Integrated

Circuit

Systems, Inc.

ICS1567

Differential Output Video Dot Clock Generator

General Description

The ICS1567 is a very high performance monolithic PLL

frequency synthesizer. Utilizing ICS’s advanced CMOS

mixed-mode technology, the ICS1567 provides a low cost

solution for high-end video clock generation, and for telecom

system clock generation.

The ICS1567 has differential video clock outputs (CLK and

CLK) that are compatible with industry standard video DACs

& RAMDACs. An additional clock output, LD, is provided,

whose frequency is divided down from the main clock by a

programmable divider.

Operating frequencies are selectable from a pre-programmed

(customer-defined) table. An on-chip crystal oscillator for gen-

erating the reference frequency is provided on the ICS1567.

Programming of the ICS1567 is accomplished via frequency

select pins on the package. The ICS1567 has five lines plus a

STROBE pin which permits selection of 32 frequencies. Reset

of the pipeline delay on Brooktree RAMDACs is automatically

performed on a rising edge of the STROBE line.

Features

•• High frequency operation for extended video modes - up

to 180 MHz

•• Compatible with Brooktree high performance RAMDACs

a)

Differential output clocks with ECL logic levels

b) Programmable divider modulus for load clock

c)

Circuitry included for automatic reset of Brooktree

RAMDAC pipeline delay

•• Low cost - eliminates need for multiple ECL crystal clock

oscillators in video display systems

•• Strobed/Transparent frequency select options

•• 32-user selected mask-programmable frequencies

•• Fast acquisition of selected frequencies, strobed or non-

strobed

•• Advanced PLL for low phase-jitter

•• Dynamic control of VCO sensitivity providing optimized

loop gain over entire frequency range

•• Small footprint - 16-pin wide body (300 mil) SOIC

FS0

1

16

FS1

XTAL1

2

15

FS2

XTAL2

3

14

FS3

STROBE

4

13

VDD

VSS

5

12

VDDO

VSS

6

11

VDDO

LD

7

10

CLK

FS4

8

9

CLK

Pin Configuration

ICS1567RevB090894

Applications

•• Workstations

•• High-resolution PC and MAC displays

•• 8514A - TMS340X0 systems

•• EGA - VGA - Super VGA video

•• Telecom reference clock generation - suitable for Sonet,

ATM and other data rates up to 155.52Mb.

16-Pin SOIC