A Two-Phase 2MHz DSD GaN Power Converter with Master-Slave AO2T Control for Direct 48V/1V DC-DC Conversion

This paper reports a GaN power converter that achieves direct 48V/1V DC-DC voltage conversion with a two-phase DSD architecture at 2MHz, pushing the minimum duty ratio to a record low level of 2.1%. The AO²T control with elastic ON-time modulator leads to significant improvement on transient response and voltage droop performance, compared to prior arts. A master phase mirror enables adaptive master-slave phase operation, accomplishing automatic phase current balancing for improved reliability. The converter achieves a peak efficiency of 85.4%, with an active die of 1.46mm² on 180nm HV BCD process.