MK3720

27 MHz and 54 MHz 3.3 Volt VCXO

MDS 3720 D

1

Revision 053100

Printed 11/16/00

Integrated Circuit Systems, Inc. •525 Race Street • San Jose • CA• 95126• (408)295-9800tel • www.icst.com

Block Diagram

Description

Features

The MK3720 is a low cost, low jitter, high

performance 3.3 Volt VCXO and PLL clock

synthesizer designed to replace expensive 13.5, 27,

or 54MHz VCXOs. The patented on-chip

Voltage Controlled Crystal Oscillator accepts a

0 to 3.3 V input voltage to cause the output clocks

to vary by ±100 ppm. Using our patented VCXO

and analog/digital Phase-Locked Loop (PLL)

techniques, the device uses an inexpensive external

13.5 MHz pullable crystal input to produce output

clocks of 13.5 MHz, 27 MHz, and 54 MHz .

The MK3720A is a drop-in replacement to the

earlier MK3720S.

• Packaged in 8 pin SOIC

• 3.3 V only operating voltage

• Output clocks of 54, 27, and 13.5MHz

• Uses an inexpensive 13.500 MHz external crystal

• On-chip patented VCXO with pull range

of 200ppm (minimum)

• VCXO tuning voltage of 0 to 3.3 V

• 12 mA output drive capability at TTL levels

• Advanced, low power, sub-micron CMOS process

• The A version is the latest, manufactured in a smaller

geometry process. The MK3720A gives a wider pull

range than the MK3720S, and so is recommended

for all new designs, and cost reductions of existing

designs.

Voltage

Controlled

Crystal

Oscillator

PLL/Clock

Synthesis

Circuitry

13.5 MHz

pullable

crystal

X1

X2

VIN

Output

Buffer

54 MHz Clock

Output

Buffer

13.5 MHz Clock

Output

Buffer

27 MHz Clock