ICS874S02BMILF [IDT]

PLL Based Clock Driver, 874S Series, 1 True Output(s), 0 Inverted Output(s), PDSO20, 7.50 X 12.80 MM, 2.30 MM HEIGHT, ROHS COMPLIANT, MS-013, MO-119, SOIC-20;
ICS874S02BMILF
型号: ICS874S02BMILF
厂家: INTEGRATED DEVICE TECHNOLOGY    INTEGRATED DEVICE TECHNOLOGY
描述:

PLL Based Clock Driver, 874S Series, 1 True Output(s), 0 Inverted Output(s), PDSO20, 7.50 X 12.80 MM, 2.30 MM HEIGHT, ROHS COMPLIANT, MS-013, MO-119, SOIC-20

驱动 光电二极管 逻辑集成电路
文件: 总16页 (文件大小:685K)
中文:  中文翻译
下载:  下载PDF数据表文档文件
1:1 DIFFERENTIAL-TO-LVDS ZERO DELAY CLOCK GENERATOR  
ICS874S02I  
General Description  
Features  
The ICS874S02I is a highly versatile 1:1 Differential-  
One differential LVDS output pair and  
one differential feedback output pair  
S
IC  
to-LVDS Clock Generator and a member of the  
HiPerClockS™ family of High Performance Clock  
Solutions from IDT. The ICS874S02I has a fully  
integrated PLL and can be configured as a zero  
HiPerClockS™  
One differential clock input pair  
CLK/nCLK can accept the following differential input levels:  
LVPECL, LVDS, LVHSTL, SSTL  
delay buffer, multiplier or divider, and has an output frequency  
range of 62.5MHz to 1GHz. The reference divider, feedback  
divider and output divider are each programmable, thereby  
allowing for the following output-to-input frequency ratios: 8:1, 4:1,  
2:1, 1:1, 1:2, 1:4, 1:8. The external feedback allows the device to  
achieve “zero delay” between the input clock and the output  
clocks. The PLL_SEL pin can be used to bypass the PLL for  
system test and debug purposes. In bypass mode, the reference  
clock is routed around the PLL and into the internal output  
dividers.  
Input frequency range: 62.5MHz to 1GHz  
Output frequency range: 62.5MHz to 1GHz  
VCO range: 500MHz - 1GHz  
External feedback for "zero delay" clock regeneration with  
configurable frequencies  
Programmable dividers allow for the following output-to-input  
frequency ratios: 8:1, 4:1, 2:1, 1:1, 1:2, 1:4, 1:8  
Cycle-to-cycle jitter: 35ps (maximum)  
Static phase offset: 100ps  
Full 3.3V supply mode  
-40°C to 85°C ambient operating temperature  
Available in standard (RoHS 5) package  
Block Diagram  
Pin Assignment  
Pullup  
CLK  
nCLK  
MR  
1
2
20 SEL1  
19  
SEL0  
PLL_SEL  
Q
nQ  
÷1, ÷2, ÷4, ÷8,  
3
4
18 VDD  
17 PLL_SEL  
0
÷16, ÷32, ÷64  
nFB_IN  
B
nQFB  
QF  
FB_IN  
SEL2  
VDDO  
5
6
7
16  
15  
14  
13  
VDDA  
SEL3  
GND  
Pulldown  
CLK  
nCLK  
1
Pullup  
nQFB  
QFB  
GND  
8
Q
PLL  
9
10  
12 nQ  
VDDO  
11  
8:1, 4:1, 2:1, 1:1,  
1:2, 1:4, 1:8  
Pulldown  
Pullup  
ICS874S02I  
FB_IN  
nFB_IN  
20-Lead SOIC  
7.5mm x 12.8mm x 2.3mm package body  
M Package  
Top View  
Pulldown  
Pulldown  
Pulldown  
Pulldown  
Pulldown  
SEL0  
SEL1  
SEL2  
SEL3  
MR  
IDT™ / ICS™ LVDS CLOCK GENERATOR  
1
ICS874S02BMI REV. AOCTOBER 16, 2008  
ICS874S02I  
1:1 DIFFERENTIAL-TO-LVDS ZERO DELAY CLOCK GENERATOR  
Table 1. Pin Descriptions  
Number  
Name  
CLK  
Type  
Description  
1
2
Input  
Input  
Pulldown Non-inverting differential clock input.  
nCLK  
Pullup  
Inverting differential clock input.  
Active HIGH Master Reset. When logic HIGH, the internal dividers are reset  
causing the true outputs Q and QFB to go low and the inverted outputs nQ and  
nQFB to go high. When logic LOW, the internal dividers and the outputs are  
enabled. LVCMOS / LVTTL interface levels.  
3
MR  
Input  
Pulldown  
Inverting differential feedback input to phase detector for regenerating clocks  
with “Zero Delay.” Connect to pin 8.  
4
5
nFB_IN  
FB_IN  
Input  
Input  
Input  
Pullup  
