Detection device, sensor, electronic apparatus, and moving object

Patent metadata

Field	Value
Publication number	US-9698686-B2
Application number	US-201414533483-A
Country	US
Kind code	B2
Filing date	Nov 5, 2014
Priority date	Nov 7, 2013
Publication date	Jul 4, 2017
Grant date	Jul 4, 2017

Abstract

A detection device includes a driving circuit which drives a physical quantity transducer, a detection circuit which detects a desired signal, a power-supply terminal into which a power-supply voltage is input, a regulator circuit which performs a voltage adjustment of stepping down the power-supply voltage from the power-supply terminal, and supplies a regulated power-supply voltage obtained by the voltage adjustment to the driving circuit and the detection circuit as an operating power-supply voltage, and a buffer circuit which is supplied with the power-supply voltage, receives a drive signal from the driving circuit, and outputs an amplified drive signal in which an amplitude of the drive signal increases to the physical quantity transducer.

First claim

What is claimed is:

1. A detection device, comprising:
a driving circuit which receives a feedback signal from a physical quantity transducer, and drives the physical quantity transducer, and wherein the driving circuit amplifies a signal based on the feedback signal and outputs the amplified signal, as a drive signal;
a detection circuit which receives a detection signal from the physical quantity transducer, and detects a desired signal;
a power-supply terminal into which a power-supply voltage is input;
a regulator circuit which performs a voltage adjustment of stepping down the power-supply voltage from the power-supply terminal, and supplies a regulated power-supply voltage obtained by the voltage adjustment to the driving circuit and the detection circuit as an operating power-supply voltage; and
a buffer circuit receives the power-supply voltage, and receives the drive signal from the driving circuit, wherein the buffer circuit is operable to output an amplified drive signal in which an amplitude of the drive signal increases to the physical quantity transducer.

2. The detection device according to claim 1 ,
wherein the amplified drive signal from the buffer circuit is output to the physical quantity transducer in a first mode, and
the drive signal from the driving circuit is output to the physical quantity transducer in a second mode.

3. The detection device according to claim 2 ,
wherein the physical quantity transducer is a vibrator, and
the detection device is set to the first mode in a start-up period of oscillation of the vibrator, and the amplified drive signal from the buffer circuit is output to the vibrator.

4. The detection device according to claim 3 ,
wherein the detection device is set to the second mode after the start-up period is completed, and the drive signal from the driving circuit is output to the vibrator.

5. A sensor, comprising:
the detection device according to claim 2 ; and
the physical quantity transducer.

6. A sensor, comprising:
the detection device according to claim 3 ; and
the physical quantity transducer.

7. An electronic apparatus comprising the detection device according to claim 2 .

8. The detection device according to claim 1 ,
wherein the buffer circuit includes
an operational amplifier in which the drive signal from the driving circuit is input into a non-inversion input terminal, and
a first resistive element and a second resistive element which are disposed between an output node of the operational amplifier and a node of a low potential side electric power supply in series, and
a connection node between the first resistive element and the second resistive element is connected to an inversion input terminal of the operational amplifier.

9. The detection device according to claim 1 ,
wherein the driving circuit and the detection circuit are configured by a transistor of a first pressure resistance, and
the buffer circuit is configured by a transistor of a second pressure resistance which is a pressure resistance higher than the first pressure resistance.

10. The detection device according to claim 1 ,
wherein the physical quantity transducer is a vibrator,
the driving circuit includes
a current-voltage conversion circuit which receives the feedback signal, and performs a current-voltage conversion,
a drive signal output circuit which amplifies an input voltage signal after being subjected to the current-voltage conversion by the current-voltage conversion circuit, and outputs the drive signal of a sine wave, and
a gain control circuit which controls a gain of amplification of the drive signal in the drive signal output circuit, and
when a resistance for a current-voltage conversion of the current-voltage conversion circuit is set to RI, the gain of the amplification of the drive signal by the drive signal output circuit and the buffer circuit is set to K, and an equivalent series resistance in a fundamental wave mode of the vibrator is set to R, the gain control circuit performs a gain control such that K×RI=R is satisfied.

11. The detection device according to claim 10 ,
wherein the drive signal output circuit includes
an Operational Transconductance Amplifier (OTA) circuit in which a transconductance is set by a control voltage from the gain control circuit, and the input voltage signal is converted into a current signal, and
a second current-voltage conversion circuit which performs a current-voltage conversion with respect to the current signal from the OTA circuit, and outputs the drive signal.

12. The detection device according to claim 11 ,
wherein the OTA circuit includes
a voltage-current conversion circuit which converts the control voltage from the gain control circuit into a control current, and
a differential unit in which a bias current set by the control current flows to a bias current source, an analog based voltage is input into a first differential input terminal, an input voltage signal is input into a second differential input terminal, and the current signal is output to the second current-voltage conversion circuit.

13. The detection device according to claim 1 , further comprising:
a second driving circuit which receives a second feedback signal from a second physical quantity transducer, and drives the second physical quantity transducer;
a second detection circuit which receives a second detection signal from the second physical quantity transducer, and detects a desired signal;
a second regulator circuit which performs a voltage adjustment of stepping down the power-supply voltage from the power-supply terminal, and supplies a second regulated power-supply voltage obtained by the voltage adjustment to the second driving circuit and the second detection circuit; and
a second buffer circuit which is supplied with the power-supply voltage, receives a second drive signal from the second driving circuit, and outputs a second amplified drive signal in which an amplitude of the second drive signal increases to the second physical quantity transducer.

14. The detection device according to claim 13 ,
wherein the amplified drive signal from the buffer circuit is output to the physical quantity transducer, and the second amplified drive signal from the second buffer circuit is output to the second physical quantity transducer in a first mode, and
the drive signal from the driving circuit is output to the physical quantity transducer, and the second drive signal from the second driving circuit is output to the second physical quantity transducer in a second mode.

15. The detection device according to claim 13 ,
wherein the physical quantity transducer is a vibrator for detecting a rotation angular velocity around a first axis, and
the second physical quantity transducer is a vibrator for detecting a rotation angular velocity around a second axis.

16. A sensor, comprising:
the detection device according to claim 1 ; and
the physical quantity transducer.

17. An electronic apparatus comprising the detection device according to claim 1 .

18. A moving object comprising the detection device according to claim 1 .

19. A detection device, comprising:
a driving circuit that receives a feedback signal from a physical quantity transducer, wherein the driving circuit amplifies a signal based on the feedback signal and outputs the amplified signal as a drive signal;
a detection circuit that receives a detection signal from the physical quantity transducer, and detects a desired signal;
a power-supply terminal into

Assignees

• Seiko Epson Corp

Inventors

• Maki Katsuhiko
• Higuchi Teppei
• Nomiya Takashi

Classifications

• H03G3/3005

  in amplifiers suitable for low-frequencies, e.g. audio amplifiers (H03G3/32, H03G3/34 take precedence) · CPC title

• H03F2203/45528

  the FBC comprising one or more passive resistors and being coupled between the LC and the IC · CPC title

• H03F2200/261

  Amplifier which being suitable for instrumentation applications · CPC title

• H03F2203/45674

  the LC comprising one current mirror · CPC title

• H03F3/45475

  using IC blocks as the active amplifying circuit · CPC title