A study on radiation effects on PWM-IC controller of DC/DC power buck converter

DC-DC converter is composed of a PWM-IC (pulse width modulation-integrated circuit) controller, a MOSFET (metal-oxide semiconductor field effect transistor), inductor, capacitor, etc. PWM is applied to control and regulate the total output voltage. It is shown that the variation of threshold voltage at MOSFET and the offset voltage increase caused by radiation effects make the PWM pulse unstable. Radiation gives the main influence on the changes in the electrical characteristics of PWM-IC and MOSFET. In the PWM operation, the missing pulses, the changes in pulse width, and a change of the output waveform are studied by the simulation program with integrated circuit emphasis (SPICE) and compared with experiments.