Features

x Data output compatible with LSTTL, TTL and CMOS

x 20 K Baud data rate at 1400 metres line length

x Guaranteed On and Off thresholds

x LED is protected from excess current

x Input threshold hysteresis

x Three-state output compatible with data buses

x Internal shield for high Common Mode Rejection

x Safety approval

UL recognized -3750 V rms, for 1 minute

CSA approved

x Optically coupled 20 mA current loop transmitter,

HCPL-4100, also available

Applications

x Isolated 20 mA current

x Loop receiver in:

Computer peripherals

Industrial control equipment

Data communications equipment

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

Description

The HCPL-4200 optocoupler is designed to operate as a

receiver 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 cou-

pling of the signal from the 20 mA current loop to the

logic output breaks ground loops and provides for a very

high common mode rejection. The HCPL-4200 aids in the

design process by providing guaranteed thresholds for

logic high state and logic low state for the current loop,

providing an LSTTL, TTL, or CMOS compatible logic in-

terface, and providing guaranteed common mode re-

jection. The buffer circuit on the current loop side of the

HCPL-4200 provides typically 0.8 mA of hysteresis which

increases the immunity to common mode and differen-

tial mode noise. The buffer also provides a controlled

amount of LED drive current which takes into account

any LED light output degradation. The internal shield al-

lows a guaranteed 1000 V/μs common mode transient

immunity.

Functional Diagram

HCPL-4200

Optically Coupled 20 mA Current Loop Receiver

Data Sheet

Lead (Pb) Free

RoHS 6 fully

compliant

RoHS 6 fully compliant options available;

-xxxE denotes a lead-free product

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.