pitch  
7. Thermal isolation of power plane  
For more information, refer to TI technical brief SLMA002.  
JUNCTION-CASE THERMAL RESISTANCE TABLE  
Junction-case thermal resistance  
0.72 °C/W  
5
POST OFFICE BOX 655303 DALLAS, TEXAS 75265  
TPS56302  
DUAL-OUTPUT LOW-INPUT-VOLTAGE  
DSP POWER SUPPLY CONTROLLER WITH SEQUENCING  
SLVS289A MARCH 2000 REVISED OCTOBER 2000  
electrical characteristics T = 0° to 125°C, V  
= 2.8 V to 5.5 V (unless otherwise noted)  
CC  
J
input  
PARAMETER  
TEST CONDITIONS  
MIN  
TYP  
MAX UNITS  
V
Supply voltage range  
Quiescent current  
2.8  
5.5  
V
CC  
I
INHIBIT = 0 V,  
V
= 5 V  
CC  
15  
mA  
CC  
NOTE 2: Ensured by design, not production tested.  
reference/voltage identification  
PARAMETER  
TEST CONDITIONS  
MIN  
0.3 V  
TYP  
MAX  
UNITS  
VID0VID1 High-level input voltage (2)  
V
V
BIAS  
V
V
BIAS  
2
BIAS  
2
VID0VID1 Mid-level floating voltage (1)  
V
1
1
VID0VID1 Low-level input voltage (0)  
0.3  
95  
V
Input pull-to-mid resistance  
36.5  
73  
kΩ  
cumulative reference  
PARAMETER  
TEST CONDITIONS  
MIN  
TYP  
MAX UNITS  
V
= 1.3 V,  
Hysteresis window = 30 mV,  
REF  
T = 25°C  
1.3% 0.25% 1.3%  
0.2%  
J
V
= 1.3 V,  
Hysteresis window = 30 mV,  
See Note 2  
REF  
T = 40°C,  
Cumulative accuracy ripple regulator  
J
V
= full range,  
Hysteresis window = 30 mV,  
See Note 2  
REF  
Droop = 0,  
1.5%  
2%  
1.5%  
2%  
V
= 1.3 V,  
I
O
= 0.1 A,  
REF  
Closed Loop,  
T = 25°C,  
Pass device = IRFZ24N,  
See Note 2  
J
Cumulative accuracy LDO  
V
= full range,  
I
= 0.1 A,  
Closed Loop,  
See Note 2  
REF  
Pass device = IRFZ24N,  
O
2.5%  
2.5%  
NOTE 2. Ensured by design, not production tested.  
buffered reference  
PARAMETER  
CONDITIONS  
MIN  
TYP  
MAX  
UNITS  
V
V
REF  
V
REF  
+1.5%  
I
I
=50 µA,  
=50 µA,  
Accuracy from V  
nominal  
nominal  
V
REF  
REFB  
REF  
REF  
1.5%  
VREFB output voltage  
VREFB load regulation  
Accuracy from V  
See Note 2  
REFB  
J
V
0.6%  
REF  
T = 40°C,  
10 µA < I  
< 500 µA  
2
mV  
REFB  
NOTE 2. Ensured by design, not production tested.  
hysteretic comparator(ripreg)  
PARAMETER  
TEST CONDITIONS  
MIN  
TYP  
MAX UNITS  
Input bias current  
See Note 2  
V  
500  
nA  
V
= 15 mV,  
VHYST  
VREFB  
Hysteresis window = 30 mV  
Hysteresis accuracy  
3.5  
3.5  
mV  
V
V = 30 mV,  
VREFB  
See Note 2  
VHYST  
Maximum hysteresis setting  
60  
mV  
Propagation delay time from VSENSE to HIGHDR or 10 mV overdrive, 1.3 V <= V  
<= 3.3 V,  
REF  
150  
5
250  
ns  
LOWDR (excluding deadtime)  
See Note 2  
Prefilter pole frequency  
See Note 2  
MHz  
NOTE 2. Ensured by design, not production tested.  
6
POST OFFICE BOX 655303 DALLAS, TEXAS 75265  
TPS56302  
DUAL-OUTPUT LOW-INPUT-VOLTAGE  
DSP POWER SUPPLY CONTROLLER WITH SEQUENCING  
SLVS289A MARCH 2000 REVISED OCTOBER 2000  
electrical characteristics T = 0° to 125°C, V  
= 2.8 V to 5.5 V (unless otherwise noted) (continued)  
CC  
J
overvoltage protection  
PARAMETER  
TEST CONDITIONS  
Upper threshold  
MIN  
TYP  
MAX UNITS  
120 %V  
OVP ripple regulator trip point (RR)  
112  
115  
REF  
mV  
Upper threshold lower threshold,  
(see Note 2)  
Hysteresis (RR)  
10  
1
Comparator propagation delay time (RR)  
V
= 30 mV,  
= 30 mV,  
See Note 2  
See Note 2  
µs  
µs  
overdrive  
Deglitch time (includes comparator propagation delay time) (RR)  
OVP LDO trip point (LDO)  
V
2.25  
112  
11  
overdrive  
Upper threshold  
115  
10  
1
120 %V  
REF  
mV  
Upper threshold lower threshold,  
(see Note 2)  
Hysteresis (LDO)  
Comparator propagation delay time (LDO)  
V
= 50 mV,  
= 50 mV,  
See Note 2  
See Note 2  
µs  
µs  
overdrive  
Deglitch time (includes comparator propagation delay time)  
(LDO)  
V
2.25  
11  
overdrive  
NOTE 2. Ensured by design, not production tested.  
undervoltage protection  
PARAMETER  
CONDITIONS  
MIN  
TYP  
MAX UNITS  
80 %V  
UVP ripple regulator trip point (RR)  
Lower threshold  
70  
75  
REF  
mV  
Upper threshold lower threshold,  
(see Note 2)  
Hysteresis (RR)  
10  
1
Comparator propagation delay time (RR)  
V
= 50 mV,  
= 50 mV,  
See Note 2  
See Note 2  
µs  
overdrive  
Deglitch time (includes comparator  
propagation delay time) (RR)  
V
0.1  
70  
1
ms  
overdrive  
UVP LDO trip point (LDO)  
Hysteresis (LDO)  
Lower threshold  
75  
10  
1
80 %V  
REF  
Upper threshold lower threshold,  
(see Note 2)  
mV  
Comparator propagation delay time (LDO)  
V
= 50 mV,See Note 2  
= 50 mV,See Note 2  
µs  
overdrive  
Deglitch time (includes comparator  
propagation delay time) (LDO)  
V
0.1  
1
ms  
overdrive  
NOTE 2. Ensured by design, not production tested.  
inhibit comparator  
PARAMETER  
CONDITIONS  
MIN  
TYP  
2.1  
MAX UNITS  
2.35  
V
Start threshold  
T = 40°C,  
J
See Note 2  
2.1  
Stop threshold  
1.79  
V
NOTE 2. Ensured by design, not production tested.  
VDRV UVLO  
PARAMETER  
CONDITIONS  
MIN  
TYP  
MAX UNITS  
Start threshold  
Hysteresis  
See Note 2  
4.9  
V
V
V
See Note 2  
See Note 2  
0.3  
4.4  
0.35  
Stop threshold  
NOTE 2. Ensured by design, not production tested.  
7
POST OFFICE BOX 655303 DALLAS, TEXAS 75265  
TPS56302  
DUAL-OUTPUT LOW-INPUT-VOLTAGE  
DSP POWER SUPPLY CONTROLLER WITH SEQUENCING  
SLVS289A MARCH 2000 REVISED OCTOBER 2000  
electrical characteristics T = 0° to 125°C, V  
= 2.8 V to 5.5 V (unless otherwise noted) (continued)  
CC  
J
slow-start  
PARAMETER  
CONDITIONS  
MIN  
10.4  
3
TYP  
MAX UNITS  
V
= 0.5 V,  
(S/S)  
Resistance from VREFB pin to ANAGND = 20 kΩ  
VREFB = 1.3 V, Ichg = (I /5)  
Charge current  
13  
15.6  
µA  
VREFB  
= 1.3 V  
Discharge current  
V
(S/S)  
mA  
mV  
nA  
Comparator input offset voltage  
Comparator input bias current  
Hysteresis accuracy  
10  
100  
See Note 2  
10  
7.5  
7.5  
mV  
ns  
Comparator propagation delay  
Overdrive = 10 mV,  
See Note 2  
560  
1000  
NOTE 2. Ensured by design, not production tested.  
