BROADCOM HCPL-4100-000E

The HCPL-4100-000E is a 1-channel 8-pin optically coupled Optocoupler designed to operate as a transmitter in equipment using the 20mA current loop. 20mA current loop systems conventionally signal a logic high state by transmitting 20mA 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 20mA current loop breaks ground loops and provides very high immunity to common mode interference. The 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 20mA to pass with a voltage drop of less than 2.7V when no light is emitted and allows less than 2mA to pass when light is emitted. The transmitter output is capable of withstanding 27V.