The Gate Trigger Current (I_GT) of a Gate Turn-Off (GTO) thyristor is the minimum current required to turn on the device when a gate voltage is applied. This parameter is critical as it defines the current level required to initiate the transition from the off state to the on state. Selecting the appropriate gate trigger current is essential to ensure that the GTO functions reliably and effectively across different circuit applications. Engineers must consider the gate trigger current while designing gating circuits to effectively control the operation of the GTO.

The gate trigger current of a GTO is higher than that of a normal SCR due to its multi-cathode structure. The magnitude of the gate current is approximately 30% of the anode current and flows for a short duration to turn off the thyristor. Once the GTO is turned on, no further gate current is required as the device maintains conduction. However, the higher gate trigger current in GTOs results in greater gate drive circuit losses compared to SCRs. To reliably turn on a GTO, the gate trigger current pulse must have sufficient amplitude and duration.

Click here to learn more about GTO thyristors listed on everything PE.