Features

x Guaranteed 20 mA loop parameters

x Data input compatible with LSTTL, TTL and CMOS

Logic

x Internal shield for High Common Mode rejection

x 20 kBaud data rate at 400 metres line length

x Guaranteed On and Off output current levels

x Safety approval

UL Recognized -3750 V rms for 1 minute

CSA Approved

x Optically coupled 20 mA current loop receiver,

HCPL-4200, also available

Applications

x Isolated 20 mA current loop transmitter in:

Computer peripherals

Industrial control equipment

Data communications equipment

CAUTION: It is advised that normal static precautions be taken in handling and assembly

of this component to prevent damage and/or degradation which may be induced by ESD.

A 0.1 μF bypass capacitor connected between pins 8 and 5 is recommended.

Description

The HCPL-4100 optocoupler is designed to operate as a

transmitter in equipment using the 20 mA current loop.

20 mA current loop systems conventionally signal a

logic high state by transmitting 20 mA of loop current

(MARK), and signal a logic low state by allowing no

more than a few milliamperes of loop current (SPACE).

Optical coupling of the signal from the logic input to the

20 mA current loop breaks ground loops and provides

very high immunity to common mode interference.

The

HCPL-4100

data

input

is

compatible

with

LSTTL, TTL, or CMOS logic gates. The input integrated

circuit drives a GaAsP LED. The light emitted by the LED is

sensed by a second integrated circuit that allows 20 mA

to pass with a voltage drop of less than 2.7 volts when

no light is emitted and allows less than 2 mA to pass

when light is emitted. The transmitter output is capable

of withstanding 27 volts. The input integrated circuit

provides a controlled amount of LED drive current and

takes into account any LED light output degradation. The

internal shield allows a guaranteed 1000 V/μs common

mode transient immunity.

Functional Diagram

HCPL-4100

Optically Coupled 20 mA Current Loop Transmitter

Data Sheet

Lead (Pb) Free

RoHS 6 fully

compliant

RoHS 6 fully compliant options available;

-xxxE denotes a lead-free product