To provide a power supply switching device having an N-channel MOSFET used as a switch element which power supply switching device prevents backflow and avoids a rise in the threshold voltage to the switch element caused by substrate bias effect.
The power supply switching device includes an N-channel switch MOS transistor (Q1), connected between a voltage input terminal and an output terminal. The power supply switching device also includes a first MOS transistor (M2), connected between the base of the switch MOS transistor and a ground point, and a second MOS transistor (M1), connected between the base of the switch MOS transistor and a point of a prescribed constant potential higher than a potential at the ground point. While the switch MOS transistor (Q1) is turned on, the prescribed constant potential higher than the potential at the ground point is applied to the base of the switch MOS transistor; and while the switch MOS transistor (Q1) is turned off, the ground potential is applied to the base of the switch MOS transistor.
KAWAGOE OSAMU
NAGAI TOMIYUKI
TABUCHI HITOYUKI
| JPH04162111A | 1992-06-05 | |||
| JPH03243119A | 1991-10-30 | |||
| JP2003347913A | 2003-12-05 |
Yoshio Arafune