Time Variable Dead-Time in GaN Based Bridgeless Converter

Power factor correction (PFC) bridgeless converter in Fig. 1 with GaN transistors achieves better efficiency and power density compared to other solutions in the field of PFC converters. Utilizing GaN transistors brings new challenges in the field of control algorithms. Mainly the high frequency operation demanding high resolution PWM generator timers and precise dead-time setting together with fast control loop calculations and feedback values measurements. This paper presents a software based solution to on-line deadtime adjustment which improves the efficiency of GaN based PFC converters.