Detection device, sensor, and electronic instrument
First Claim
1. 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 W1a and L1a, 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 W1b and L1b, and a bias current flowing through the differential section of the reference-voltage second-type operational amplifier is referred to as Ib, W1b×
L1b>
W1a×
L1a and Ia>
Ib being satisfied.
1 Assignment
0 Petitions
Accused Products
Abstract
A detection device includes a detection circuit and a reference voltage supply circuit. The detection circuit includes an amplifier circuit, a synchronous detection circuit, and a filter section. The reference voltage supply circuit includes a first supply circuit which includes a reference-voltage first-type operational amplifier and supplies an analog reference voltage to the amplifier circuit, and a second supply circuit which includes a reference-voltage second-type operational amplifier and supplies the analog reference voltage to the filter section. When a channel width and a channel length of a differential-stage transistor of a differential section of the first-type operational amplifier are respectively referred to as W1a and L1a, a bias current flowing through the differential section is referred to as Ia, a channel width and a channel length of a differential-stage transistor of a differential section of the second-type operational amplifier are respectively referred to as W1b and L1b, and a bias current flowing through the differential section is referred to as Ib, W1b×L1b>W1a×L1a and Ia>Ib are satisfied.
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Citations
20 Claims
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1. A detection device comprising:
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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 W1a and L1a, 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 W1b and L1b, and a bias current flowing through the differential section of the reference-voltage second-type operational amplifier is referred to as Ib, W1b×
L1b>
W1a×
L1a and Ia>
Ib being satisfied. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 16, 17, 19)
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13. A detection device comprising:
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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; the reference-voltage first-type operational amplifier being an operational amplifier of which thermal noise at a frequency of a carrier signal is lower than that of the reference-voltage second-type operational amplifier; and the reference-voltage second-type operational amplifier being an operational amplifier of which flicker noise at a frequency of a desired signal is lower than that of the reference-voltage first-type operational amplifier. - View Dependent Claims (14, 15, 18, 20)
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Specification