Circuit device, physical quantity detection device, electronic apparatus, and moving object

Patent metadata

Field	Value
Publication number	US-2016274181-A1
Application number	US-201615067350-A
Country	US
Kind code	A1
Filing date	Mar 11, 2016
Priority date	Mar 16, 2015
Publication date	Sep 22, 2016
Grant date	—

Abstract

A circuit device includes a detection circuit to which first and second detection signals forming differential signals are input from a physical quantity transducer and a diagnosis circuit. The detection circuit includes first and second charge/voltage conversion circuits. The diagnosis circuit includes a first capacitor which is provided between a first node and a first input node to which the first detection signal is input and a second capacitor which is provided between the first node and a second input node to which the second detection signal is input and has a different capacitor value from the first capacitor. In a diagnosis mode, a diagnosis signal is input to the first node.

First claim

What is claimed is:

1 . A circuit device comprising:
a detection circuit to which first and second detection signals forming differential signals are input from a physical quantity transducer; and a diagnosis circuit of the detection circuit, wherein the detection circuit includes
a first charge/voltage conversion circuit to which the first detection signal is input, and
a second charge/voltage conversion circuit to which the second detection signal is input, and
wherein the diagnosis circuit includes
a first capacitor which is provided between a first node and a first input node of the first charge/voltage conversion circuit to which the first detection signal is input, and
a second capacitor which is provided between the first node and a second input node of the second charge/voltage conversion circuit to which the second detection signal is input and has a different capacitor value from the first capacitor, and
wherein in a diagnosis mode, a diagnosis signal is input to the first node.

2 . The circuit device according to claim 1 , further comprising:
a first terminal to which the first detection signal is input; and a second terminal to which the second detection signal is input, wherein the diagnosis circuit includes
a first switch element which is provided between one end of the first capacitor and the first input node,
a second switch element which is provided between one end of the second capacitor and the second input node,
a third switch element which is provided between the first terminal and the first input node, and
a fourth switch element which is provided between the second terminal and the second input node.

3 . The circuit device according to claim 2 ,
wherein in the diagnosis mode, the first and second switch elements are turned on and the third and fourth switch elements are turned off.

4 . The circuit device according to claim 3 ,
wherein during a normal operation period in which the detection circuit performs a detection operation, the first and second switch elements are turned off and the third and fourth switch elements are turned on.

5 . The circuit device according to claim 2 ,
wherein after supply of power and before a normal operation period in which the detection circuit performs a detection operation, the first and second switch elements are turned on.

6 . The circuit device according to claim 3 ,
wherein after supply of power and before a normal operation period in which the detection circuit performs a detection operation, the first and second switch elements are turned on.

7 . The circuit device according to claim 4 ,
wherein after supply of power and before the normal operation period in which the detection circuit performs the detection operation, the first and second switch elements are turned on.

8 . The circuit device according to claim 1 , further comprising:
a control unit that performs control such that switch elements are turned on or off, wherein the diagnosis circuit includes
a first switch element which is provided between one end of the first capacitor and the first input node, and
a second switch element which is provided between one end of the second capacitor and the second input node, and
wherein after supply of power and before a normal operation period in which the detection circuit performs a detection operation, the control unit turns on the first and second switch elements.

9 . The circuit device according to claim 1 , further comprising:
a driving circuit which drives the physical quantity transducer, wherein a signal based on a signal from the driving circuit is input as the diagnosis signal to the first node.

10 . The circuit device according to claim 2 , further comprising:
a driving circuit which drives the physical quantity transducer, wherein a signal based on a signal from the driving circuit is input as the diagnosis signal to the first node.

11 . The circuit device according to claim 3 , further comprising:
a driving circuit which drives the physical quantity transducer, wherein a signal based on a signal from the driving circuit is input as the diagnosis signal to the first node.

12 . The circuit device according to claim 4 , further comprising:
a driving circuit which drives the physical quantity transducer, wherein a signal based on a signal from the driving circuit is input as the diagnosis signal to the first node.

13 . The circuit device according to claim 9 ,
wherein a signal obtained by converting a voltage level of the signal from the driving circuit is input as the diagnosis signal to the first node.

14 . The circuit device according to claim 9 ,
wherein the detection circuit includes a synchronization detection circuit which performs synchronization detection based on a synchronization signal from the driving circuit, and wherein the diagnosis signal is a signal having the same phase as the synchronization signal.

15 . The circuit device according to claim 9 ,
wherein the detection circuit includes a differential amplification circuit which is provided on a rear side of the first and second charge/voltage conversion circuits and performs differential amplification on signals output from the first and second charge/voltage conversion circuits.

16 . The circuit device according to claim 1 ,
wherein a detection result in the detection circuit in the diagnosis mode is output.

17 . The circuit device according to claim 16 , further comprising:
a register unit which outputs the detection result, wherein the detection circuit includes an A/D conversion circuit which performs A/D conversion on a detection result signal in the detection circuit, and wherein in the register unit, diagnosis result data obtained by performing the A/D conversion on the detection result signal in the diagnosis mode is set as the detection result.

18 . A physical quantity detection device comprising:
the circuit device according to claim 1 ; and a physical quantity transducer.

19 . An electronic apparatus comprising:
the circuit device according to claim 1 .

20 . A moving object comprising:
the circuit device according to claim 1 .

Assignees

• Seiko Epson Corp

Inventors

• Aoyama Takashi

Classifications

• G01R31/2829 Primary

  Testing of circuits in sensor or actuator systems (testing of apparatus for measuring electric or magnetic variables G01R35/00; testing of indicating or recording apparatus G01D; in airbag systems B60R21/0173; checking gas analysers G01N33/007; monitoring or fail-safe circuits for electromagnets H01F7/1844) · CPC title

• G01C19/5776

  Signal processing not specific to any of the devices covered by groups G01C19/5607 - G01C19/5719 · CPC title

• G01C19/5649 Primary

  Signal processing · CPC title

• H03F3/45475

  using IC blocks as the active amplifying circuit · CPC title

• G01D3/08

  with provision for safeguarding the apparatus, e.g. against abnormal operation, against breakdown · CPC title