The 5SGA40L4501 from ABB is an Asymmetrical Gate Turn-Off Thyristor that has been designed to withstand effects due to cosmic radiation. It has a break-over voltage of up to 4500 V and a break-over current of less than 4000 A. This thyristor has a gate trigger voltage of 1.2 V and a gate trigger current of 4 A. It is based on patented free-floating silicon technology with an annular gate electrode construction. This asymmetric GTO offers low on-state and switching losses for power-efficient applications. It is available in a disc package that measures 120 x 26 mm.