Patent ID: 7870786

Claim:
A detection device comprising: a detection circuit that receives a detection signal from a physical quantity transducer driven using a driving signal, and detects a desired signal from the detection signal; and a reference voltage supply circuit that supplies an analog reference voltage to the detection circuit; the detection circuit including: an amplifier circuit that amplifies the detection signal from the physical quantity transducer; a synchronous detection circuit that synchronously detects a signal amplified by the amplifier circuit; and a filter section provided in a subsequent stage of the synchronous detection circuit; the reference voltage supply circuit including: a first supply circuit that includes a reference-voltage first-type operational amplifier and supplies the analog reference voltage to the amplifier circuit; and a second supply circuit that includes a reference-voltage second-type operational amplifier and supplies the analog reference voltage to the filter section; and when a channel width and a channel length of a differential-stage transistor of a differential section of the reference-voltage first-type operational amplifier are respectively referred to as W 1 a and L 1 a , a bias current flowing through the differential section of the reference-voltage first-type operational amplifier is referred to as Ia, a channel width and a channel length of a differential-stage transistor of a differential section of the reference-voltage second-type operational amplifier are respectively referred to as W 1 b and L 1 b , and a bias current flowing through the differential section of the reference-voltage second-type operational amplifier is referred to as Ib, W 1 b ×L 1 b >W 1 a ×L 1 a and Ia>Ib being satisfied.