A low-power automatic supply multiplexer for reconfigurable step-up/down switching DC-DC converters

This paper presents a low-power automatic supply multiplexer for reconfigurable step-up/down switching DC-DC converters. The multiplexer continuously compares the input and the output voltages. It then tracks and selects the higher voltage to be used for substrate biasing and supplying gate drivers. This reduces leakage current through substrate diodes and also reduces conduction losses of the driven power transistors. The proposed multiplexer consumes 7.13 micro Watts at 2.5-V input and achieves zero tracking error at steady state and has a tracking speed of 5.83 mV/ns.