High-efficiency voltage booster circuit operating at very low supply

Abstract

A voltage booster circuit including a pull-up capacitor connected to the supply line via a PMOS switching transistor. The other terminal of the pull-up capacitor is supplied with a pull-up voltage switching between a first value determining charging of the capacitor, and a second value higher than the first and determining pull-up of the capacitor. A negative voltage source presents an output connected to the control terminal of a switch transistor, and generates a negative voltage of a value lower than the first pull-up voltage value when charging the capacitor, so as to saturate the switch transistor and charge the capacitor to a voltage close to the supply voltage.