In this paper the characteristics of the single gate MOS controlled current saturation thyristor (MCST) is investigated in comparison with the MCT and IGBT. In the on-state the MCST operates in the thyristor-like mode at low anode voltage and enters the IGBT-like mode automatically with increasing anode voltage. It offers a low on-state voltage drop and current saturation capability. A simplified analytical model for the on-state is presented. The saturation current density of the MOST is strongly dependent on the ratio of the p(+) buffer doping to the n-well doping, i.e., alpha(pnp2)/alpha(npn), and drops with increasing temperature, leading to its excellent safe operating area and making it suitable for high power applications. (C) 2003 Elsevier Science Ltd. All rights reserved.