Non-inverted differential feedback input to phase detector for regenerating  
clocks with “Zero Delay.” Connect to pin 9.  
Pulldown  
6, 15,  
19, 20  
SEL2, SEL3,  
SEL0, SEL1  
Pulldown Determines output divider values in Table 3. LVCMOS / LVTTL interface levels.  
7, 11  
8, 9  
VDDO  
nQFB, QFB  
GND  
Power  
Output  
Power  
Output  
Power  
Output supply pins.  
Differential feedback output pair. HSTL interface levels.  
Power supply ground.  
10, 14  
12, 13  
16  
nQ, Q  
Differential clock output pair. HSTL interface levels.  
Analog supply pin.  
VDDA  
PLL select. Selects between the PLL and reference clock as the input to the  
17  
18  
PLL_SEL  
Input  
Pullup  
dividers. When LOW, selects reference clock. When HIGH, selects PLL.  
LVCMOS/LVTTL interface levels.  
VDD  
Power  
Core supply pin.  
NOTE: Pullup and Pulldown refer to internal input resistors. See Table 2, Pin Characteristics, for typical values.  
Table 2. Pin Characteristics  
Symbol  
CIN  
Parameter  
Test Conditions  
Minimum  
Typical  
Maximum  
Units  
pF  
Input Capacitance  
Input Pullup Resistor  
2
RPULLUP  
50  
50  
k  
RPULLDOWN Input Pulldown Resistor  
kΩ  
IDT™ / ICS™ LVDS CLOCK GENERATOR  
2
ICS874S02BMI REV. AOCTOBER 16, 2008  
ICS874S02I  
1:1 DIFFERENTIAL-TO-LVDS ZERO DELAY CLOCK GENERATOR  
Function Tables  
Table 3A. Control Input Function Table  
Inputs  
Outputs  
PLL_SEL = 1  
PLL Enable Mode  
SEL3  
SEL2  
SEL1  
SEL0  
Reference Frequency Range (MHz)*  
500 - 1000  
250 - 500  
Q/nQ  
÷1  
÷1  
÷1  
÷1  
÷2  
÷2  
÷2  
÷4  
÷4  
÷8  
x2  
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
125 - 250  
62.5 - 125  
500 - 1000  
250 - 500  
125 - 250  
500 - 1000  
250 - 500  
500 - 1000  
250 - 500  
125 - 250  
x2  
62.5 - 125  
x2  
125 - 250  
x4  
62.5 - 125  
x4  
62.5 - 125  
x8  
*NOTE: VCO frequency range for all configurations above is 500MHz to 1GHz.  
IDT™ / ICS™ LVDS CLOCK GENERATOR  
3
ICS874S02BMI REV. AOCTOBER 16, 2008  
ICS874S02I  
1:1 DIFFERENTIAL-TO-LVDS ZERO DELAY CLOCK GENERATOR  
Table 3B. PLL Bypass Function Table  
Inputs  
Outputs  
PLL_SEL = 0  
PLL Bypass Mode  
SEL3  
SEL2  
SEL1  
SEL0  
Q/nQ  
÷4  
0z  
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
÷4  
÷4  
÷8  
÷8  
÷8  
÷16  
÷16  
÷32  
÷64  
÷2  
÷2  
÷4  
÷1  
÷2  
÷1  
IDT™ / ICS™ LVDS CLOCK GENERATOR  
4
ICS874S02BMI REV. AOCTOBER 16, 2008  
ICS874S02I  
1:1 DIFFERENTIAL-TO-LVDS ZERO DELAY CLOCK GENERATOR  
Absolute Maximum Ratings  
NOTE: Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device.  
These ratings are stress specifications only. Functional operation of product at these conditions or any conditions beyond  
those listed in the DC Characteristics or AC Characteristics is not implied. Exposure to absolute maximum rating conditions for  
extended periods may affect product reliability.  
Item  
Rating  
Supply Voltage, VDD  
Inputs, VI  
4.6V  
-0.5V to VDD + 0.5V  
Outputs, IO (LVDS)  
Continuos Current  
Surge Current  
10mA  
15mA  
Package Thermal Impedance, θJA  
64.7°C/W (0 lfpm)  
Storage Temperature, TSTG  
-65°C to 150°C  
DC Electrical Characteristics  
Table 4A. LVDS Power Supply DC Characteristics, VDD = VDDO = 3.3V 5ꢀ, TA = -40°C to 85°C  
Symbol  
VDD  
Parameter  
Test Conditions  
Minimum  
3.135  
Typical  
3.3  
Maximum  
3.465  
VDD  
Units  
V
Core Supply Voltage  
Analog Supply Voltage  
Output Supply Voltage  
Power Supply Current  
Analog Supply Current  
Output Supply Current  
VDDA  
VDDO  
IDD  
VDD – 0.20  
3.135  
3.3  
V
3.3  
3.465  
97  
V
mA  
mA  
mA  
IDDA  
20  
IDDO  
