Discussion of Internal Noise Currents in a Control Circuit on a 200-kHz Switching PWM Inverter

This paper discusses noise currents in a control or gate-drive circuit of a 200-kHz PWM inverter. When the MOSFETs of the inverter are turned-on or -off, the noise current flows into the control and drive circuits. As a result, a malfunction in the controller of the inverter may occur. The equivalent circuit for the noise current is estimated from the experimental waveforms. This paper discusses three suppression methods of the internal noise current, and experimental results verify the effectiveness of the proposed method. Finally, a design procedure for the gate-drive circuit of a high-frequency switching PWM inverter is described.