V
UVLO  
CC  
PARAMETER  
CONDITIONS  
MIN  
TYP  
2.72  
2.71  
MAX UNITS  
(see Note 2)  
2.80  
V
Start threshold  
T = 40°C,  
J
See Note 2  
Stop threshold  
(see Note 2)  
2.48  
V
NOTE 2. Ensured by design, not production tested.  
power good  
PARAMETER  
CONDITIONS  
and VDRV above UVLO thresholds  
MIN  
TYP  
93  
MAX UNITS  
V
90  
95  
Undervoltage trip point ripple regulator  
(VSENSERR)  
IN  
T = 40°C,  
%V  
REF  
REF  
See Note 2  
and VDRV above UVLO thresholds  
93  
J
V
90  
93  
95  
Undervoltage trip point LDO  
(VSENSELDO)  
IN  
T = 40°C,  
%V  
See Note 2  
93  
J
Output saturation voltage  
Leakage current  
I
=5 mA  
0.5  
1
0.75  
V
O
V
V
V
= 4.5 V  
µA  
mV  
mV  
PGD  
REF  
REF  
= 1.3 V, 1.5 V, or 1.8 V  
= 2.5 V, or 3.3 V  
50  
75  
Hysteresis  
100  
125  
Comparator high-low transition time  
(propagation delay only)  
See Note 2  
1
1
µs  
Comparator low-high transition time  
(propagation delay + deglitch)  
See Note 2  
0.2  
2
ms  
NOTE 2. Ensured by design, not production tested.  
droop compensation  
PARAMETER  
CONDITIONS  
MIN  
TYP  
MAX UNITS  
54 mV  
Initial accuracy  
V
= 50 mV  
46  
DROOP  
overcurrent protection (RR)  
PARAMETER  
OCP trip point  
CONDITIONS  
MIN  
TYP  
MAX UNITS  
118  
130  
142  
300  
mV  
nA  
µs  
Input bias current  
Comparator propagation delay time  
V
= 30 mV,  
= 30 mV,  
See Note 2  
See Note 2  
1
overdrive  
Deglitch time (includes comparator  
propagation delay time)  
V
2.25  
11  
µs  
overdrive  
NOTE 2. Ensured by design, not production tested.  
8
POST OFFICE BOX 655303 DALLAS, TEXAS 75265  
TPS56302  
DUAL-OUTPUT LOW-INPUT-VOLTAGE  
DSP POWER SUPPLY CONTROLLER WITH SEQUENCING  
SLVS289A MARCH 2000 REVISED OCTOBER 2000  
electrical characteristics T = 0° to 125°C, V  
= 2.8 V to 5.5 V (unless otherwise noted) (continued)  
CC  
J
high-side VDS sensing  
PARAMETER  
CONDITIONS  
MIN  
TYP  
MAX UNITS  
Gain  
2
V/V  
V
= 3.3 V,  
V
= 3.2 V,  
HISENSE  
Differential input to Vds sensing amp = 100 mV  
IOUTLO  
Initial accuracy  
194  
69  
208  
250  
mV  
V
V
=2.8 V to 5.5 V,  
V  
HISENSE  
HISENSE IOUTLO  
Common-mode rejection ratio  
Sink current (IOUTLO)  
75  
dB  
nA  
µA  
=100 mV  
2.8 V < V  
IOUTLO  
< 5.5 V  
V
V
= 0.5 V,  
=2.8 V  
V
V
=3.3 V,  
IOUT  
IOUTLO  
HISENSE  
Source current (IOUT)  
500  
50  
V
V
= 0.05 V,  
=3.3 V  
=3.35 V,  
IOUT  
IOUTLO  
HISENSE  
Sink current (IOUT)  
Output voltage swing  
µA  
V
V
V
V
V
V
V
V
V
V
V
V
V
=5.5 V,  
=4.5 V,  
=3 V,  
R
R
R
= 10 kΩ  
0
0
1.75  
1.5  
HISENSE  
HISENSE  
HISENSE  
HISENSE  
HISENSE  
HISENSE  
HISENSE  
HISENSE  
HISENSE  
HISENSE =  
HISENSE =  
HISENSE =  
HISENSE =  
IOUT  
IOUT  
IOUT  
= 10 kΩ  
= 10 kΩ  
V
0
0.75  
LOSENSE high-level input voltage  
LOSENSE low-level input voltage  
LOSENSE high-level input voltage  
LOSENSE low-level input voltage  
LOSENSE high-level input voltage  
LOSENSE low-level input voltage  
=2.8 V,  
=2.8 V,  
=4.5 V,  
=4.5 V,  
=5.5 V,  
=5.5 V,  
See Note 2  
See Note 2  
See Note 2  
See Note 2  
See Note 2  
See Note 2  
See Note 2  
See Note 2  
See Note 2  
See Note 2  
1.77  
V
V
V
V
V
V
1.49  
2.4  
2.85  
3.80  
3.2  
90  
6 V,  
70  
80  
4.5 V,  
3.6 V,  
2.8 V,  
100  
120  
180  
Sample/hold resistance  
90  
120  
V
V
= 2.55 V,  
HISENSE  
pulsed from 2.55 V to 2.45 V,  
4
3.5  
3
IOUTLO  
100 ns rise and fall times,  
See Note 2  
V
V
= 2.8 V,  
HISENSE  
pulsed from 2.8 V to 2.7 V,  
IOUTLO  
100 ns rise and fall times,  
See Note 2  
Response time (measured from 90% of  
µs  
V
to 90% of V  
)
IOUTLO  
IOUT  
V
V
= 4.5 V,  
HISENSE  
pulsed from 4.5 V to 4.4 V,  
IOUTLO  
100 ns rise and fall times,  
See Note 2  
V
V
= 5.5 V,  
HISENSE  
pulsed from 5.5 V to 5.9 V,  
3
IOUTLO  
100 ns rise and fall times,  
See Note 2  
Short circuit protection rising edge delay  
Sample/hold switch turnon/turnoff delay  
LOSENSE grounded,  
See Note 2  
300  
30  
500  
100  
ns  
ns  
2.8 V < V  
HISENSE  
< 5.5 V,  
V
= V  
,
See Note 2  
LOSENSE  
HISENSE  
NOTE 2. Ensured by design, not production tested.  
9
POST OFFICE BOX 655303 DALLAS, TEXAS 75265  
TPS56302  
DUAL-OUTPUT LOW-INPUT-VOLTAGE  
DSP POWER SUPPLY CONTROLLER WITH SEQUENCING  
SLVS289A MARCH 2000 REVISED OCTOBER 2000  
electrical characteristics T = 0° to 125°C, V  
= 2.8 V to 5.5 V (unless otherwise noted) (continued)  
CC  
J
thermal shutdown  
PARAMETER  
CONDITIONS  
MIN  
TYP  
145  
10  
MAX UNITS  
Over temperature trip point  
Hysteresis  
See Note 2  
See Note 2  
°C  
°C  
NOTE 2. Ensured by design, not production tested.  
synch charge pump regulator  
PARAMETER  
CONDITIONS  
MIN  
200  
TYP  
300  
5.2  
MAX UNITS  
2.8 V < V < 5.5 V,  
VDRV=5 V ,  
I
= 50 mA,  
IN  
DRV  
Internal oscillator frequency  
400  
kHz  
See Note 2  
See Note 2  
See Note 2  
Internal oscillator turnon threshold  
Internal oscillator turnon hysteresis  
V
V
above UVLO threshold,  
5.05  
V
CC  
above UVLO threshold,  
20  
mV  
CC  
NOTE 2. Ensured by design, not production tested.  
hysteretic comparator (charge pump)  
PARAMETER  
CONDITIONS  
above UVLO threshold,  
MIN  
TYP  
MAX UNITS  
Threshold  
Hysteresis  
V
See Note 2  
See Note 2  
5.05  
5.2  
V
IN  
IN  
V
above UVLO threshold,  
20  
mV  
NOTE 2. Ensured by design, not production tested.  
deadtime circuit  
PARAMETER  
CONDITIONS  
MIN  
TYP MAX UNITS  
LOSENSE/LOHIB high level input voltage  
LOSENSE/LOHIB low level input voltage  
LOWDR high-level input voltage  
V
V
V
V
=2.55 V 5.5 V, See Note 2  
=2.55 V 5.5 V, See Note 2  
2.4  
V
HISENSE  
HISENSE  
HISENSE  
HISENSE  
1.33  
V
V
V
=2.55 V5.5 V,  
=2.55 V5.5 V,  
See Note 2  
See Note 2  
3
LOWDR low-level input voltage  
1.7  
C
= 9 nF, 10% threshold on LOWDR,  
LOWDR  
VDRV=5 V  
Driver nonoverlap time  
40  
170  
ns  
NOTE 2. Ensured by design, not production tested.  
