©2005 Fairchild Semiconductor Corporation

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HCPL3700 Rev. 1.0.3

August 2008

HCPL3700

AC/DC to Logic Interface Optocoupler

Features

■ AC or DC input

■ Programmable sense voltage

■ Logic level compatibility

■ Threshold guaranteed over temperature (0°C to 70°C)

■ Optoplanar™ construction for high common mode

immunity

■ UL recognized (file # E90700)

■ VDE certified – ordering option ‘V’, e.g., HCPL3700V

Applications

■ Low voltage detection

■ 5 V to 240 V AC/DC voltage sensing

■ Relay contact monitor

■ Current sensing

■ Microprocessor Interface

■ Industrial controls

Description

The HCPL-3700 voltage/current threshold detection

optocoupler consists of an AlGaAs LED connected to a

threshold sensing input buffer IC which are optically cou-

pled to a high gain darlington output. The input buffer

chip is capable of controlling threshold levels over a wide

range of input voltages with a single resistor. The output

is TTL and CMOS compatible.

Schematics

Package Outlines

8

1

8

1

8

1

1

2

3

45

8

6

7

AC

DC+

DC-

AC

GND

V

NC

VO

CC

AC/DC

POWER

LOGIC

RX

HCPL-3700

GND 1

GND 2

TRUTH TABLE

(Positive Logic)

A 0.1µF bypass capacitor must be connected

between pins 8 and 5.

Input

Output

HL

LH