ICS9158-05 Datasheet, PDF (1/7 Pages) Integrated Circuit Systems – Buffered Clock Generator for Pentium™ /Triton™ Systems

Integrated
Circuit
Systems, Inc.
ICS9158-05
Advanced Information
Buffered Clock Generator for Pentium™ /Triton™ Systems
General Description
The ICS9158-05 is a low cost frequency generator designed
specifically to clock Pentium systems using the Triton chip
set. Three copies of the CPU clock are available at 50, 60, or
66.7 MHz. Five copies of the synchronous BUS clock run at
half the CPU frequency. A 14.318 MHz REFCLK, 12 MHz,
KEYBD, and 24 MHz FLOPPY clock are also provided.
Each high drive output is capable of driving a 30pF load with
better than 1V/ns typical slew and have a duty cycle of 50±5%.
The synchronous outputs are skew controlled to within±250ps
and CPU clocks lead BUS clocks by 2-5ns.
Glitch-free start and stop of the CPU and BUS clocks is
provided as well as a power-down mode with all clocks forced
low and the internal oscillators and PLLs powered-down.
Power-up time is less than 10ns. All frequency transitions are
gradual and meet the Intel cycle-to-cycle timing specification
for 486 and Pentium microprocessors.
Features
• 3 CPU and 5 synchronous BUS clocks
• 50/60/66 MHz and glitch-free stop clock selections
• ±250ps skew between all synchronous outputs
• Outputs drive up to 30pF load with 1V/ns slew
• 2-5ns early CPU clocks support Triton chip set
• Compatible with 486 and Pentium CPUs
• Consumes less than 10µA in power-down mode
• On-chip loop filter components
• 3.0V - 5.5V supply range
• 24-pin SOIC package
Applications
• Ideal for RISC or CISC systems such as 486, Pentium,
PowerPC,™ etc. requiring multiple CPU and
synchronous BUS clocks.
Block Diagram
9158-05 Rev B 05/08/97
Pentium and Triton are trademarks of Intel Corporation.
PowerPC is a trademark of Motorola Corporation
ADVANCE INFORMATION documents contain information on
new products in the sampling or preproduction phase of devel-
opment. Characteristic data and other specifications are subject to
change without notice.