10  
POST OFFICE BOX 655303 DALLAS, TEXAS 75265  
TPS56302  
DUAL-OUTPUT LOW-INPUT-VOLTAGE  
DSP POWER SUPPLY CONTROLLER WITH SEQUENCING  
SLVS289A MARCH 2000 REVISED OCTOBER 2000  
electrical characteristics T = 0° to 125°C, V  
= 2.8 V to 5.5 V (unless otherwise noted) (continued)  
J
CC  
output drivers (see Note 5)  
PARAMETER  
CONDITIONS  
< 100 us,  
MIN  
TYP  
MAX UNITS  
Duty cycle < 2%,  
t
pw  
V
V
V  
= 4.5 V,  
0.7  
2
BOOT  
BOOTLO  
= 4 V (sink),  
See Note 2 and Figure 15  
< 100 us,  
HIGHDR  
Duty cycle < 2%,  
t
pw  
V
V
V  
= 4.5 V,  
1.2  
1.3  
1.4  
2
2
2
BOOT  
BOOTLO  
= 0.5 V (source), See Note 2 and Figure 15  
HIGHDR  
Peak output current  
A
Duty cycle < 2%,  
= 4.5 V,  
t
V
< 100 µs,  
pw  
V
DRV  
= 4 V (sink),  
LOWDR  
See Note 2 and Figure 15  
Duty cycle < 2%,  
t
V
< 100 us,  
pw  
V
= 4.5 V,  
= 0.5 V (source),  
DRV  
See Note 2 and Figure 15  
LOWDR  
HIGHDR  
HIGHDR  
V
V  
= 4.5 V, V  
= 0.5 V,  
= 4 V,  
BOOT  
BOOTLO  
V  
BOOTLO  
5
See Note 2  
V
= 4.5 V, V  
BOOT  
See Note 2  
45  
Output resistance  
V
V
= 4.5 V,  
V
V
V
= 0.5 V, See Note 2  
9
DRV  
LOWDR  
= 4.5 V,  
= 4 V,  
See Note 2  
45  
DRV  
LOWDR  
C
= 3.3 nF,  
= 4.5 V,  
L
BOOT  
HIGHDR rise/fall time  
LOWDR rise/fall time  
60  
40  
10  
ns  
ns  
µA  
V
=grounded,  
See Note 2  
See Note 2  
BOOTLO  
C
= 3.3 nF,  
V
DRV  
= 4.5 V,  
L
INHIBIT grounded,  
BOOTLO grounded  
V
IN  
< UVLO, V  
=6 V,  
BOOT  
INHIBIT connected to +5 V,  
= 200 kHz,  
BOOTLO = 0,  
See Note 2  
V
V
C
> UVLO  
= 5.5 V,  
= 50 pF,  
HIGHDR  
IN  
BOOT  
High-side driver quiescent current  
f
(swx)  
2
mA  
NOTES: 2. Ensured by design, not production tested.  
5. The pullup/pulldown circuits of the drivers are bipolar and MOSFET transistors in parallel. The peak output current rating is the  
combined current from the bipolar and MOSFET transistors. The output resistance is the R  
the voltage on the driver output is less than the saturation voltage of the bipolar transistor.  
of the MOSFET transistor when  
ds(on)  
LDO N-channel output driver  
PARAMETER  
CONDITIONS  
MIN  
TYP  
MAX UNITS  
V
V
= 7.5 V,  
= 0.9 × V  
V
= 3 V (source),  
LDODRV  
IOSENSE  
NDRV  
See Note 2  
100  
1.5  
µA  
,
LDOREF  
Peak output current  
V
V
= 7.5 V,  
= 1.1 × V  
V
=0 V (sink),  
LDODRV  
IOSENSE  
NDRV  
mA  
,
See Note 2  
LDOREF  
Open loop voltage gain  
7.5 V V  
See Note 2  
0.5 V,  
V
IN  
= 5.5 V,  
3000  
(70)  
V/V  
(dB)  
NGATELDO  
(V  
/ V  
)
NGATELDO SENSELDO  
f = 1 kHz,  
C
=10 µF,  
O
5.5 V V 2.55 V,  
T =125 °C,  
J
Power supply ripple rejection  
60  
dB  
IN  
See Note 2  
NOTE 2. Ensured by design, not production tested.  
11  
POST OFFICE BOX 655303 DALLAS, TEXAS 75265  
TPS56302  
DUAL-OUTPUT LOW-INPUT-VOLTAGE  
DSP POWER SUPPLY CONTROLLER WITH SEQUENCING  
SLVS289A MARCH 2000 REVISED OCTOBER 2000  
electrical characteristics T = 0° to 125°C, V  
= 2.8 V to 5.5 V (unless otherwise noted) (continued)  
CC  
J
V
and V  
discharge  
SENSERR  
SENSELDO  
PARAMETER  
CONDITIONS  
= 1.5 V, See Note 2  
= 5.5 V  
MIN  
TYP  
5
MAX UNITS  
V
discharge FET current saturation  
V
mA  
SENSERR  
SENSERR  
SENSERR  
SENSELDO  
SENSELDO  
SENSELDO  
SENSERR  
V
discharge series resistance (limits current)  
discharge FET propagation delay time  
INHIBIT = 0 V,  
See Note 2  
V
IN  
1
kΩ  
V
V
V
V
100  
100  
ns  
mA  
kΩ  
ns  
discharge FET current saturation  
V
= 3.3 V,  
See Note 2  
= 5.5 V,  
5
1
SENSELDO  
discharge series resistance (limits current)  
discharge FET propagation delay time  
INHIBIT = 0 V,  
See Note 2  
V
IN  
NOTE 2. Ensured by design, not production tested.  
detailed description  
reference/voltage identification  
The reference/voltage identification definition (VID) section consists of a temperature compensated bandgap  
reference and a 2-pin voltage selection network. Both ripple regulator and LDO reference voltages are  
programmedwitheachVIDsetting. The2VIDpinsareinputstotheVIDselectionnetworkandaretri-levelinputs  
that may be set to GND, floating (V  
/2), or V  
. The VID codes allow the controller to power both current  
BIAS  
BIAS  
and future DSP products. The output voltages may also be programmed by external resistor voltage dividers  
for any values not included in the VID code settings. Refer to Table 1 for the VID code settings. The output  
voltages of the VID network, V  
, is within 1.5% and V  
is within 2.5% of the nominal setting over  
REFRR  
REFLDO  
the VID range of 1.3 V to 3.3 V. The reference tolerance conditions include a junction temperature range of  
40 C to +125 C and a V supply voltage range of 2.8 V to 5.5 V. The V output of the reference/VID  
CC  
REFRR  
network is indirectly brought out through a buffer to the VREFB pin. The voltage on this pin will be within 1.5%  
ofV . ItisnotrecommendedtodriveloadswithVREFB, otherthansettingthehysteresisofthehysteretic  
REFRR  
comparator, becausethecurrentdrawnfromVREFBsetsthechargingcurrentfortheslow-startcapacitor. Refer  
to the slow-start section of this document for additional information.  
hysteretic comparator  
The hysteretic comparator regulates the output voltage of the synchronous-buck converter. The hysteresis is  
set by 2 external resistors and is centered around V  
. The two external resistors form a resistor divider from  
REF  
VREFB to ANAGND, and the divided down voltage connects to the VHYST pin. The hysteresis of the  
comparator will be equal to twice the voltage difference that is across the VREFB and VHYST pins. The  
propagation delay from the comparator inputs to the driver outputs is 250 ns maximum. The maximum  
hysteresis setting is 60 mV.  
low-side driver  
The low-side driver is designed to drive low r  
logic-level N-channel MOSFETs. The current rating of the  
DS(on)  
driver is 2-A typical, source and sink. The bias to the low-side driver is internally connected to the regulated  
synchronous charge pump output.  
high-side driver  
The high-side driver is designed to drive low r  
logic-level N-channel MOSFETs. The current rating of the  
DS(on)  
driver is 2 amps typical, source and sink. The high-side driver can be configured either as a floating bootstrap  
driver or as a ground-reference driver. When configured as a floating driver, the bias voltage to the driver is  
developed from the charge pump VDRV voltage. The internal synchronous bootstrap rectifier, connected  
between the VDRV and BOOT pins, is a synchronously-rectified MOSFET for improved drive efficiency. The  
maximum voltage that can be applied between the BOOT pin and ground is 14 V.  
12  
POST OFFICE BOX 655303 DALLAS, TEXAS 75265  
TPS56302  
DUAL-OUTPUT LOW-INPUT-VOLTAGE  
DSP POWER SUPPLY CONTROLLER WITH SEQUENCING  
SLVS289A MARCH 2000 REVISED OCTOBER 2000  
detailed description (continued)  
deadtime control  
Deadtime control prevents shoot-through current from flowing through the main power FETs during switching  
transitions by actively controlling the turnon time of the MOSFET drivers. The high-side driver is not allowed  
to turn on until the gate drive voltage to the low-side FET is below 1 V, and the low-side driver is not allowed  
to turn on until the voltage at the junction of the 2 FETs (Vphase) is below 2 V.  
current sensing  
Current sensing is achieved by sampling and holding the voltage across the high-side power FET while the  
high-side FET is on. The sampling network consists of an internal 60-switch and an external hold capacitor.  
