Patent ID: 7157813
Filing Date: 2007-01-02
Classification: H03K

Abstract:
1. An power supply control integrated circuit, comprising: a plurality of terminals including first, second and third terminals of the power supply control integrated circuit, wherein the first terminal is adapted to withstand a first maximum voltage relative to the second terminal, wherein the third terminal is adapted to withstand a second maximum voltage relative to the second terminal, wherein the second maximum voltage is substantially greater than the first maximum voltage; a power switch coupled between the third terminal and the second terminal, the power switch to switch high voltage at the third terminal in normal operation of the integrated circuit to control a power supply; a high voltage buffer circuit coupled to the third terminal; a voltage regulator circuit coupled to the high voltage buffer circuit; a functional circuit coupled to the voltage regulator circuit, to the first terminal and to the power switch; a detector circuit coupled to the high voltage buffer circuit to detect a voltage at the third terminal, the detector circuit having a first state when the voltage at the third terminal is less than a first threshold, the detector having a second state when the voltage on the third terminal is greater than a second threshold; and a selector circuit coupled to the detector circuit and the functional circuit, the selector circuit to select one of at least two distinct modes of operation for the functional circuit in response to a voltage at the third terminal.