An Integrated Driver With Dual-Edge Adaptive Dead-Time Control for GaN-Based Synchronous Buck Converter

Abstract

This paper presents an integrated gate driver for a GaN-based synchronous buck converter with a novel dual-edge adaptive dead-time control (DTC) to minimize the dead-time and the reverse conduction loss on both transition edges of the switching node voltage. Two function blocks, phase error detector (PED) and coarse/fine controller, are created to detect the real dead-time and calibrate it to the sub-ns range, respectively. The control mechanism combines both analog and digital principles. The driver IC was fabricated by TSMC 0.18 ${\bm{\mu}}$ m HVG2 process with a die area of 1.5 $\mathrm{m}{{\mathrm{m}}^2}$ . Measurement results show that less than 1 ns dead-times are achieved in the entire load current range of 0.2 to 2 A for a 1 MHz 12-to-5V GaN-based buck converter. Thus, the measured peak efficiency reaches 94.15%.