Internal logic controls the turnon and turnoff of the sample/hold switch such that the switch does not turn on until  
the Vphase voltage transitions high, and the switch turns off when the input to the high-side driver goes low.  
Thus sampling will occur only when the high-side FET is conducting current. The voltage on the IOUT pin equals  
2 times the sensed high-side voltage.  
droop compensation  
The droop compensation network reduces the load transient overshoot / undershoot on V  
, relative to V  
REF  
OUT  
(see the application information section of this document for more details). V  
is programmed to a voltage  
OUT  
greater than V  
by an external resistor divider from V  
to the VSENSE pin to reduce the undershoot on  
REF  
OUT  
V
during a low to high load transient. The overshoot during a high to low load transient is reduced by  
OUT  
subtracting the voltage that is on the DROOP pin from V  
. The voltage on the IOUT pin is divided down with  
REF  
an external resistor divider, and connected to the DROOP pin.  
inhibit  
INHIBIT is a TTL-compatible comparator pin that is used to enable the controller. When INHIBIT is lower than  
the threshold, the output drivers are low and the slow-start capacitor is discharged. When INHIBIT goes high  
(above 2.1 V), the short across the slow-start capacitor is released and normal converter operation begins.  
When another system logic supply is connected to the INHIBIT pin, this pin controls power sequencing by  
locking out controller operation until the system logic supply exceeds the input threshold voltage of the inhibit  
circuit; thus the +3.3-V supply and another system logic supply (either +5 V or +12 V) must be above UVLO  
thresholds before the controller is allowed to start up. Toggling the INHIBIT pin from low to high or recycling V  
clears the fault latch.  
CC  
slow-start  
The slow-start circuit controls the rate at which both V  
and V  
power up (at the same time). A  
OUTRR  
OUTLDO  
capacitor is connected between the SLOWST and ANAGND pins and is charged by an internal current source.  
The value of the current source is proportional to the reference voltage, so that the charging rate of C  
SLOWST  
is proportional to the ripple regulator reference voltage. The slow-start charging current is determined by the  
following equation:  
I
VREFB  
I
SLOWSTART  
5
Where I  
is the current flowing out of the VREFB pin. It is recommended that no additional loads be  
VREFB  
connectedtoVREFB, otherthantheresistordividerforsettingthehysteresisvoltage. Thustheseresistorvalues  
will determine the slow-start charging current. The maximum current that can be sourced by the VREFB circuit  
is 500 µA. The equation for the slow-start time is:  
T
5
C
R
SLOWSTART  
SLOWSTART  
VREFB  
Where R  
is the total external resistance from VREFB to ANAGND.  
VREFB  
13  
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SLVS289A MARCH 2000 REVISED OCTOBER 2000  
detailed description (continued)  
V
and VDRV undervoltage lockout  
CC  
The V  
undervoltage lockout circuit disables the controller while the V  
supply is below the 2.8-V start  
CC  
CC  
threshold. The VDRV undervoltage lockout circuit disables the controller while the VDRV supply is below the  
4.9 V start threshold during powerup. While the controller is disabled, the output drivers will be low, the LDO  
drive is off, and the slow-start capacitor will be shorted. When V  
short across the slow-start capacitor is released and normal converter operation begins. Recycling V  
toggling the INHIBIT pin from low to high clears the fault latch.  
and VDRV exceed the start threshold, the  
CC  
or  
CC  
power good  
The power good circuit monitors for an undervoltage condition on V  
and V  
. The power good  
OUTRR  
OUTLDO  
(PWRGD) pin is pulled low if either V  
is 7% below V  
, or V  
is 7% below V  
.
OUTRR  
REFRR  
OUTLDO  
REFLDO  
PWRGD is an open drain output. The PWRGD pin is also pulled down, if either V  
UVLO thresholds.  
or VDRV are below their  
CC  
overvoltage protection  
The overvoltage protection circuit monitors V  
and V  
for an overvoltage condition. If V  
OUTRR  
OUTLDO OUTRR  
or V  
are 15% above their reference voltage, then a fault latch is set and both output drivers and LDO  
OUTLDO  
are turned off. The latch remains set until the V or inhibit voltages go below their undervoltage lockout turnoff  
CC  
values. A 1-µs to 5 µs deglitch timer is included for noise immunity.  
overcurrent protection  
The overcurrent protection circuit monitors the current through the high-side FET. The overcurrent threshold  
is adjustable with an external resistor divider between IOUT and ANAGND pins, with the divider voltage  
connected to the OCP pin. If the voltage on the OCP pin exceeds 125 mV, a fault latch is then set and the output  
drivers are turned off. The latch remains set until the V or inhibit voltages go below their undervoltage lockout  
CC  
values. A 1-µs to 5-µs deglitch timer is included for noise immunity. The OCP circuit is also designed to protect  
the high-side power FET against a short-to-ground fault on the terminal common to both power FETs.  
undervoltage protection  
TheundervoltageprotectioncircuitmonitorsV  
andV  
foranundervoltagecondition.IfV  
OUTRR  
OUTLDO OUTRR  
or V  
is 15% below their reference voltage, then a fault latch is set and both output drivers and LDO are  
OUTLDO  
turned off. The latch remains set until the V  
or inhibit voltages go below their undervoltage lockout values.  
CC  
A 100-µs to 1-ms deglitch timer is included for noise immunity.  
synchronous charge pump  
The regulated synchronous charge pump provides drive voltage to the low-side driver at VDRV (5 V), and to  
the high-side driver configured as a floating driver. The minimum drive voltage is 4.5 V, (typical is 5 V). The  
minimum short-circuit current is 80 mA. The bootstrap capacitor is used to provide voltage for the high-side FET,  
the power for VLDODRV, and the bias regulator. Instead of diodes, synchronous rectified MOSFETs are used  
to reduce voltage drop losses and allow a lower input voltage threshold. The charge pump oscillator operates  
at 300 kHz until the UVLO VDRV is set; after which it is synchronized to the converter switching frequency and  
is turned on and off to regulate VDRV at 5 V.  
The charge pump is designed to operate at a switching frequency of 200 kHz to 400 kHz. Operation at low  
frequency may require larger capacitors on the CPCx and VDRV pins. Higher frequencies (> 400 kHz) may not  
be possible.  
power sequence  
The V  
voltage is powered up with respect to the same slow-start reference voltage as the V  
OUTRR  
OUTLDO  
Also, at power down, the V  
series with 1-kresistors.  
