Agilent 5992-0207EN Precise Evaluation of Input 252COutput 252C and Reverse Transfer Capacitances of Power D free download

File name 5992-0207EN Precise Evaluation of Input_252COutput_252C and Reverse Transfer Capacitances of Power D

Keysight Technologies Precise Evaluation of Input, Output, and Reverse Transfer Capacitances of Power Devices White Paper 2 | Keysight | Precise Evaluation of Input, Output, and Reverse Transfer Capacitances of Power Devices - White Paper Increasing Importance of Capacitance Measurement The switching frequency in power conversion circuits is increasing. This is primarily to reduce the size of passive components such as smoothing capacitors and reactors. Accurate char- acterization of device parameters affecting switching performance become more important as higher switching frequencies increase power circuit switching losses. Let's use the power MOSFET shown in Figure 1 as an example. Gate resistance (Rg), input, output and reverse transfer capacitances (Ciss, Coss and Crss) are described in a device datasheet as typical parameters related to switching performance. Figure 1. Three Capacitances of Power MOS FET Rg and Crss dictate switching speed while Ciss determines driving condition. Power loss due to charging and discharging Coss is the primary component of switching loss in the case of a resonant converter. Crss and Coss have voltage dependency in the nano-farad range due to the power device's depletion region modulating with applied varying operational voltages. These capacitances are conventionally measured by LCR meter. However, the maximum volt- age of an integrated LCR voltage source is limited to around