GaN FET-based synchronous buck converter with 10-bit 4-MHz digital pulse width modulator

Architecture of the gallium nitride (GaN) FET-based synchronous buck converter with 10-bit, 4-MHz digital pulse width modulator (DPWM) is presented. The DPWM integrated in proposed architecture has a high resolution and a high operating frequency. In addition, the proposed architecture can control its duty-cycle and dead-time of PWM outputs detail by this DPWM. The testing board, which is manufactured by discrete devices and a custom IC, demonstrates 26.9-W with 91.3% efficiency of the power stage at 4-MHz switching frequency. Experimental results also show the wide duty-range operation controlled by the DPWM.