and V  
are discharged to ground through P-channel MOSFETs in  
OUTRR  
OUTLDO  
14  
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TPS56302  
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DSP POWER SUPPLY CONTROLLER WITH SEQUENCING  
SLVS289A MARCH 2000 REVISED OCTOBER 2000  
TYPICAL CHARACTERISTICS  
QUIESCENT CURRENT  
vs  
V
UVLO HYSTERESIS  
vs  
CC  
JUNCTION TEMPERATURE  
JUNCTION TEMPERATURE  
13  
12  
11  
10  
180  
175  
170  
165  
160  
155  
150  
V
= 3.3 V  
CC  
INHIBIT = 0 V  
0
25  
50  
75  
100  
125  
0
25  
50  
75  
100  
125  
T
J
Junction Temperature °C  
T
J
Junction Temperature °C  
Figure 1  
Figure 2  
V
UVLO START THRESHOLD VOLTAGE  
SLOW-START CHARGE CURRENT  
vs  
CC  
vs  
JUNCTION TEMPERATURE  
JUNCTION TEMPERATURE  
2.750  
2.725  
2.700  
2.675  
2.65  
15  
14  
13  
12  
11  
10  
0
25  
50  
75  
100  
125  
0
25  
50  
75  
100  
125  
T
J
Junction Temperature °C  
T
J
Junction Temperature °C  
Figure 3  
Figure 4  
15  
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TPS56302  
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DSP POWER SUPPLY CONTROLLER WITH SEQUENCING  
SLVS289A MARCH 2000 REVISED OCTOBER 2000  
TYPICAL CHARACTERISTICS  
SLOW-START TIME  
vs  
SUPPLY CURRENT (VREFB)  
SLOW-START TIME  
vs  
SLOW-START CAPACITANCE  
1000  
100  
100  
10  
V
V
= 3.3 V  
= 1.3 V  
= 0.1 µF  
CC  
(VREFB)  
V
V
= 3.3 V  
CC  
= 1.3 V  
(VREFB)  
(VREFB)  
J
C
S
J
I
T
= 65 µA  
T
= 27°C  
= 25°C  
10  
1
1
0.1  
0.0001  
1
10  
100  
1000  
0.0010  
0.0100  
0.1000  
1
I
Supply Current (VREFB) µA  
CC  
Slow-start Capacitance µF  
Figure 5  
Figure 6  
DRIVER  
RISE TIME  
DRIVER  
FALL TIME  
vs  
vs  
GATE CAPACITANCE  
GATE CAPACITANCE  
1000  
100  
1000  
T
J
= 27°C  
T = 27°C  
J
100  
High Side  
High Side  
Low Side  
Low Side  
10  
10  
1
0.1  
1
0.1  
1
10  
100  
1
10  
100  
Gate Capacitance nF  
Gate Capacitance nF  
Figure 7  
Figure 8  
16  
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TPS56302  
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DSP POWER SUPPLY CONTROLLER WITH SEQUENCING  
SLVS289A MARCH 2000 REVISED OCTOBER 2000  
TYPICAL CHARACTERISTICS  
DRIVER  
DRIVER  
HIGH-SIDE OUTPUT RESISTANCE  
vs  
LOW-SIDE OUTPUT RESISTANCE  
vs  
JUNCTION TEMPERATURE  
JUNCTION TEMPERATURE  
5.0  
4.5  
4.0  
3.5  
3.0  
2.5  
2.0  
1.5  
1.0  
8
7
6
5
4
3
2
1
0
0
25  
50  
75  
100  
125  
0
25  
50  
75  
100  
125  
T
J
Junction Temperature °C  
T
J
Junction Temperature °C  
Figure 9  
Figure 10  
DRIVER  
CURRENT  
vs  
VDRV UVLO START THRESHOLD VOLTAGE  
vs  
JUNCTION TEMPERATURE  
OUTPUT VOLTAGE  
5
4.5  
4
4.70  
4.69  
4.68  
4.67  
4.66  
4.65  
3.5  
3
2.5  
2
2 A Typical  
1.5  
1
4.5 V  
0.5  
0
0
1
2
3
4
5
6
7
8
9
0
25  
50  
75  
100  
125  
V
O
Output Voltage V  
T
J
Junction Temperature °C  
Figure 11  
Figure 12  
17  
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TPS56302  
DUAL-OUTPUT LOW-INPUT-VOLTAGE  
DSP POWER SUPPLY CONTROLLER WITH SEQUENCING  
SLVS289A MARCH 2000 REVISED OCTOBER 2000  
TYPICAL CHARACTERISTICS  
RIPPLE REGULATOR  
POWER GOOD THRESHOLD  
vs  
VDRV UVLO HYSTERESIS  
vs  
JUNCTION TEMPERATURE  
JUNCTION TEMPERATURE  
300  
280  
260  
240  
220  
200  
180  
160  
140  
120  
100  
96  
95  
94  
93  
92  
91  
90  
89  
88  
0
25  
50  
75  
100  
125  
0
25  
50  
75  
100  
125  
T
J
Junction Temperature °C  
T
J
Junction Temperature °C  
Figure 13  
Figure 14  
INHIBIT START THRESHOLD VOLTAGE  
INHIBIT HYSTERESIS VOLTAGE  
vs  
vs  
JUNCTION TEMPERATURE  
JUNCTION TEMPERATURE  
2.100  
2.075  
2.050  
2.025  
2.000  
140  
130  
120  
110  
100  
90  
0
25  
50  
75  
100  
125  
0
25  
50  
75  
100  
125  
T
J
Junction Temperature °C  
T
J
Junction Temperature °C  
Figure 15  
Figure 16  
18  
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TPS56302  
DUAL-OUTPUT LOW-INPUT-VOLTAGE  
DSP POWER SUPPLY CONTROLLER WITH SEQUENCING  
SLVS289A MARCH 2000 REVISED OCTOBER 2000  
TYPICAL CHARACTERISTICS  
RIPPLE REGULATOR OVP THRESHOLD  
RIPPLE REGULATOR UVP THRESHOLD  
vs  
vs  
JUNCTION TEMPERATURE  
JUNCTION TEMPERATURE  
118  
117  
116  
115  
77  
76  
75  
74  
114  
113  
112  
73  
72  
71  
0
25  
50  
75  
100  
125  
0
25  
50  
75  
100  
125  
T
J
Junction Temperature °C  
T
J
Junction Temperature °C  
Figure 17  
Figure 18  
OCP THRESHOLD VOLTAGE  
vs  
JUNCTION TEMPERATURE  
135  
133  
131  
129  
0
25  
50  
75  
100  
125  
T
J
Junction Temperature °C  
Figure 19  
19  
POST OFFICE BOX 655303 DALLAS, TEXAS 75265  
TPS56302  
DUAL-OUTPUT LOW-INPUT-VOLTAGE  
DSP POWER SUPPLY CONTROLLER WITH SEQUENCING  
SLVS289A MARCH 2000 REVISED OCTOBER 2000  
TYPICAL CHARACTERISTICS  
LDO OVP THRESHOLD  
vs  
JUNCTION TEMPERATURE  
118  
117  
116  
115  
114  
113  
112  
0
25  
50  
75  
100  
125  
T
J
Junction Temperature °C  
Figure 20  
LDO UVP THRESHOLD  
vs  
JUNCTION TEMPERATURE  
77  
76  
75  
74  
73  
72  
71  
0
25  
50  
75  
100  
125  
T
J
Junction Temperature °C  
Figure 21  
20  
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TPS56302  
DUAL-OUTPUT LOW-INPUT-VOLTAGE  
DSP POWER SUPPLY CONTROLLER WITH SEQUENCING  
SLVS289A MARCH 2000 REVISED OCTOBER 2000  
APPLICATION INFORMATION  
evaluation module  
In many DSP applications, the voltage bus powering DSP I/O also has to power peripheral circuitry. The total  
current is much higher than the requirement for the I/O only. This is the reason to use the high-efficiency ripple  
regulator to power I/O. In turn, the core power is delivered by LDO output. Since the I/O voltage is lower than  
the input voltage in cases such as 5-V input, but higher than the core voltage, the ripple regulator output should  
be used as the input voltage for LDO to achieve higher efficiency. In EVM testing, J14 (RROUT) is connected  
to J21(VILDO). The test results displayed in this section are all based on this configuration.  
TP6  
FB2  
+
J2  
TP5  
+
JP3  
L1  
R17  
3.3 uH  
+
TP8  
TP7  
Q1:A  
J1  
Q4  
TP1  
TP11  
E1  
TP3  
U1  
TPS563xxPWP  
TP4  
TP2 Q1:B  
+
+
+
Q5  
+
TP10  
FB1  
JP1  
JP2  
When an output current greater than 4 A is desired on the ripple regulator, please add a 10 resistor (R17) between pin 18 and Q1:A.  
Because the EVM is configured for 4 A and below, R17 is 0 and is not included on the module.  
