The Fairchild/ON Semiconductor 001664-HMHA2801R1V is an SMD (SMT) mounting type transistor output optocoupler. It has a forward voltage of 1.3V (Max) and an isolation voltage of 3750Vrms. The maximum output voltage is 80V, and the channel output current is 50mA. This optocoupler has a minimum DC current transfer ratio of 80% at 5mA and a maximum DC current transfer ratio of 600% at 5mA. The switching turn-on and turn-off time is not specified, while the rise and fall time is 3μs and 3μs respectively. The package type is 4-Mini-Flat, and the temperature range for operating is -55°C to 100°C. This optocoupler is categorized under isolators and is now obsolete (EOL). It is used in power management, signal processing, and industrial applications.