40  
Table 4B. LVCMOS/LVTTL DC Characteristics, VDD = VDDO = 3.3V 5ꢀ, TA = -40°C to 85°C  
Symbol Parameter  
Test Conditions  
Minimum  
2.2  
Typical  
Maximum  
VDD + 0.3  
0.8  
Units  
V
VIH  
VIL  
Input High Voltage  
Input Low Voltage  
-0.3  
V
MR, SEL[0:3]  
PLL_SEL  
V
DD = VIN = 3.465V  
150  
µA  
µA  
µA  
µA  
IIH  
Input High Current  
VDD = VIN = 3.465V  
10  
MR, SEL[0:3]  
PLL_SEL  
V
DD = 3.465V, VIN = 0V  
-10  
IIL  
Input Low Current  
VDD = 3.465V, VIN = 0V  
-150  
IDT™ / ICS™ LVDS CLOCK GENERATOR  
5
ICS874S02BMI REV. AOCTOBER 16, 2008  
ICS874S02I  
1:1 DIFFERENTIAL-TO-LVDS ZERO DELAY CLOCK GENERATOR  
Table 4C. Differential DC Characteristics, VDD = VDDO = 3.3V 5ꢀ, TA = -40°C to 85°C  
Symbol Parameter  
Test Conditions  
Minimum  
Typical  
Maximum  
150  
Units  
µA  
µA  
µA  
µA  
V
CLK, FB_IN  
V
DD = VIN = 3.465V  
VDD = VIN = 3.465V  
DD = 3.465V, VIN = 0V  
IIH Input High Current  
nCLK, nFB_IN  
CLK, FB_IN  
10  
V
-10  
-150  
IIL  
Input Low Current  
nCLK, nFB_IN  
VDD = 3.465V, VIN = 0V  
VPP  
Peak-to-Peak Input Voltage; NOTE 1  
0.15  
1.3  
VCMR  
Common Mode Input Voltage; NOTE 1, 2  
GND + 0.5  
VDD – 0.85  
V
NOTE 1: VIL should not be less than -0.3V.  
NOTE 2: Common mode input voltage is defined as VIH.  
Table 4D. LVDS DC Characteristics, VDD = VDDO = 3.3V 5ꢀ, TA = -40°C to 85°C  
Symbol  
VOD  
Parameter  
Test Conditions  
Minimum  
Typical  
Maximum  
550  
Units  
mV  
mV  
V
Differential Output Voltage  
VOD Magnitude Change  
Offset Voltage  
350  
450  
VOD  
VOS  
50  
1.20  
1.33  
1.45  
50  
VOS  
VOS Magnitude Change  
mV  
Table 5. Input Frequency Characteristics, VDD = VDDO = 3.3V 5ꢀ, TA = -40°C to 85°C  
Symbol  
Parameter  
Test Conditions  
PLL_SEL = 1  
PLL_SEL = 0  
Minimum  
Typical  
Maximum  
1000  
Units  
MHz  
MHz  
62.5  
FIN  
Input Frequency  
CLK/nCLK  
1000  
Table 6. AC Characteristics, VDD = VDDO = 3.3V 5ꢀ, TA = -40°C to 85°C  
Parameter  
fOUT  
Symbol  
Test Conditions  
Minimum  
62.5  
Typical  
Maximum  
Units  
MHz  
ps  
Output Frequency  
1000  
100  
35  
tsk(Ø)  
tjit(cc)  
tL  
Static Phase Offset; NOTE 1, 2  
Cycle-to-Cycle Jitter; NOTE 2  
PLL Lock Time  
PLL_SEL = 1  
-100  
ps  
1
ms  
ps  
tR / tF  
odc  
Output Rise/Fall Time  
Output Duty Cycle  
20ꢀ to 80ꢀ  
50  
47  
250  
53  
NOTE: Electrical parameters are guaranteed over the specified ambient operating temperature range, which is established when device  
is mounted in a test socket with maintained transverse airflow greater than 500 lfpm. Device will meet specifications after thermal  
equilibrium has been reached under these conditions.  
NOTE 1: Defined as the time difference between the input reference clock and the average feedback input signal, when the PLL is locked  
and the input reference frequency is stable.  
NOTE 2: This parameter is defined in accordance with JEDEC Standard 65.  
IDT™ / ICS™ LVDS CLOCK GENERATOR  
6
ICS874S02BMI REV. AOCTOBER 16, 2008  
ICS874S02I  
1:1 DIFFERENTIAL-TO-LVDS ZERO DELAY CLOCK GENERATOR  
Parameter Measurement Information  
V
DD  
nCLK  
CLK  
SCOPE  
Qx  
V
VPP  
VCMR  
Cross Points  
DD,  
3.3V 5ꢀ  
V
POWER SUPPLY  
DDO  
V
+
Float GND –  
LVDS  
DDA  
nQx  
GND  
3.3V LVDS Output Load AC Test Circuit  
Differential Input Level  
nCLK  
CLK  
VOH  
VOL  
nQ, nQFB  
nFB_IN  
VOH  
VOL  
Q, QFB  
FB_IN  
tcycle n  
tcycle n+1  
t(Ø)  
tjit(cc) = tcycle n – tcycle n+1  
|
|
tjit(Ø) = t(Ø) – t(Ø) mean= Phase Jitter  
t(Ø) mean = Static Phase Offset  
1000 Cycles  
Where t(Ø) is any random sample, and t(Ø) mean is the average  