Figure 22. EVM Schematic  
Table 2. EVM Input and Outputs  
V
IN  
5 V  
I
V
RR  
3.3 V  
I
V
LDO  
1.8 V  
I
IN  
4 A  
RR  
4 A  
LDO  
0.5 A  
21  
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TPS56302  
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DSP POWER SUPPLY CONTROLLER WITH SEQUENCING  
SLVS289A MARCH 2000 REVISED OCTOBER 2000  
APPLICATION INFORMATION  
Table 3. Ripple Regulator Power Stage Components  
Ripple Regulator Section  
Ref Des  
Function  
Input bulk  
4A (EVM Design)  
C3: open  
8A  
12A  
20A  
C3, C6  
C3: 150 µF  
C3: 150 µF  
C3: 150 µF  
capacitor  
C6: 150 µF  
(Sanyo,  
C6: 150 µF  
(Sanyo,  
C6: 150 µF  
(Sanyo,  
C6: 2x150 µF  
(Sanyo,  
6TPB150M)  
6TPB150M)  
6TPB150M)  
6TPB150M)  
C11, C2  
Input high-freq  
capacitor  
C2: 0.1 µF  
C11: 0.1 µF  
(muRata  
C2: 0.1 µF  
C11: 0.1 µF  
(muRata  
C2: 0.1 µF  
C11: 0.1 µF  
(muRata  
C2: 0.33 µF  
C11: 0.33 µF  
(muRata  
GRM39X7R104K016A,  
0.1 µF, 16V, X7R)  
GRM39X7R104K016A,  
0.1 µF, 16V, X7R)  
GRM39X7R104K016A, 0.1 GRM39X7R334K016A,  
µF, 16V, X7R)  
0.33 µF, 16V, X7R)  
C13, C14 Output bulk  
capacitor  
C13: 150 µF  
(Sanyo, 6TPB150M)  
C14: open  
C13: 150 µF  
(Sanyo, 6TPB150M)  
C14: open  
C13: 150 µF  
C14: 150 µF  
(Sanyo, 6TPB150M)  
C13: 150 µF  
C14: 150 µF  
(Sanyo, 6TPB150M)  
C15,C30, Output mid-freq C15: open  
C15: open  
C30: 10 µF  
C31: 10 µF  
(muRata  
C15: 10 µF  
C30: 10 µF  
C31: 10 µF  
(muRata  
C15: 10 µF  
C30: 10 µF  
C31: 10 µF  
(muRata  
C31  
capacitor  
C30: 10 µF  
C31: 10 µF  
(muRata  
GRM39X7R106K016A,  
10 µF, 16V, X7R)  
GRM39X7R106K016A,  
10 µF, 16V, X7R)  
GRM39X7R106K016A, 10 GRM39X7R106K016A,  
µF, 16V, X7R)  
10 µF, 16V, X7R)  
C16  
Output high-freq open  
capacitor  
0.1 µF  
(muRata  
0.1 µF  
(muRata  
0.1 µF  
(muRata  
GRM39X7R104K016A,  
0.1 µF, 16V, X7R)  
GRM39X7R104K016A, 0.1 GRM39X7R104K016A,  
µF, 16V, X7R)  
0.1 µF, 16V, X7R)  
L1  
L2  
Input filter  
3.3 µH  
Coilcraft  
DO3316P332, 5.4 A  
3.3 µH  
Coilcraft  
DO3316P332,5.4 A  
1.5 µH  
Coilcraft  
DO3316P152,6.4 A  
1 µH  
Coiltronics  
UP3B1R0, 12.5A  
Output filter  
3.3 µH  
3.3 µH  
1.5 µH  
3.3 µH  
Coilcraft  
DO3316P332, 5.4 A  
Coilcraft  
Coilcraft  
Micrometals,  
T688/90 Core w/7T,  
#16, 25 A  
DO5022P332HC, 10 A DO5022P152HC,  
15 A  
R8  
Low side gate  
resistor  
10 Ω  
10 Ω  
5.1 Ω  
5.1 Ω  
Q1A,Q4  
Q1B,Q5  
Power switch  
Q1A: Dual FET  
IRF7311  
Q4: IRF7811  
Q5: IRF7811  
Q4: 2xIRF7811  
Q5: 2xIRF7811  
Q4: 2xIRF7811  
Synchronous  
switch  
Q1B: Dual FET  
IRF7311  
Q5:  
2xIRF7811  
Position available on the EVM board  
The values listed in Table 3 are recommendations based on actual test circuits. Many variations of the above  
are possible based upon the desires and/or requirements of the user. Performance of the circuit is equally, if  
not more, dependent upon the layout than on the specific components, as long as the device parameters are  
not exceeded. Fast-response, low-noise circuits require circuits require critical attention to the layout details.  
22  
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DSP POWER SUPPLY CONTROLLER WITH SEQUENCING  
SLVS289A MARCH 2000 REVISED OCTOBER 2000  
APPLICATION INFORMATION  
Table 4. LDO Power Stage Components  
LDO Section  
Ref. Des  
Q2:A  
Part  
V
IN  
V
Description  
OUT  
IRF7811(EVM)  
or  
Si4410, IRF7413  
FDS6680  
V
IN  
V
V  
Used as a power distribution switch for  
LDO output control  
IN DROPOUT  
IRF9410, Si9410  
Low cost solution for low LDO output cur-  
Q2:A  
Q2:A  
Q2: B  
rent (V V  
)*I  
< 1 W  
IN OUT OUT  
IRF7811  
Higher current and still surface mount  
1 W < (V V )*I ) < 2 W  
IN OUT OUT  
IRLZ24N  
High output current requiring heat sink.  
Low cost but throughhole package.  
(V V > 2 W  
)*I  
IN OUT OUT  
V
= I  
× RDSON. It should be as small as possible.  
DROPOUT OUT  
Position available on the EVM board  
frequency calculation  
With hysteretic control, the switching frequency is a function of the input voltage, the output voltage, the  
hysteresis window, the delay of the hysteresis comparator and the driver, the output inductance, the resistance  
in the output inductor, the output capacitance, the ESR and ESL in the output capacitor, the output current, and  
the turnon resistance of high-side and low-side MOSFET. It is a very complex equation if everything is included.  
To make it more useful to designers, a simplified equation is developed that considers only the most influential  
factors. The tolerance of the result for this equation is about 30%:  
9  
250 10  
C
T
d
V
V
V
ESR  
OUT  
IN  
OUT  
out  
f
s
9  
V
V
ESR  
250 10  
T
d
V
L
ESL  
V
IN  
IN  
hys  
OUT  
IN  
Where f is the switching frequency (Hz); V  
theoutputcapacitance;ESRistheequivalentseriesresistanceintheoutputcapacitor();ESListheequivalent  
is the output voltage (V); V is the input voltage (V); C is  
OUT  
IN  
s
OUT  
series inductance in the output capacitor (H); L  
is the output inductance (H); T is output feedback RC filter  
OUT  
d
time constant (S); V  
is the hysteresis window (V).  
hys  
output voltage setpoint calculation  
In some applications, the required output voltage is different from the VID reference voltage. In this case,  
external voltage divider can be used for the setpoint adjustment. The voltage divider is composed of two  
resistors. The equation for the setpoint is:  
R
V
top  
R
R
bottom  
V
V
O
R
Where V is the reference voltage; V is the required output voltage setpoint. V should be lower than V . In  
R
O
R
O
EVM design, the top resistor is R14 for the LDO output, or R10 for ripple regular output; the bottom resistor is  
R15 for LDO output, or R12 for ripple regulator output.  
23  
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TPS56302  
DUAL-OUTPUT LOW-INPUT-VOLTAGE  
DSP POWER SUPPLY CONTROLLER WITH SEQUENCING  
SLVS289A MARCH 2000 REVISED OCTOBER 2000  
APPLICATION INFORMATION  
hysteresis window  
The changeable hysteresis window in TPS56302 is used for switching frequency and output voltage ripple  
adjustment. The hysteresis window setup is decided by a two-resistor voltage divider on VREFB and VHYST  
pin. Two times the voltage drop on the top resistor is the hysteresis window. The formula is shown in the  
following:  
R13  
= 2 × VREFB× (1 –  
)
V
hyswindow  
R11 + R13  
Where V  
is the hysteresis window (V); VREFB is the regulated voltage from VREVB (pin 5); R11 is the  
hyswindow  
top resistor in the voltage divider; R13 is the bottom resistor in the voltage divider. The maximum hysteresis  
window is 60 mV.  
slow-start  
Slow-start reduces the start-up stresses on the power-stage components and reduces the input current surge.  
The minimum slow-start time is limited to 1 ms due to the power good function deglitch time. Slow-start timing  
is dependent on the timing capacitor value on the slow-start pin and the total resistance on VREFB. The  
following formula can be used for setting the slow-start timing:  
T
5
C
R
SLOW-START  
SLOW-START  
VREFB  
isthecapacitorvalueonSLOWST(pin3).R isthetotal  
VREFB  
T
istheslow-starttime;C  
SLOW-START  
resistance on VREFB (pin 5).  
SLOW-START  
current limit  
Current limit is implemented using the on-resistance of the upper FETs as the sensing elements. The IOUT  
signal is used for the current limit and the droop function. The voltage at IOUT at the output current trip point  
will be:  
V
R
I
2
IOUT  
ON  
O
R
is the high-side on-time resistance; I is the output current. The current limit is calculated by using the  
ON  
O
equation:  
R4  
I
2
R
0.125  
ON  
O MAX  
R5  
0.125  
Where R4 is the bottom resistor in the voltage divider on OCP pin, and R5 is the top resistor; I  
is the  
O(MAX)  
maximum current allowed; R  
is the high-side FET on-time resistance.  
ON  
Since the FET on-time resistance varies according to temperature, the current limit is basically for catastrophic  
failure.  
24  
POST OFFICE BOX 655303 DALLAS, TEXAS 75265  
TPS56302  
DUAL-OUTPUT LOW-INPUT-VOLTAGE  
DSP POWER SUPPLY CONTROLLER WITH SEQUENCING  
SLVS289A MARCH 2000 REVISED OCTOBER 2000  
APPLICATION INFORMATION  
droop compensation  
DroopcompensationwiththeoffsetresistordividerfromV  
totheVSENSEisusedtokeeptheoutputvoltage  
OUT  
in range during load transients by increasing the output voltage setpoint toward the upper tolerance limit during  
light loads and decreasing the voltage setpoint toward the lower tolerance limit during heavy loads. This allows  
the output voltage to swing a greater amount and still remain within the tolerance window. The maximum droop  
voltage is set with R6 and R7:  
R6  
R6 R7  
V
V
DROOP max  
IOUT max  
Where V  
is the maximum droop voltage; V  
is the maximum V that reflects the  
IOUT  
DROOP(max)  
IOUT(max)  
maximum output current (full load); R6 is the bottom resistor of the divider connected to the DROOP pin, R7  
is the top resistor.  
