2001-04-17

Page

1

MDST-0003-03

www.vaishali.com

Vaishali Semiconductor

747 Camden Avenue, Suite C

Campbell

CA 95008

Ph. 408.377.6060

Fax 408.377.6063

Applications

•= Set-top boxes

•= Telecom switching

•= HDTV

•= MPEG Video clock source

General Description

The Vaishali VT83027 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 13.5 MHz, 14 pF (pull

range of 200 ppm) crystal input, and produce a 27 MHz output. A 0 to 3V control signal is used to fine tune

the output clock frequency in the ±100ppm range.

Features

•= 3.3V supply operation

•= Low jitter PLL Clock Synthesizer

−= Zero ppm synthesis error

•= Uses inexpensive pullable crystal

•= On-chip oscillator with 200 ppm pull

range (±100 ppm)

•= 8 pin SOIC package

VT83027

27MHz, 3.3V VCXO

(Voltage-Controlled Crystal Oscillator)

Figure 1. Functional Block Diagram

CLK1

VDD2

X2

Load Cap

Control

Low

Phase

Noise

PLL

Output

Buffer

osc

VDD1

13.5 MHz

Pullable

Crystal

VIN

X1

GND1

GND2

Load

Caps

8 pin (150 mil) SOIC

VT83027

X1

X2

VDD1

VIN

GND2

CLK

1

2

3

4

5

6

7

8

GND1

VDD2

Figure 2. Pin Configuration