of the sampled cycles measured on the controlled edges)  
Static Phase Offset  
Cycle-to-Cycle Jitter  
nQ, nQFB  
Q, QFB  
nQ, nQFB  
Q, QFB  
80ꢀ  
tF  
80ꢀ  
tR  
tPW  
VOD  
20ꢀ  
tPERIOD  
20ꢀ  
tPW  
odc =  
x 100ꢀ  
tPERIOD  
Output Duty Cycle/Pulse Width/Period  
Output Rise/Fall Time  
IDT™ / ICS™ LVDS CLOCK GENERATOR  
7
ICS874S02BMI REV. AOCTOBER 16, 2008  
ICS874S02I  
1:1 DIFFERENTIAL-TO-LVDS ZERO DELAY CLOCK GENERATOR  
Parameter Measurement Information, continued  
VDD  
VDD  
out  
out  
out  
out  
DC Input  
LVDS  
LVDS  
DC Input  
100  
V
OD/VOD  
VOS/VOS  
Differential Output Voltage Setup  
Offset Voltage Setup  
Application Information  
Recommendations for Unused Input and Output Pins  
Inputs:  
Outputs:  
LVCMOS Control Pins  
LVDS Outputs  
All control pins have internal pull-ups or pull-downs; additional  
resistance is not required but can be added for additional  
protection. A 1kresistor can be used.  
All unused LVDS output pairs can be either left floating or  
terminated with 100across. If they are left floating, there should  
be no trace attached.  
IDT™ / ICS™ LVDS CLOCK GENERATOR  
8
ICS874S02BMI REV. AOCTOBER 16, 2008  
ICS874S02I  
1:1 DIFFERENTIAL-TO-LVDS ZERO DELAY CLOCK GENERATOR  
Power Supply Filtering Technique  
As in any high speed analog circuitry, the power supply pins are  
vulnerable to random noise. To achieve optimum jitter perform-  
ance, power supply isolation is required. The ICS874S02I provides  
separate power supplies to isolate any high switching noise from  
the outputs to the internal PLL. VDD, VDDA and VDDO should be  
individually connected to the power supply plane through vias, and  
0.01µF bypass capacitors should be used for each pin. Figure 1  
illustrates this for a generic VDD pin and also shows that VDDA  
requires that an additional 10resistor along with a 10µF bypass  
capacitor be connected to the VDDA pin.  
3.3V  
VDD  
.01µF  
.01µF  
10Ω  
VDDA  
10µF  
Figure 1. Power Supply Filtering  
Wiring the Differential Input to Accept Single-Ended Levels  
Figure 2 shows how the differential input can be wired to accept  
single-ended levels. The reference voltage V_REF = VDD/2 is  
generated by the bias resistors R1, R2 and C1. This bias circuit  
should be located as close as possible to the input pin. The ratio of  
R1 and R2 might need to be adjusted to position the V_REF in the  
center of the input voltage swing. For example, if the input clock  
swing is only 2.5V and VDD = 3.3V, V_REF should be 1.25V and  
VDD  
R1  
1K  
Single Ended Clock Input  
R2/R1 = 0.609.  
CLK  
V_REF  
nCLK  
C1  
0.1u  
R2  
1K  
Figure 2. Single-Ended Signal Driving Differential Input  
IDT™ / ICS™ LVDS CLOCK GENERATOR  
9
ICS874S02BMI REV. AOCTOBER 16, 2008  
ICS874S02I  
1:1 DIFFERENTIAL-TO-LVDS ZERO DELAY CLOCK GENERATOR  
Differential Clock Input Interface  
The CLK /nCLK accepts LVDS, LVPECL, LVHSTL, SSTL, and  
other differential signals. Both signals must meet the VPP and  
VCMR input requirements. Figures 3A to 3E show interface  
examples for the HiPerClockS CLK/nCLK input driven by the most  
common driver types. The input interfaces suggested here are  
examples only. Please consult with the vendor of the driver  
component to confirm the driver termination requirements. For  
example, in Figure 3A, the input termination applies for IDT  
HiPerClockS open emitter LVHSTL drivers. If you are using an  
LVHSTL driver from another vendor, use their termination  
recommendation.  
3.3V  
3.3V  
3.3V  
1.8V  
Zo = 50  
Zo = 50Ω  
CLK  
CLK  
Zo = 50Ω  