The offset voltage is set to be half of the maximum droop voltage higher than the nominal output voltage, so  
the whole droop voltage range is symmetrical to the nominal output voltage. The formula for setting the offset  
voltage is:  
1
2
R12  
R10 R12  
V
V
V
OFFSET  
DROOP max  
O
Where V  
is the desired offset voltage; V  
is the droop voltage at full load; V is the nominal  
O
OFFSET  
DROOP(max)  
output voltage; R10 is the top resistor of the offset resistor divider, and R12 is the bottom one.  
Therefore, with the setup above, at light load, the output voltage is:  
1
V
V
V
V
V
O nom  
OFFSET  
O nom  
DROOP  
V
O NO LOAD  
2
And, at full load, the output voltage is:  
1
2
V
V
V
V
O nom  
OFFSET  
O nom  
DROOP  
O FULL LOAD  
output inductor ripple current  
The output inductor current ripple can affect not only the efficiency, but also the output voltage ripple. The  
equation for calculating the inductor current ripple is exhibited in the following:  
V
V
I
r
R
IN  
OUT  
OUT  
L
DS(on)  
L
I
D
Ts  
ripple  
OUT  
Where I  
output voltage (V); I  
is the peak-to-peak ripple current (A) through the inductor; V is the input voltage (V); V  
is the  
ripple  
IN  
OUT  
is the output current; r  
is the on-time resistance of MOSFET (); R is the output  
OUT  
DS(on) L  
inductor equivalent series resistance; D is the duty cycle; and Ts is the switch cycle (S). From the equation, it  
can be seen that the current ripple can be adjusted by changing the output inductor value.  
Example:  
V
IN  
= 5 V; V  
= 1.8 V; I  
= 5 A; r  
= 10 m; R = 5 m; D = 0.36; Ts = 5 µs; L  
= 6 µH  
OUT  
OUT  
DS(on)  
L
OUT  
Then, the ripple I  
= 1 A.  
ripple  
25  
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TPS56302  
DUAL-OUTPUT LOW-INPUT-VOLTAGE  
DSP POWER SUPPLY CONTROLLER WITH SEQUENCING  
SLVS289A MARCH 2000 REVISED OCTOBER 2000  
APPLICATION INFORMATION  
output capacitor RMS current  
Assuming the inductor ripple current totally goes through the output capacitor to ground, the RMS current in the  
output capacitor can be calculated as:  
I  
I
=
O(rms)  
12  
Where I  
current (A).  
is the maximum RMS current in the output capacitor (A); I is the peak-to-peak inductor ripple  
O(rms)  
Example:  
I = 1 A, so IO(rms) = 0.29 A  
input capacitor RMS current  
The input capacitor RMS current is important for input capacitor design. Assuming the input ripple current totally  
goes into the input capacitor to the power ground, the RMS current in the input capacitor can be calculated as:  
2
2
1
12  
(
)
D
I
I
D
1
D
I
I(rms)  
O
ripple  
Where I  
is the input RMS current in the input capacitor (A); I is the output current (A); I  
is the  
I(rms)  
O
ripple  
peak-to-peak output inductor ripple current; D is the duty cycle. From the equation, it can be seen that the  
highest input RMS current usually occurs at the lowest input voltage, so it is the worst case design for input  
capacitor ripple current.  
Example:  
I
= 5 A; D = 0.36; I  
= 1 A,  
ripple  
O
Then, I  
= 2.46 A  
I(rms)  
layout and component value consideration  
Good power supply results will only occur when care is given to proper design and layout. Layout and  
component value will affect noise pickup and generation and can cause a good design to perform with less than  
expected results. With a range of current from milliamps to tens or even hundreds of amps, good power supply  
layout and component selection, especially for a fast ripple controller, is much more difficult than most general  
PCB design. The general design should proceed from the switching node to the output, then back to the driver  
section, and, finally, to placing the low-level components. In the following list are several specific points to  
consider before layout and component selection for TPS56302:  
1. All sensitive analog components should be referenced to ANAGND. These include components connected  
to SLOWST, DROOP, IOUT, OCP, VSENSE, VREFB, VHYST, BIAS, and LOSENSE/LOHIB.  
2. The input voltage range for TPS56302 is low from 2.8-V to 5.5-V, so it has a voltage tripler (charge pump)  
inside to deliver proper voltage for internal circuitry. To avoid any possible noise coupling, a low ESR  
capacitor on V  
is recommended.  
CC  
3. For the same reason in Item 2, the ANAGND and DRVGND should be connected as close as possible to  
the IC.  
4. The bypass capacitor should be placed close to the TPS56302.  
26  
POST OFFICE BOX 655303 DALLAS, TEXAS 75265  
TPS56302  
DUAL-OUTPUT LOW-INPUT-VOLTAGE  
DSP POWER SUPPLY CONTROLLER WITH SEQUENCING  
SLVS289A MARCH 2000 REVISED OCTOBER 2000  
APPLICATION INFORMATION  
layout and component value consideration (continued)  
5. When configuring the high-side driver as a boot-strap driver, the connection from BOOTLO to the power  
FETs should be as short and as wide as possible. LOSENSE/LOHIB should have a separate connection  
to the FETs since BOOTLO will have large peak current flowing through it.  
6. The bulk storage capacitors across V should be placed close to the power FETs. High-frequency bypass  
IN  
capacitors should be placed in parallel with the bulk capacitors and connected close to the drain of the  
high-side FET and to the source of the low-side FET.  
7. HISENSE and LOSENSE/LOHIB should be connected very close to the drain and source, respectively, of  
the high-side FET. HISENSE and LOSENSE/LOHIB should be routed very close to each other to minimize  
differential-mode noise coupling to these traces. Ceramic decoupling capacitors should be placed close to  
where HISENSE connects to V , to reduce high-frequency noise coupling on HISENSE.  
IN  
The EVM board (SLVP-139) is used in the test. The test results are shown in the following.  
EFFICIENCY OF  
RIPPLE REGULATOR  
RIPPLE REGULATOR (3.3 V)  
LOAD REGULATION (3.3 V)  
100  
2
V
IN  
= 5 V  
V
IN  
= 5 V  
90  
80  
70  
1
0
60  
50  
40  
1  
2  
0
1
2
3
4
5
0
1
2
3
4
5
I
O
Output Current A  
I
O
Output Current A  
Figure 23  
Figure 24  
27  
POST OFFICE BOX 655303 DALLAS, TEXAS 75265  
TPS56302  
DUAL-OUTPUT LOW-INPUT-VOLTAGE  
DSP POWER SUPPLY CONTROLLER WITH SEQUENCING  
SLVS289A MARCH 2000 REVISED OCTOBER 2000  
APPLICATION INFORMATION  
RIPPLE REGULATOR  
LINE REGULATION (3.3 V)  
LDO LOAD REGULATION (1.8 V)  
2
2
I
O
= 2 A  
V
IN  
= 5 V  
1
0
1
0
1  
2  
1  
2  
3
3.5  
4
4.5  
5
5.5  
6
0
0.2  
0.4  
I Output Current A  
O
0.6  
0.8  
1
1.2  
V
IN  
Input Voltage V  
Figure 25  
Figure 26  
SLOW-START  
DROOP COMPENSATION EFFECT  
6
10  
5
4
5
0
3.3 V  
3
2
No Droop  
280 mV  
5  
1
0
Output Voltage  
200  
1.8 V  
100  
0
220 mV  
1  
2  
With Droop  
100  
0
0.5  
1
1.5  
2
2.5  
3
3.5  
4
4.5  
5
0
4
8
12 16 20 24 28 32 36 40  
t Time ms  
t Time ms  
Figure 27  
Figure 28  
28  
POST OFFICE BOX 655303 DALLAS, TEXAS 75265  
TPS56302  
DUAL-OUTPUT LOW-INPUT-VOLTAGE  
DSP POWER SUPPLY CONTROLLER WITH SEQUENCING  
SLVS289A MARCH 2000 REVISED OCTOBER 2000  
APPLICATION INFORMATION  
layouts  
2.7 in  
Figure 29. Top Layer  
Figure 30. Bottom Layer (Top View)  
29  
POST OFFICE BOX 655303 DALLAS, TEXAS 75265  
TPS56302  
DUAL-OUTPUT LOW-INPUT-VOLTAGE  
DSP POWER SUPPLY CONTROLLER WITH SEQUENCING  
SLVS289A MARCH 2000 REVISED OCTOBER 2000  
APPLICATION INFORMATION  
bill of materials  
REF  
PN  
Description  
MFG  
Size  
C1  
10TPA33M  
Std  
Capacitor, POSCAP, 33 µF, 10 V  
Capacitor, Ceramic, 10 µF, 16 V  
