Patent ID: 6965263

Claim:
A charge pump for converting an input voltage to an output voltage of a different magnitude or polarity, comprising: a voltage booster for coupling to the input voltage for switching stored charge to a boosted voltage output, the voltage booster configured to generate a boosted voltage as a fluctuating voltage potential above and below the output voltage, the boosted voltage output having a boosted voltage thereon of a different magnitude or polarity from the input voltage; a pass gate for providing isolation and transfer between the boosted voltage and the output voltage, the pass gate coupled at an input terminal of the pass gate to the boosted voltage output of the voltage booster, the potential between the boosted voltage and the output voltage alternating during each of the switching of stored charge by the voltage booster, the pass gate further including an output terminal, a gate terminal, and a bulk node; and a biasing circuit for selecting a bulk node biasing voltage for the pass gate from among the boosted voltage and the output voltage, including: a first switch having a first switch terminal for coupling to the boosted voltage and a second switch terminal for coupling to the bulk node of the pass gate, the first switch further including a control terminal for coupling to the output voltage, the control terminal responsive to an applied voltage to enable conduction between the first switch terminal and the second switch terminal of the first switch; and a second switch having a first switch terminal for coupling to the bulk node of the pass gate and a second switch terminal for coupling to the output voltage, the second switch further including a control terminal for coupling to the boosted voltage, the control terminal responsive to an applied voltage to enable conduction between the first switch terminal and the second switch terminal of the second switch.