BROADCOM HCPL-4200-000E

The HCPL-4200-000E is a 1-channel 8-pin Optically Coupled Optocoupler designed to operate as a receiver in equipment using the 20mA current loop. 20mA current loop systems conventionally signal a logic high state by transmitting 20mA of loop current and signal a logic low state by allowing no more than a few milliamperes of loop current. Optical coupling of the signal from the 20mA current loop to the logic output breaks ground loops and provides for a very high common mode rejection. It 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 interface and providing guaranteed common mode rejection. The buffer circuit on its current loop side provides typically 0.8mA of hysteresis which increases the immunity to common mode and differential mode noise.