Capacitor, POSCAP, 150 µF, 6 V  
Capacitor, Ceramic, 0.1 µF, 16 V  
Capacitor, Ceramic, 1 µF, 16 V  
Open  
Sanyo  
Sanyo  
Sanyo  
Sanyo  
Sanyo  
C
C2, C20, C21, C30, C31  
1210  
D
C3. C6, C8, C13, C25  
6TPB150M  
Std  
C4, C5, C11, C12, C23, C26, C27,  
603  
C7, C22  
C9  
Std  
805  
Std  
1210  
603  
C10, C16  
C14, C15  
C17, C24  
C18, C19  
D1  
Std  
Open  
Std  
Open  
D
Std  
Capacitor, Ceramic, 1000 pF, 16 V  
Capacitor, Ceramic, 1 µF, 16 V  
Diode, LED, Green, 2.1 V SM  
Inductor, 3.3 µH, 5.4 A  
Sanyo  
Sanyo  
Lumwx  
Coilcraft  
OST  
603  
Std  
805  
SML-LX2832G  
DO3316P-332  
ED2227  
ED1515  
S1132-3-ND  
1210  
0.5 × 0.37 in  
5.08 mm  
n, 6 A,  
#S1132-3-ND  
L1, L2  
J1  
Terminal Block, 4-pin, 15 A, 5.08 mm  
Terminal Block, 3-pin, 6 A, 3.5 mm  
J2  
OST  
JP1, JP2  
Header, Right straight, 3-pin, 0.1 ctrs,  
Sullins  
0.3pins  
JP1shunt  
J3  
929950-00-ND  
S1132-2-ND  
Shunt jumper, 0.1(for JP1)  
3M  
0.1”  
Header, Right straight, 2-pin, 0.1 ctrs,  
0.3pins  
Sullins  
#S1132-2-ND  
Q1  
Open  
SO-8  
SO-8  
TO220  
TO-236  
603  
Q2:A, Q4, Q5  
Q2:B  
Q3  
IRF7811  
MOSFET, N-ch, 30 V, 10 mΩ  
Open  
2N7002DICT-N  
MOSFET, N-ch, 115 mA, 1.2 Ω  
Resistor, 10 kohms, 5 %  
Resistor, 1 kohms, 1%  
Resistor, 0 ohms, 1%  
Resistor, 1 kohms, 1%  
Resistor, 3.32 kohms, 1%  
Resistor, 10 ohms, 5 %  
Resistor, 2.7 ohms, 5 %  
Resistor, 150 ohms, 5 %  
Resistor, 100 ohms, 1 %  
Resistor, 10 kohms, 5 %  
Resistor, 20.0 kohms, 1 %  
Resistor, 0 ohms, 5%  
Resistor, open  
Diodes, Inc.  
R3  
std  
R4  
std  
603  
R5  
std  
603  
R6  
std  
603  
R7  
std  
603  
R8  
std  
603  
R9  
std  
1206  
603  
R10  
R11  
std  
std  
603  
R12  
R13  
R14  
R15  
R16  
TP1TP10  
TP11  
std  
603  
std  
603  
std  
603  
std  
603  
std  
Resistor, 15 kohms, 5 %  
Test Point, Red  
805  
240345  
131424400  
Farnell  
Adaptor, 3.5-mm probe clip  
Tektronix  
(or 131503100)  
U1  
TPS56302PWP  
Dual controller  
TSSOP28pin  
30  
POST OFFICE BOX 655303 DALLAS, TEXAS 75265  
TPS56302  
DUAL-OUTPUT LOW-INPUT-VOLTAGE  
DSP POWER SUPPLY CONTROLLER WITH SEQUENCING  
SLVS289A MARCH 2000 REVISED OCTOBER 2000  
APPLICATION INFORMATION  
Power Supply  
+
Load  
0 4 A  
5V, 5A Supply  
+
6.8 Ohms  
2 W  
Jumper Pins 23  
NOTE A: All wire pairs should be twisted.  
Figure 31. Test Setup  
31  
POST OFFICE BOX 655303 DALLAS, TEXAS 75265  
TPS56302  
DUAL-OUTPUT LOW-INPUT-VOLTAGE  
DSP POWER SUPPLY CONTROLLER WITH SEQUENCING  
SLVS289A MARCH 2000 REVISED OCTOBER 2000  
APPLICATION INFORMATION  
DSP power application  
In DSP power applications, TPS56302 is used in the applications that require more current for peripheral and  
DSP I/O. The power good (PG) output can be used for monitoring or controlling as an optional function. In the  
EVM schematic, Q3, D1, R1, and R2 are the circuit to show this function.  
RR  
LDO  
Output  
Output  
Ripple  
Regulator  
V
IN  
LDO  
Core  
DSP  
I/O  
Peripheral  
PG output (optional)  
Figure 32. TPS56302 For High Peripheral Current DSP Application  
TPS56300is used in the applications that require high current for core, but low current for I/O. Another important  
feature is that, if the input voltage is the same as the LDO output, the LDO switch acts as a distribution switch  
to control the on/off of the LDO output.  
RR Output  
Ripple  
Regulator  
V
IN  
Core  
DSP  
LDO Output  
I/O  
LDO  
PG output (optional)  
Figure 33. TPS56300 For On/Off Control DSP Application  
32  
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TPS56302  
DUAL-OUTPUT LOW-INPUT-VOLTAGE  
DSP POWER SUPPLY CONTROLLER WITH SEQUENCING  
SLVS289A MARCH 2000 REVISED OCTOBER 2000  
MECHANICAL DATA  
PWP (R-PDSO-G**)  
PowerPAD PLASTIC SMALL-OUTLINE PACKAGE  
20-PIN SHOWN  
0,30  
0,19  
11  
0,65  
20  
M
0,10  
Thermal Pad  
(See Note D)  
0,15 NOM  
4,50  
4,30  
6,60  
6,20  
Gage Plane  
1
10  
0,25  
A
0°8°  
0,75  
0,50  
Seating Plane  
0,10  
0,15  
0,05  
1,20 MAX  
PINS **  
14  
16  
20  
24  
28  
DIM  
5,10  
4,90  
5,10  
4,90  
6,60  
6,40  
7,90  
7,70  
9,80  
9,60  
A MAX  
A MIN  
4073225/E 03/97  
NOTES: A. All linear dimensions are in millimeters.  
B. This drawing is subject to change without notice.  
C. Body dimensions do not include mold flash or protrusions.  
D. Thepackagethermalperformancemaybeenhancedbybondingthethermalpadtoanexternalthermalplane.Thispadiselectrically  
and thermally connected to the backside of the die and possibly selected leads.  
E. Falls within JEDEC MO-153  
PowerPAD is a trademark of Texas Instruments.  
33  
POST OFFICE BOX 655303 DALLAS, TEXAS 75265  
IMPORTANT NOTICE  
Texas Instruments and its subsidiaries (TI) reserve the right to make changes to their products or to discontinue  
any product or service without notice, and advise customers to obtain the latest version of relevant information  
to verify, before placing orders, that information being relied on is current and complete. All products are sold  
subject to the terms and conditions of sale supplied at the time of order acknowledgment, including those  
pertaining to warranty, patent infringement, and limitation of liability.  
TI warrants performance of its products to the specifications applicable at the time of sale in accordance with  
TIsstandardwarranty. TestingandotherqualitycontroltechniquesareutilizedtotheextentTIdeemsnecessary  
to support this warranty. Specific testing of all parameters of each device is not necessarily performed, except  
those mandated by government requirements.  
Customers are responsible for their applications using TI components.  
In order to minimize risks associated with the customers applications, adequate design and operating  
safeguards must be provided by the customer to minimize inherent or procedural hazards.  
TI assumes no liability for applications assistance or customer product design. TI does not warrant or represent  
that any license, either express or implied, is granted under any patent right, copyright, mask work right, or other  
intellectual property right of TI covering or relating to any combination, machine, or process in which such  
products or services might be or are used. TIs publication of information regarding any third partys products  
or services does not constitute TIs approval, license, warranty or endorsement thereof.  
Reproduction of information in TI data books or data sheets is permissible only if reproduction is without  
alteration and is accompanied by all associated warranties, conditions, limitations and notices. Representation  
or reproduction of this information with alteration voids all warranties provided for an associated TI product or  
service, is an unfair and deceptive business practice, and TI is not responsible nor liable for any such use.  
Resale of TIs products or services with statements different from or beyond the parameters stated by TI for  
that product or service voids all express and any implied warranties for the associated TI product or service,  
is an unfair and deceptive business practice, and TI is not responsible nor liable for any such use.  
Also see: Standard Terms and Conditions of Sale for Semiconductor Products. www.ti.com/sc/docs/stdterms.htm  
Mailing Address:  
Texas Instruments  
Post Office Box 655303  
Dallas, Texas 75265  
Copyright 2001, Texas Instruments Incorporated  

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