nCLK  
Zo = 50Ω  
HiPerClockS  
Input  
nCLK  
LVPECL  
HiPerClockS  
LVHSTL  
R1  
50  
R2  
50  
Input  
R1  
50  
R2  
50  
IDT  
HiPerClockS  
LVHSTL Driver  
R2  
50  
3A. HiPerClockS CLK/nCLK Input Driven by an IDT  
Open Emitter HiPerClockS LVHSTL Driver  
Figure 3B. HiPerClockS CLK/nCLK Input  
Driven by a 3.3V LVPECL Driver  
3.3V  
3.3V  
3.3V  
3.3V  
3.3V  
R3  
125  
R4  
125  
Zo = 50Ω  
Zo = 50Ω  
Zo = 50Ω  
CLK  
CLK  
R1  
100  
nCLK  
nCLK  
Zo = 50Ω  
Receiver  
HiPerClockS  
Input  
LVPECL  
LVDS  
R1  
84  
R2  
84  
Figure 3D. HiPerClockS CLK/nCLK Input  
Driven by a 3.3V LVDS Driver  
Figure 3C. HiPerClockS CLK/nCLK Input  
Driven by a 3.3V LVPECL Driver  
2.5V  
3.3V  
2.5V  
R3  
R4  
120  
120  
Zo = 60Ω  
Zo = 60Ω  
CLK  
nCLK  
HiPerClockS  
SSTL  
R1  
120  
R2  
120  
Figure 3E. HiPerClockS CLK/nCLK Input  
Driven by a 2.5V SSTL Driver  
IDT™ / ICS™ LVDS CLOCK GENERATOR  
10  
ICS874S02BMI REV. AOCTOBER 16, 2008  
ICS874S02I  
1:1 DIFFERENTIAL-TO-LVDS ZERO DELAY CLOCK GENERATOR  
3.3V LVDS Driver Termination  
A general LVDS interface is shown in Figure 4. In a 100Ω  
differential transmission line environment, LVDS drivers require a  
matched load termination of 100across near the receiver input.  
For a multiple LVDS outputs buffer, if only partial outputs are used,  
it is recommended to terminate the unused outputs.  
3.3V  
50Ω  
3.3V  
LVDS Driver  
+
R1  
100Ω  
50Ω  
100Differential Transmission Line  
Figure 4. Typical LVDS Driver Termination  
Schematic Example  
The schematic of the ICS874S02I layout example is shown in  
Figure 5A. The ICS874S02I recommended PCB board layout for  
this example is shown in Figure 5B. This layout example is used as  
a general guideline. The layout in the actual system will depend on  
the selected component types and the density of the P.C. board.  
3.3V  
(155.52 MHz)  
U1  
Zo = 50 Ohm  
SEL1  
SEL0  
1
2
3
20  
19  
18  
17  
16  
15  
14  
13  
12  
11  
C1  
0.1uF  
CLK  
SEL1  
SEL0  
VDDI  
PLL_SEL  
VDDA  
SEL3  
GND  
nCLK  
MR  
VDD  
PLL_SEL  
VDDA  
Zo = 50 Ohm  
3.3V PECL Driv er  
4
5
R7  
VDD  
nFB_IN  
FB_IN  
SEL2  
VDDO  
nQFB  
QFB  
SEL2  
VDDO  
6
SEL3  
7
10  
C16  
8
C11  
Q
9
0.01u  
nQ  
R8  
50  
R9  
50  
10  
VDDO  
10u  
GND  
VDDO  
R2  
100  
ICS8745B-21  
ICS874S02I  
SP = Space (i.e. not intstalled)  
(77.76 MHz)  
R10  
50  
VDD  
+
-
RU3  
1K  
RU4  
1K  
RU5  
SP  
RU6  
1K  
RU7  
SP  
Bypass capacitors located  
near the power pins  
R4  
PLL_SEL  
SEL0  
100  
LVDS_input  
VDD=3.3V  
VDDO=3.3V  
SEL1  
(U1-7)  
(U1-11)  
SEL2  
VDDO  
SEL3  
C4  
0.1uF  
C2  
0.1uF  
Zo = 100 Ohm Dif ferential  
RD3  
SP  
RD4  
SP  
RD5  
1K  
RD6  
SP  
RD7  
1K  
SEL[3:0] = 0101,  
Divide by 2  
Figure 5A. ICS874S02I LVDS Zero Delay Buffer Schematic Example  
IDT™ / ICS™ LVDS CLOCK GENERATOR  
11  
ICS874S02BMI REV. AOCTOBER 16, 2008  
ICS874S02I  
1:1 DIFFERENTIAL-TO-LVDS ZERO DELAY CLOCK GENERATOR  
The following component footprints are used in this layout  
example.  
trace delay might be restricted by the available space on the board  
and the component location. While routing the traces, the clock  
signal traces should be routed first and should be locked prior to  
routing other signal traces.  
All the resistors and capacitors are size 0603.  
• The 100differential output traces should have the same  
length.  
Power and Grounding  
Place the decoupling capacitors as close as possible to the power  
pins. If space allows, placement of the decoupling capacitor on the  
component side is preferred. This can reduce unwanted  
