AV9155C Datasheet, PDF (1/14 Pages) Integrated Circuit Systems – Low Cost 20-Pin Frequency Generator

Integrated
Circuit
Systems, Inc.
AV9155C
Low Cost 20-Pin Frequency Generator
General Description
The AV9155C is a low cost frequency generator designed
specifically for desktop and notebook PC applications with
either 3.3V or 5.0V power supply voltage. Its CPU clocks
provide all necessary CPU frequencies for 286, 386 and 486
systems, including support for the latest speeds of processors.
The device uses a 14.318 MHz crystal to generate the CPU
and all peripheral clocks for integrated desktop motherboards.
The dual 14.318 MHz clock outputs allows one output for the
system and one to be the input to an ICS graphics frequency
generator such as the AV9194.
The CPU clock offers the unique feature of smooth, glitch-
free transitions from one frequency to the next, making this
ideal device to use whenever slowing the CPU speed. The
AV9155C makes a gradual transition between frequencies, so
that it obeys the Intel cycle-to-cycle timing specification for
486 systems. The simultaneous 2X and 1X CPU clocks offer
controlled skew to within 1.5ns (max) of each other.
ICS offers several versions of the AV9155C. The different
devices are shown below:
Features
• Compatible with 286, 386, and 486 CPUs
• Supports turbo modes
• Generates communications clock, keyboard clock,
floppy disk clock, system reference clock, bus clock
and CPU clock
• Output enable tristates outputs
• Up to 100 MHz at 5V or 3.3V
• 20-pin DIP or SOIC
• All loop filter components internal
• Skew-controlled 2X and 1X CPU clocks
• Power-down option
ICS has been shipping motherboard frequency generators
since April 1990, and is the leader in the area of multiple
output clocks on a single chip. The AV9155C is a third
generation device, and uses ICS’s patented analog CMOS
phase-locked loop technology for low phase jitter. ICS offers
a broad family of frequency generators for motherboards,
graphics and other applications, including cost-effective
versions with only one or two output clocks. Consult ICS for
all of your clock generation needs.
PART
AV9155C-01
AV9155C-02
AV9155C-23
AV9155C-36
DESCRIPTION
Motherboard clock generator with 16 MHz BUS CLK
Motherboard clock generator with 32 MHz BUS CLK
Ô Includes Pentium frequencies
Features a special 40 MHz SCSI clock
Block Diagram
AV9155C Rev F 12/13/00
Pentium is a trademark of Intel Corporation.