Bootstrapping circuit capable of sampling inputs beyond supply voltage

Abstract

The bootstrapping circuit capable of sampling inputs beyond supply voltage includes: a bootstrapped switch MNcoupled between an input node and an output node; a first transistor MPhaving a first end coupled to a control node of the bootstrapped switch MNa clock bootstrapped capacitor Chaving a first end coupled to a second end of the first transistor MPa second transistor MNcoupled between the first end of the first transistor MPand a supply node, and having a control node coupled to a first clock signal node PHI; a third transistor MNcoupled between the second end of the first transistor MPand the supply node; a charge pump having a first output coupled to a control node of the third transistor MNa level shifter having a first output coupled to a second end of the clock bootstrapped capacitor Ca fourth transistor MNcoupled between the supply node and a control node of the first transistor MPand having a control node coupled to a second output of the charge pump; a capacitor coupled between a second output of the level shifter and a control node of the first transistor; and a fifth transistor MNcoupled between the control node of the bootstrapped switch MNand a common node.