onsemi, HCPL3700VM CMOS Output Optocoupler, Through Hole, 8-Pin DIP

The HCPL3700M voltage/current threshold detection optocoupler consists of an AlGaAs LED connected to a threshold sensing input buffer IC which are optically coupled to a high gain darlington output. The input buffer chip is capable of controlling threshold levels over a wide range of input voltages with a single resistor. The output is TTL and CMOS compatible.

AC or DC Input
Programmable Sense Voltage
Logic Level Compatibility
Threshold Guaranteed Over Temperature (0°C to 70°C)
Applications
Low Voltage Detection
5 V to 240 V AC/DC Voltage Sensing
Relay Contact Monitor
Current Sensing
Microprocessor Interface
Industrial Controls