inductance between the decoupling capacitor and the power pin  
caused by the via.  
• Avoid sharp angles on the clock trace. Sharp angle turns  
cause the characteristic impedance to change on the  
transmission lines.  
• Keep the clock traces on the same layer. Whenever possible,  
avoid placing vias on the clock traces. Placement of vias on  
the traces can affect the trace characteristic impedance and  
hence degrade signal integrity.  
Maximize the power and ground pad sizes and number of vias  
capacitors. This can reduce the inductance between the power and  
ground planes and the component power and ground pins.  
To prevent cross talk, avoid routing other signal traces in  
parallel with the clock traces. If running parallel traces is  
unavoidable, allow a separation of at least three trace widths  
between the differential clock trace and the other signal trace.  
The RC filter consisting of R7, C11, and C16 should be placed as  
close to the VDDA pin as possible.  
Clock Traces and Termination  
• Make sure no other signal traces are routed between the  
clock trace pair.  
Poor signal integrity can degrade the system performance or cause  
system failure. In synchronous high-speed digital systems, the  
clock signal is less tolerant to poor signal integrity than other  
signals. Any ringing on the rising or falling edge or excessive ring  
back can cause system failure. The shape of the trace and the  
• The series termination resistors should be located as close to  
the driver pins as possible.  
U1  
ICS874S02I  
ICS8745B-21  
GND  
VDDO  
C1  
VDD  
C16  
VDDA  
VIA  
C11  
C4  
R7  
100 Ohm  
Differential  
Traces  
C2  
Figure 5B. PCB Board Layout for ICS874S02I  
IDT™ / ICS™ LVDS CLOCK GENERATOR  
12  
ICS874S02BMI REV. AOCTOBER 16, 2008  
ICS874S02I  
1:1 DIFFERENTIAL-TO-LVDS ZERO DELAY CLOCK GENERATOR  
Power Considerations  
This section provides information on power dissipation and junction temperature for the ICS874S02I.  
Equations and example calculations are also provided.  
1. Power Dissipation.  
The total power dissipation for the ICS874S02I is the sum of the core power plus the analog power plus the power dissipated in the load(s).  
The following is the power dissipation for VDD = 3.3V + 5ꢀ = 3.465V, which gives worst case results.  
The maximum current at 85°C is as follows:  
IDD_MAX = 93mA  
IDDA_MAX = 19mA  
IDDO_MAX = 36mA  
Power (core)MAX = VDD_MAX * (IDD_MAX + IDDA_MAX) = 3.465V * (93mA + 19mA) = 388.08mW  
Power (outputs)MAX = VDDO_MAX* IDDO_MAX = 3.465V * 36mA = 124.74mW  
Total Power_MAX = 388.08mW + 124.74mW = 512.82mW  
2. Junction Temperature.  
Junction temperature, Tj, is the temperature at the junction of the bond wire and bond pad and directly affects the reliability of the device.  
The maximum recommended junction temperature for HiPerClockS devices is 125°C.  
The equation for Tj is as follows: Tj = θJA * Pd_total + TA  
Tj = Junction Temperature  
θJA = Junction-to-Ambient Thermal Resistance  
Pd_total = Total Device Power Dissipation (example calculation is in section 1 above)  
TA = Ambient Temperature  
In order to calculate junction temperature, the appropriate junction-to-ambient thermal resistance θJA must be used. Assuming no air flow  
and a multi-layer board, the appropriate value is 64.7°C/W per Table 7 below.  
Therefore, Tj for an ambient temperature of 85°C with all outputs switching is:  
85°C + 0.513W * 64.7°C/W = 118.2°C. This is well below the limit of 125°C.  
This calculation is only an example. Tj will obviously vary depending on the number of loaded outputs, supply voltage, air flow and the type  
