An Adaptive Zero-Current Detector for Single-Inductor Multiple-Output DC-DC Converter With Full-Wave Current Sensor

This brief presents an adaptive zero-current detector (ZCD) for the single-inductor multiple-output (SIMO) DC-DC converter with a full-wave current sensor. The innovative adaptive ZCD, which can be applied to the order power distribution control (OPDC) SIMO DC-DC converter, is designed, and it can accurately turn off the low-side power switch when the SIMO DC-DC converter operates in the discontinuous conduction mode. Besides, a new full-wave current sensor which contains only one sensing transistor is presented, and it can precisely sense the inductor current with a small delay. The SIMO DC-DC converter is designed and fabricated in a standard 65 nm CMOS process with output power ranges from 3.7 to 925 mW. The measured reverse current is reduced by up to 78.2%, and the measured light-load power efficiency is improved by up to 10%.