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.

Features
• Guaranteed 20 mA loop parameters
• Data input compatible with LSTTL, TTL and CMOS Logic
• Internal shield for High Common Mode rejection
• 20 kBaud data rate at 400 metres line length
• Guaranteed On and Off output current levels
• Safety approval UL Recognized -3750 V rms for 1 minute CSA Approved
• Optically coupled 20 mA current loop receiver, HCPL-4200, also available

Applications
• Isolated 20 mA current loop transmitter in: Computer peripherals Industrial control equipment Data communications equipment