A Comparative Study of Switching Loss in IGBT and CoolMos Power Switch Devices

In high voltage and current applications, the power switch, IGBT has become more attractive due to its high voltage and current ratings than MOSFET. However, due to its slow turn-on and high turn-off losses it is unsuitable for high switching application. A newly developed device, CoolMos, using improved MOSFET feature, with lower RDS(ON) is introduced. Whilst turn-off switching loss is determined to be constant, the turn-on switching losses in these two power switches is found to be 78.5 % better in CoolMos. A conventional buck converter using IGBT (IRG4BC20W 6.5 A/600 V) and CoolMos (SPP07N60C3 7.3 A/650 V) were investigated to show that the total switching loss in the circuit could be significantly improved using CoolMos as the switch. A 40 kHz, 1.5 Watts prototype converter has been constructed to verify the simulated analysis. It can be seen that using CoolMos as the switching device, the total switching loss indicates an improvement of 68%