Patent ID: 8289198

Claim:
A high-voltage switched capacitor circuit comprising: a plurality of capacitors each having a first terminal; and a plurality of bit switching circuits each including: a high-voltage sampling switch circuit having a first terminal coupled to a second terminal of a corresponding capacitor and a second terminal coupled to receive a high-voltage analog input signal, and a third terminal coupled to an intermediate conductor; and a low-voltage conversion switch circuit including a first terminal coupled to the intermediate conductor, a second terminal coupled to receive a first reference voltage, and a third terminal coupled to receive a second reference voltage; a plurality of low-voltage combinational logic circuits for generating a plurality of low-voltage first signals, respectively, in response to a sampling level of a mode control signal, each low-voltage combinational logic circuit also generating low-voltage second and third signals according to a corresponding one of a plurality of bit signals, respectively, during a predetermined level of the mode control signal; and a plurality of level-shifting circuits each having an input coupled to receive a corresponding low-voltage first signal, each level-shifting circuit generating a corresponding high-voltage second signal to control coupling of the first terminal of a corresponding high-voltage sampling switch circuit to the high-voltage analog input signal during the sampling level and to the intermediate conductor during the pre-determined level.