Patent ID: 8598939
Filing Date: 2013-12-03
Classification: G01S,H03K

Abstract:
1. A switch circuit, comprising: a main switch having a first MOS transistor, to a drain terminal of which a first input/output terminal is connected, and a second MOS transistor, to a drain terminal of which a second input/output terminal is connected, wherein a source terminal of the first MOS transistor and a source terminal of the second MOS transistor are connected forming a common source terminal and wherein a gate terminal of the first MOS transistor and a gate terminal of the second MOS transistor are connected forming a common gate terminal; a voltage control circuit which is connected to the common source terminal and the common gate terminal of the main switch, which makes potential of the common gate terminal follow, in phase, variation in common source potential that is a potential of the common source terminal, and which controls, using a gate control signal, turning on or off of the main switch; wherein the voltage control circuit includes: a first latch circuit which is connected to a first power supply terminal and the common source terminal and which level-shifts a control signal inputted from a logic input terminal to form a control signal based on the common source potential; a voltage generator which is connected to the common source terminal and which generates a certain level of internal voltage based on the common source potential; and a second latch circuit which is connected to the common source terminal, to which the internal voltage is inputted as power supply, and which sends, based on the control signal, the gate control signal to the common gate terminal.