Patent ID: 8710896

Claim:
A sampling switch circuit that uses correlated level shifting, the sampling switch circuit comprising: a sampling switch having a first terminal, a control terminal, and an output terminal, wherein the first terminal is connected to an input voltage node; a boosting circuit connected to first and second supply voltage nodes and coupled to the control terminal of the sampling switch; a correlated level shifting buffer circuit comprising: an amplifier having first and second inputs and an output, wherein the first input is connected to the input voltage node, and the output and second input are coupled to the boosting circuit; and a level shifting capacitor coupled to the second input and output of the amplifier, to the boosting circuit, and to a level shifting voltage node; wherein when an input voltage is connected to the input voltage node, a first supply voltage is connected to the first supply voltage node, and a second supply voltage is connected to the second supply voltage node, the sampling switch circuit is configured to generate, using only one estimate phase and one level shift phase, a sampling signal at the control terminal of the sampling switch, wherein the sampling signal comprises a portion that is equal to the input voltage plus a difference between the first and second supply voltages.