91857AGLF IDT, 91857AGLF Datasheet - Page 2

• Manufacturer Part Number: 91857AGLF
• Description: Clock Drivers & Distribution
• Manufacturer: IDT

Specifications of 91857AGLF

• Product Category: Clock Drivers & Distribution
• Rohs: yes
• Part # Aliases: ICS91857AGLF

Pin Descriptions
ICS91857
This PLL Clock Buffer is designed for a V
ICS91857 is a zero delay buffer that distributes a differential clock input pair (CLK_INC, CLK_INT) to ten differential
pair of clock outputs (CLKT[0:9], CLKC[0:9]) and one differential pair feedback clock output (FB_OUT, FB_OUTC). The
clock outputs are controlled by the input clocks (CLK_INC, CLK_INT), the feedback clocks (FB_INT, FB_INC) the 2.5-
V LVCMOS input (PD#) and the Analog Power input (AV
are disabled, the PLL is turned off and the differential clock outputs are Tri-Stated. When AV
is turned off and bypassed for test purposes.
When the input frequency is less than the operating frequency of the PLL, appproximately 20MHz, the device will
enter a low power mode. An input frequency detection circuit on the differential inputs, independent from the input
buffers, will detect the low frequency condition and perform the same low power features as when the (PD#) input
is low. When the input frequency increases to greater than approximately 20 MHz, the PLL will be turned back on,
the inputs and outputs will be enabled and PLL will obtain phase lock between the feedback clock pair (FB_INT,
FB_INC) and the input clock pair (CLK_INC, CLK_INT).
The PLL in the ICS91857 clock driver uses the input clocks (CLK_INC, CLK_INT) and the feedback clocks (FB_INT,
FB_INC) provide high-performance, low-skew, low-jitter output differential clocks (CLKT [0:9], CLKC [0:9]). The
ICS91857 is also able to track Spread Spectrum Clock (SSC) for reduced EMI.
ICS91857 is characterized for operation from 0°C to 70°C and will meet JEDEC Standard 82-1 and 82-1A for Registered
DDR Clock Driver.
0494C—08/15/05
2
2
, 1
, 4
, 7
, 6
I P
2
2
3
2
, 7
, 2
, 8
1
, 1
, 3
N
2
3
, 1
, 8
, 9
, 0
2
3
1
4
N
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1
, 4
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3
4
1
1
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3
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4
, 9
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, 6
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, 4
, 5
4
4
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2
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2
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4
4
2
3
, 1
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, 7
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