The IL410 is a high dV/dt low input current PhotoTRIAC Output Optocoupler consists of a GaAs IRLED optically coupled to a photosensitive zero crossing TRIAC network. High input sensitivity is achieved by using an emitter follower phototransistor and a cascaded SCR pre-driver resulting in an LED trigger current of less than 2mA (DC). The use of a proprietary dV/dt clamp results in a static dV/dt of greater than 10kV/ms. This clamp circuit has a MOSFET that is enhanced when high dV/dt spikes occur between MT1 and MT2 of the TRIAC. When conducting, the FET clamps the base of the phototransistor, disabling the first stage SCR pre-driver. The zero cross line voltage detection circuit consists of two enhancement MOSFETS and a photodiode. Once the main voltage can enable the N-channel, it clamps the base of the phototransistor, disabling the first stage SCR pre-driver.
