A Monolithic 48V-to-1V 10A Quadruple Step-Down DC-DC Converter with Hysteretic Copied On-Time 4-Phase Control and 2× Slew Rate All-Hysteretic Mode

Abstract

This paper presents a 48V-to-1V quadruple step-down (QSD) DC-DC converter. The QSD comprising 4 parallel-inductors and 3 series-capacitors can efficiently supply up to 10A with fully monolithic 12V LDMOS by lowering the switching voltage to be quartered. The hysteretic copied on-time (HCOT) control allows clockless synchronization of 4-phase QSD without collapsing series-capacitor voltages. The 2-phase all-hysteretic (2× slew rate) mode is also presented for voltage droop mitigation under extreme load fluctuations. The chip fabricated in 0.18-μm BCD shows a peak efficiency of 88.5% and achieves ∆80mV sag and 1μs 2%-recovery time for a 6.3A/50ns load transition.