2001-04-12

Page

1

MDST-0011-01

www.vaishali.com

Vaishali Semiconductor

747 Camden Avenue, Suite C

Campbell

CA 95008

Ph. 408.377.6060

Fax 408.377.6063

Applications

•= DSL clock source

•= Set-top boxes

•= Telecom switching

•= MPEG Video clock source

•= HDTV

General Description

The Vaishali VT83201 is a single-chip, integrated VCXO and Phase Locked Loop (PLL) clock synthesizer.

The device uses the VCXO and an analog Phase-Locked Loop (PLL) to accept a 10 MHz to 20 MHz, 30pF

(pull range of 200 ppm) crystal input, in order to produce either one or two output clocks. A 0 to 3V control

signal is used to fine tune the output clock frequency in the ±100ppm range. Select inputs S0 and S1 are

used for frequency and output selection.

Features

•= 3.3V supply operation

•= Packaged in 16-pin SOIC package

•= Replaces separate VCXO and multiplier

•= Uses inexpensive pullable crystal

•= On-chip VCXO with 200 ppm pull range (±100 ppm)

•= 5V-tolerant control inputs

•= Zero ppm synthesis error in both

clocks

VT83201

3.3V Low Phase Noise VCXO

(Voltage-Controlled Crystal Oscillator)

and PLL Clock Synthesizer

Figure 1. Functional Block Diagram

CLK1

CLK2

VDD1

VDD2

X2

Load Cap Control

Low

Phase

Noise

PLL

Output

Buffer

Output

Buffer

osc

Load

Caps

OE

10-20 MHz

Pullable

Crystal

S1:S0

VIN

X1