Sense Device Structure in Hybrid IGBT with Constant Current Sense Ratio for Entire Collector Current Range

Abstract

A new sense device structure is proposed for hybrid IGBTs in which current sensing ratio (CSR) is constant for a wide range of collector currents (I CE ). Hybrid IGBTs are a new type of switching device, with 2 operation modes: MOS operation mode at low I CE and IGBT operation mode at high I CE . Although the current flow mechanism is different between the two modes, it is preferable that CSR in both MOS IGBT operation modes be the same. It is also important to reduce the difference in CSR when the hybrid IGBT changes from MOS to IGBT operation mode.The new sense structure allows maintaining a constant CSR for the entire range of I CE . Moreover, CSR has low temperature dependence when the new sense device is adopted. As a result, I CE can be controlled more stably over a wide temperature range (-50 o C -125 o C) even for hybrid IGBTs