Isocom, 4N31SMT&R Optocoupler. Mounting Type: Surface Mount. Output Device: Phototransistor. Maximum Forward Voltage: 1.5V. Number of Pins: 6. Package Type: DIP. Input Current Type: DC. Typical Rise Time: 5µs. Maximum Input Current: 80 mA. Isolation Voltage: 5.3 kVrms, 7500 V Pk. Typical Fall Time: 40µs.