ICS9158-04 Datasheet, PDF (1/4 Pages) Integrated Circuit Systems – Frequency Generator and Integrated Buffer

Integrated
Circuit
Systems, Inc.
ICS9158-04
Frequency Generator and Integrated Buffer
General Description
The ICS9158-04 is a low cost frequency generator designed
specifically for desktop and notebook PC applications. Up to
six copies of the CPU clock are available, and five or six
copies of the BUS clock are available depending on the status
of the frequency select pins, which eliminates the need for an
external buffer.
Each high drive (25mA) output is capable of driving a 30pF
load and has a typical duty cycle of 50/50. The clock outputs
are skew controlled to within ±250ps.
The ICS9158-04 makes a gradual transition between
frequencies, so that it meets the Intel cycle-to-cycle timing
specification for 486 and Pentium™ systems.
Block Diagram
Features
• 11 skew-free, high drive CPU/BUS clocks
• Up to 66 MHz at 3.3V
• ±250ps skew between all outputs
• Outputs can drive up to 30pF load and 25mA
• 50±10% duty cycle
• Compatible with 486 and Pentium CPUs
• Selectable 5/6 or 6/5 CPU/BUS output ratio
• 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 BUS
clocks.
9158-04 RevC 8/10/98
Pentium is a trademark of Intel Corporation.
PowerPC is a trademark of Motorola Corporation.
NOTE: THIS DATA SHEET, ICS9158-04, IS AN ADDENDUM TO THE EXISTING
ICS9158 DATA SHEET. ALL INFORMATION IN THIS DATA SHEET SUPERSEDES THE
DATA FOUND IN THE ORIGINAL ICS9158 DATA SHEET.
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.