Patent ID: 7385440
Filing Date: 2008-06-10
Classification: H03K,H03M

Abstract:
1. A bootstrapping circuit capable of sampling inputs beyond supply voltage comprising: a bootstrapped switch coupled between an input node and an output node; a first transistor having a first end coupled to a control node of the bootstrapped switch, and having a backgate coupled to a second end of the first transistor; a first capacitor having a first end coupled to the second end of the first transistor; a second transistor coupled between the first end of the first transistor and a supply node, and having a control node coupled to a first clock signal node; a third transistor coupled between the second end of the first transistor and the supply node; a charge pump having an output coupled to a control node of the third transistor; a level shifter having a first output coupled to a second end of the first capacitor; a fourth transistor coupled between the supply node and a control node of the first transistor; and a fifth transistor coupled between the output of the charge pump and a control node of the fourth transistor, and having a control node coupled to the supply node, and having a backgate coupled to the output of the charge pump.