Analysis of parallel coolmos under saturation-mode operation

In this paper we study the parallel operation of power MOSFETs. Normally, being switches, they operate either in the cut-off region or in the linear region, thus acting as a switch. However, in some fault conditions it is necessary for the MOSFET to be used to limit the current, in which case the device may operate in the saturation region. The MOSFET can only operate in this region for a finite amount of time, as is limited by thermal considerations. Specifically in this paper we study the parallel operation of CoolMOS devices using stat-of-the-art electrothermal models implemented in SABER. The simulation results reported in this paper offer a valuable insight into the parallel operation of super junction MOSFETs operating in the saturationmode operation. By varying the properties of one of the MOSFETs in parallel, the effect on system thermal stability is explored and hence is used to enhance the reliability of such paralleled devices.