of board (single layer or multi-layer).  
Table 7. Thermal Resistance θJA for 20 Lead SOIC, Forced Convection  
θJA by Velocity  
Linear Feet per Minute  
0
200  
500  
Multi-Layer PCB, JEDEC Standard Test Boards  
64.7°C/W  
56.7°C/W  
53.5°C/W  
IDT™ / ICS™ LVDS CLOCK GENERATOR  
13  
ICS874S02BMI REV. AOCTOBER 16, 2008  
ICS874S02I  
1:1 DIFFERENTIAL-TO-LVDS ZERO DELAY CLOCK GENERATOR  
Reliability Information  
Table 8. θJA vs. Air Flow Table for a 20 Lead SOIC  
θJA by Velocity  
Linear Feet per Minute  
0
200  
500  
Multi-Layer PCB, JEDEC Standard Test Boards  
64.7°C/W  
56.7°C/W  
53.5°C/W  
Transistor Count  
The transistor count for ICS874S02I is: 1358  
Package Outline and Package Dimensions  
Package Outline - M Suffix for 20 Lead SOIC  
Table 9. Package Dimensions for 20 Lead SOIC  
300 Millimeters  
All Dimensions in Millimeters  
Symbol  
Minimum  
Maximum  
N
A
A1  
A2  
B
C
D
E
20  
2.65  
0.10  
2.05  
0.33  
0.18  
12.60  
7.40  
2.55  
0.51  
0.32  
13.00  
7.60  
e
1.27 Basic  
H
h
10.00  
0.25  
0.40  
0°  
10.65  
0.75  
1.27  
8°  
L
α
Reference Document: JEDEC Publication 95, MS-013, MS-119  
IDT™ / ICS™ LVDS CLOCK GENERATOR  
14  
ICS874S02BMI REV. AOCTOBER 16, 2008  
ICS874S02I  
1:1 DIFFERENTIAL-TO-LVDS ZERO DELAY CLOCK GENERATOR  
Ordering Information  
Table 10. Ordering Information  
Part/Order Number  
874S02BMI  
874S02BMIT  
874S02BMILF  
874S02BMILFT  
Marking  
Package  
20 Lead SOIC  
20 Lead SOIC  
Shipping Packaging  
Tube  
1000 Tape & Reel  
Tube  
Temperature  
-40°C to 85°C  
-40°C to 85°C  
-40°C to 85°C  
-40°C to 85°C  
ICS874S02BMI  
ICS874S02BMI  
ICS874S02BMILF  
ICS874S02BMILF  
Lead-Free, 20 Lead SOIC  
Lead-Free, 20 Lead SOIC  
1000 Tape & Reel  
While the information presented herein has been checked for both accuracy and reliability, Integrated Device Technology (IDT) assumes no responsibility for either its use or for  
the infringement of any patents or other rights of third parties, which would result from its use. No other circuits, patents, or licenses are implied. This product is intended for use  
in normal commercial and industrial applications. Any other applications, such as those requiring high reliability or other extraordinary environmental requirements are not  
recommended without additional processing by IDT. IDT reserves the right to change any circuitry or specifications without notice. IDT does not authorize or warrant any IDT  
product for use in life support devices or critical medical instruments.  
IDT™ / ICS™ LVDS CLOCK GENERATOR  
15  
ICS874S02BMI REV. AOCTOBER 16, 2008  
ICS874S02I  
1:1 DIFFERENTIAL-TO-LVDS ZERO DELAY CLOCK GENERATOR  
Contact Information:  
www.IDT.com  
Corporate Headquarters  
Sales  
Technical Support  
Integrated Device Technology, Inc.  
800-345-7015 (inside USA)  
+408-284-8200 (outside USA)  
Fax: 408-284-2775  
netcom@idt.com  
+480-763-2056  
6024 Silver Creek Valley Road  
San Jose, CA 95138  
United States  
800-345-7015 (inside USA)  
+408-284-8200 (outside USA)  
www.IDT.com/go/contactIDT  
© 2008 Integrated Device Technology, Inc. All rights reserved. Product specifications subject to change without notice. IDT and the IDT logo are trademarks of Integrated Device  
Technology, Inc. Accelerated Thinking is a service mark of Integrated Device Technology, Inc. All other brands, product names and marks are or may be trademarks or registered  
trademarks used to identify products or services of their respective owners.  
www.IDT.com  
Printed in USA  

