Temperature effects on the conducted emission of a high-side switch

Abstract

Current source MOSFET gate drive circuits are used in many electronic equipment. These drivers allow supplying an optimized current profile to charge and discharge the gate of a power MOSFET. The reason, among others, to use such drivers is to generate a “trapezoidal output signal” with round corner in order to reduce the electromagnetic emissions characteristic of the equipment, especially in high frequency range. The current profile is usually determined by simulation, adjusted by measurement and finally fixed for the equipment which means that it cannot be changed once the equipment is used in its application. At the same time, during its life, the equipment, will experience environmental parameter variations such as temperature. This paper presents a study highlighting the effects of temperature on the conducted emission characteristics of high-side switch circuit embedding the driver circuit and the power transistor. This study has been done on a given circuit and should be enlarged on others to generalize the conclusions.