Patent ID: 6348831
Filing Date: 2002-02-19
Classification: H03K

Abstract:
A semiconductor device comprising an analog switch and digital circuitry, both being formed on a single integrated circuit chip and sharing a node coupled to external circuitry comprising:a first power source coupled to an input terminal of said analog switch whose output is operatively coupled to said node; a second power source for supplying electric power to said digital circuitry whose input or output is operatively coupled to said node; and a back gate voltage controller, coupled to a back gate of said analog switch for controlling a voltage applied to said back gate in response to an operation mode control signal which represents whether said analog switch or said digital circuitry is to be enabled, said operation mode control signal coupled to said digital circuitry for enabling/disabling said digital circuitry while disabling/enabling said analog switch; and said back gate voltage controller is operative to clamp the voltage of said back gate to said first power source while said analog switch is in use, and to isolate said back gate from the first power source when said analog switch is not in use.