ICS9179-06 Datasheet, PDF (1/8 Pages) Integrated Circuit Systems – Zero Delay Buffers

Integrated
Circuit
Systems, Inc.
ICS9179 - 06
Zero Delay Buffers
General Description
The ICS9179-06 generates low skew clock buffers required
for high speed RISC or CISC microprocessor systems such as
Intel PentiumPro. An output enable is provided for testability.
The device is a buffer with low output to output skew. This is
a zero delay buffer device, using an internal PLL. This buffer
can be used for phase synchronization to a master clock. With
the wide PLL loop BW, this buffer is compatible to Spread
Spectrum input clocks from clock generator products such as
the ICS9148-27.
The individual clock outputs are addressable through I²C to be
enabled, or stopped in a low state for reduced EMI when the
lines are not needed. The device defaults to zero-delay mode,
but can be programmed with I²C for selectable delays -2.7,
+2.0, -0.7 ns (nominal target values).
Block Diagram
Features
• Zero delay buffer, 16 outputs
• Supports up to four SDRAM DIMMS
• Wide PLL loop bandwidth makes this part ideal in
Spread Spectrum applications.
• Skew Input to FB_IN ±250ps default, with selectable
skew -2.7, +2.0, -0.7ns nominal.
• Synchronous clocks skew matched to 250 ps window on
output.
• 33 to 133MHz input or output frequency.
• I²C Serial Configuration interface to allow individual
clocks to be stopped, or selectable delays.
• Multiple VDD, VSS pins for noise reduction
• Slew rate 1.5V/ns into 30pF.
• VDD = 3.3 ±5%, 0 to 70°C
• All outputs (0:15) tristate with OE low
(FB_OUT stays running).
• 48-Pin SSOP package
Pin Configuration
Functionality
OE#
OUTPUT
(0:15)
0
Hi-Z
1
1 X INPUT
FB_OUT
1 X INPUT
1 X INPUT
9179-06 Rev F 6/22/99
48-Pin SSOP
PentiumPro is a trademark of Intel Corporation
I²C is a trademark of Philips Corporation
ICS reserves the right to make changes in the device data identified in
this publication without further notice. ICS advises its customers to
obtain the latest version of all device data to verify that any
information being relied upon by the customer is current and accurate.