Patent ID: 7688121

Claim:
A power supply voltage detection circuit, comprising: a first switch to connect between a power supply voltage terminal and a first terminal according to a power supply voltage detection signal and an external signal; a second switch to connect between a reference potential terminal and a second terminal according to the power supply voltage detection signal and the external signal; a first resistance connected between said second terminal and the power supply voltage terminal; a third switch to connect between said first terminal and the reference potential terminal according to a voltage of said second terminal; and an output circuit to output said power supply voltage detection signal based on a signal from said first terminal; wherein said first switch includes fourth and fifth switches connected in parallel between the power supply voltage terminal and said first terminal; wherein said fourth switch connects between the power supply voltage terminal and said first terminal according to said power supply voltage detection signal; wherein said fifth switch connects between the power supply voltage terminal and said first terminal according to said external signal; wherein said second switch includes sixth and seventh switches connected in parallel between the reference potential terminal and said second terminal; wherein said sixth switch connects between the reference potential terminal and said second terminal according to said power supply voltage detection signal; and wherein said seventh switch connects between the referential potential terminal and said second terminal according to said external signal.