HCPL-4100

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 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 t...