相关型号:

ICS874S336AG

PLL Based Clock Driver, 874S Series, 1 True Output(s), 0 Inverted Output(s), PDSO24, 4.40 X 7.80 MM, 0.925 MM HEIGHT, TSSOP-24
IDT

ICS874S336AGLFT

PLL Based Clock Driver, 874S Series, 1 True Output(s), 0 Inverted Output(s), PDSO24, 4.40 X 7.80 MM, 0.925 MM HEIGHT, LEAD FREE, TSSOP-24
IDT

ICS874S336AGT

PLL Based Clock Driver, 874S Series, 1 True Output(s), 0 Inverted Output(s), PDSO24, 4.40 X 7.80 MM, 0.925 MM HEIGHT, TSSOP-24
IDT

ICS8752

LOW SKEW, 1-TO-8 LVCMOS CLOCK MULTIPLIER/ZERO DELAY BUFFER
ICSI

ICS8752

LOW SKEW, 1-TO-8 LVCMOS CLOCK MULTIPLIER/ZERO DELAY BUFFER
IDT

ICS8752BYLF

Low Skew Clock Driver, 8 True Output(s), 0 Inverted Output(s), CMOS, PQFP32, 7 X 7 MM, 1.40 MM HEIGHT, 0.80 MM PITCH, MS-026, LQFP-32
IDT

ICS8752BYT

Low Skew Clock Driver, 8 True Output(s), 0 Inverted Output(s), CMOS, PQFP32, 7 X 7 MM, 1.40 MM HEIGHT, 0.80 MM PITCH, MS-026, LQFP-32
IDT

ICS8752CY

LOW SKEW, 1-TO-8 LVCMOS CLOCK MULTIPLIER/ZERO DELAY BUFFER
ICSI

ICS8752CYI

PLL Based Clock Driver, 8752 Series, 8 True Output(s), 0 Inverted Output(s), CMOS, PQFP32, 7 X 7 MM, 1.40 MM HEIGHT, MS-026, LQFP-32
IDT

ICS8752CYILFT

暂无描述
IDT

ICS8752CYIT

PLL Based Clock Driver, 8752 Series, 8 True Output(s), 0 Inverted Output(s), CMOS, PQFP32, 7 X 7 MM, 1.40 MM HEIGHT, MS-026, LQFP-32
IDT

ICS8752CYLF

PLL Based Clock Driver, 8752 Series, 8 True Output(s), 0 Inverted Output(s), CMOS, PQFP32, 7 X 7 MM, 1.40 MM HEIGHT, ROHS COMPLIANT, MS-026, LQFP-32
IDT