Low-temperature operation of a Buck DC/DC converter

Low-temperature (77 K) operation of a 42/28 V, 175 W, 50 kHz PWM buck DC/DC power converter designed with commercially available components is reported. Overall, the power converter losses decreased at 77 K compared to room temperature operation. A full-load efficiency of 97% was recorded at liquid-nitrogen temperature, compared to 95.8% at room temperature. Power MOSFET operation improved significantly whereas the output rectifier operation deteriorated at low-temperature. The performance of the output filter inductor and capacitor did not change significantly at 77 K compared to room temperature performance. It is possible to achieve high-density and high efficiency power conversion at low-temperatures due to improved electronic, electrical and thermal properties of materials. >