TLF5968

November 1995

CD4046BMCD4046BC Micropower Phase-Locked Loop

General Description

The CD4046B micropower phase-locked loop (PLL) con-

sists of a low power linear voltage-controlled oscillator

(VCO) a source follower a zener diode and two phase

comparators The two phase comparators have a common

signal input and a common comparator input The signal

input can be directly coupled for a large voltage signal or

capacitively coupled to the self-biasing amplifier at the sig-

nal input for a small voltage signal

Phase comparator I an exclusive OR gate provides a digital

error signal (phase comp I Out) and maintains 90 phase

shifts at the VCO center frequency Between signal input

and comparator input (both at 50% duty cycle) it may lock

onto the signal input frequencies that are close to harmon-

ics of the VCO center frequency

Phase comparator II is an edge-controlled digital memory

network It provides a digital error signal (phase comp II

Out) and lock-in signal (phase pulses) to indicate a locked

condition and maintains a 0 phase shift between signal in-

put and comparator input

The linear voltage-controlled oscillator (VCO) produces an

output signal (VCO Out) whose frequency is determined by

is used with an external resistor of 10 kX or more

The INHIBIT input when high disables the VCO and source

follower to minimize standby power consumption The zener

diode is provided for power supply regulation if necessary

Features

Y

Wide supply voltage range

30V to 18V

Y

Low dynamic

70 mW (typ) at

power consumption

Y

VCO frequency

Y

Low frequency drift

with temperature

Y

High VCO linearity

1% (typ)

Applications

Y

FM demodulator and modulator

Y

Frequency synthesis and multiplication

Y

Frequency discrimination

Y

Data synchronization and conditioning

Y

Voltage-to-frequency conversion

Y

Tone decoding

Y

FSK modulation

Y

Motor speed control

Block

Connection Diagrams

TLF5968 – 1

FIGURE 1

Dual-In-Line Package

TLF5968 – 2

Top View

Order Number CD4046B

C1995 National Semiconductor Corporation

RRD-B30M115Printed in U S A