Isocom, ISP844XSM Phototransistor Output Dual Optocoupler, Surface Mount, 4-Pin SMD. Maximum Forward Voltage: 1.4V. Number of Channels: 2. Typical Rise Time: 4µs. Maximum Input Current: 50 (Forward) mA. Isolation Voltage: 3.75 kVrms, 5300 V Pk. Maximum Current Transfer Ratio: 3.0. Minimum Current Transfer Ratio: 0.2. Typical Fall Time: 3µs.