ICS9147-16 Datasheet, PDF (1/6 Pages) Integrated Circuit Systems – Frequency Generator & Integrated Buffers for PENTIUMTM

Integrated
Circuit
Systems, Inc.
ICS9147-16
Frequency Generator & Integrated Buffers for PENTIUM^TM
General Description
The ICS9147-16 generates all clocks required for high
speed RISC or CISC microprocessor systems such as Intel
PentiumPro. Two different reference frequency multiplying
factors are externally selectable with smooth frequency
transitions. Glitch-free Stop clock control is provided for
CPU and BUS clocks. Complete chip low current mode is
achieved with the Power Down# pin.
High drive BUS outputs typically provide greater than 1 V/
ns slew rate into 30 pF loads. CPU outputs typically provide
better than 1V/ns slew rate into 20 pF loads while
maintaining 50±5% duty cycle. The REF and IOAPIC clock
outputs typically provide better than 0.5V/ns slew rates.
Separate buffer supply pins VDDL allow for nominal 3.3V
voltage or reduced voltage swing (from 2.9 to 2.5V) for
CPU (1:4) and IOAPIC outputs.
Features
• Generates four processor, eight bus, four 14.31818
MHz, two 48 MHz clocks for USB support.
• CPU to BUS clock skew 1 to 4ns (CPU early)
• Synchronous clocks skew matched to 250ps window on
CPU and 500ps window on BUS.
• Selectable multiplying ratios
• Glitch free stop clock controls CPUEN and BUSEN
• 3.0V – 3.7V supply range, 2.5V to VDD supply range for
CPU (1:4) clocks and IOAPIC clock.
• 48-pin SSOP package
Pin Configuration
Block Diagram
9147-16 Rev A 072897P
48-Pin SSOP
Pentium is a trademark of Intel 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.