Voltage-to-Frequency

and Frequency-to-Voltage

CONVERTER

FEATURES

q HIGH LINEARITY: 12 to 14 bits

q V/F OR F/V CONVERSION

q 6-DECADE DYNAMIC RANGE

q GAIN DRIFT: 20ppm/

q OUTPUT TTL/CMOS COMPATIBLE

APPLICATIONS

q INEXPENSIVE A/D AND D/A CONVERTER

q DIGITAL PANEL METERS

q TWO-WIRE DIGITAL TRANSMISSION WITH

NOISE IMMUNITY

q FM MOD/DEMOD OF TRANSDUCER

SIGNALS

q PRECISION LONG TERM INTEGRATOR

q HIGH RESOLUTION OPTICAL LINK FOR

ISOLATION

q AC LINE FREQUENCY MONITOR

q MOTOR SPEED MONITOR AND CONTROL

Comparators

–7.5V Ref

Flip-

flop

Common

f

OUT

f

IN

One-shot

V

OUT

+V

CC

–In

+In

–V

CC

C

1

DESCRIPTION

The VFC320 monolithic voltage-to-frequency and frequency-to-

voltage converter provides a simple low cost method of convert-

ing analog signals into digital pulses. The digital output is an

open collector and the digital pulse train repetition rate is propor-

tional to the amplitude of the analog input voltage. Output pulses

are compatible with TTL, and CMOS logic families.

High linearity (0.005%, max at 10kHz FS) is achieved with

relatively few external components. Two external resistors and

two external capacitors are required to operate. Full scale fre-

quency and input voltage are determined by a resistor in series

with –In and two capacitors (one-shot timing and input amplifier

integration). The other resistor is a non-critical open collector

mance grades. The VFC320 is specified for the –25

°C to +85°C,

range.

VFC320

SBVS017A – AUGUST 2001

www.ti.com

PRODUCTION DATA information is current as of publication date.

Products conform to specifications per the terms of Texas Instruments

standard warranty. Production processing does not necessarily include

testing of all parameters.

Copyright © 1982, Texas Instruments Incorporated

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of

Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

VFC320