Abstract
Failure of a power MOSFET in the avalanche mode results from forward biasing the base emitter junction of the parasitic NPN transistor, turning it on . Once the MOSFET structure has been optimized the avalanche rating becomes a matter of guaranteeing high current avalanche operation at maximum operating junction temperature . This is done using the signle pulse avalanche energy( )test/rating by micro-controller . The test is designed to test the device at full rated operating junction temperature and high current density . An example of how to calculate the transient thermal impedance from junction temperature and breakdown voltage is presented . In addition, the PWM(Pulse Width Modulation) with over-current protection circuit in a signle chip are discussed .