Circuit device, physical-quantity detecting apparatus, electronic apparatus, and moving object

Patent metadata

Field	Value
Publication number	US-2016276990-A1
Application number	US-201615068763-A
Country	US
Kind code	A1
Filing date	Mar 14, 2016
Priority date	Mar 16, 2015
Publication date	Sep 22, 2016
Grant date	—

Abstract

A circuit device includes a differential input-to-single-ended output first amplifier, to an inversion input terminal of which, of first and second signals forming differential signals, the first signal is input and to a non-inversion input terminal of which the second signal is input, a differential input-to-single-ended output second amplifier, to a non-inversion input terminal of which the first signal is input and to an inversion input terminal of which the second signal is input, and a failure detection circuit that performs failure detection on the basis of an output signal of the first amplifier and an output signal of the second amplifier.

First claim

What is claimed is:

1 . A circuit device comprising:
a differential input-to-single-ended output first amplifier, to an inversion input terminal of which, of first and second signals forming differential signals, the first signal is input and to a non-inversion input terminal of which the second signal is input; a differential input-to-single-ended output second amplifier, to a non-inversion input terminal of which the first signal is input and to an inversion input terminal of which the second signal is input; and a failure detection circuit that performs failure detection on the basis of an output signal of the first amplifier and an output signal of the second amplifier.

2 . The circuit device according to claim 1 , wherein the first and second amplifiers are amplifiers that perform a single-end output based on a same analog common voltage.

3 . The circuit device according to claim 2 , wherein the failure detection circuit performs the failure detection by detecting whether a monitoring voltage based on a voltage of the output signal of the first amplifier and a voltage of the output signal of the second amplifier is within a determination voltage range based on the analog common voltage.

4 . The circuit device according to claim 1 , wherein the failure detection circuit performs the failure detection on the basis of a monitoring voltage obtained by dividing a voltage of the output signal of the first amplifier and a voltage of the output signal of the second amplifier.

5 . The circuit device according to claim 4 , wherein the failure detection circuit performs the failure detection by detecting whether the monitoring voltage is within a determination voltage range between a threshold voltage on a high potential side and a threshold voltage on a low potential side.

6 . The circuit device according to claim 1 , wherein
the first amplifier includes: a first operational amplifier; a first resistance element provided between the inversion input terminal of the first amplifier and an inversion input terminal of the first operational amplifier; a second resistance element provided between the inversion input terminal of the first operational amplifier and an output terminal of the first operational amplifier; a third resistance element provided between the non-inversion input terminal of the first amplifier and a non-inversion input terminal of the first operational amplifier; and a fourth resistance element provided between the non-inversion input terminal of the first operational amplifier and an analog common voltage node, and the second amplifier includes: a second operational amplifier; a fifth resistance element provided between the inversion input terminal of the second amplifier and an inversion input terminal of the second operational amplifier; a sixth resistance element provided between the inversion input terminal of the second operational amplifier and an output terminal of the second operational amplifier; a seventh resistance element provided between the non-inversion input terminal of the second amplifier and a non-inversion input terminal of the second operational amplifier; and an eighth resistance element provided between the non-inversion input terminal of the second operational amplifier and the analog common voltage node.

7 . The circuit device according to claim 1 , further comprising:
a driving circuit configured to drive a physical quantity transducer; and a detection circuit to which first and second detection signals from the physical quantity transducer are input, wherein the detection circuit includes a differential amplifier circuit configured by the first and second amplifiers and configured to receive an input of the first and second signals corresponding to the first and second detection signals.

8 . The circuit device according to claim 7 , wherein the detection circuit includes:
a first charge/voltage conversion circuit provided on a pre-stage side of the differential amplifier circuit and configured to receive an input of the first detection signal and output the first signal; and a second charge/voltage conversion circuit provided on the pre-stage side of the differential amplifier circuit and configured to receive an input of the second detection signal and output the second signal.

9 . A circuit device comprising:
a first operational amplifier, to a non-inversion input terminal of which, of first and second signals forming differential signals, the first signal is input; a second operational amplifier, to a non-inversion input terminal of which the second signal of the first and second signals is input; a first voltage division circuit configured to divide a voltage at a first node and a voltage at an output terminal of the first operational amplifier and set an inversion input terminal of the first operational amplifier to a voltage obtained by the voltage division; a second voltage division circuit configured to divide the voltage at the first node and a voltage at an output terminal of the second operational amplifier and set an inversion input terminal of the second operational amplifier to a voltage obtained by the voltage division; and a failure detection circuit configured to perform failure detection on the basis of a monitoring voltage, which is the voltage at the first node.

10 . The circuit device according to claim 9 , wherein the first voltage division circuit includes:
a first resistance element provided between the first node and the inversion input terminal of the first operational amplifier; and a second resistance element provided between the inversion input terminal of the first operational amplifier and the output terminal of the first operational amplifier, and the second voltage division circuit includes: a third resistance element provided between the first node and the inversion input terminal of the second operational amplifier; and a fourth resistance element provided between the inversion input terminal of the second operational amplifier and the output terminal of the second operational amplifier.

11 . The circuit device according to claim 10 , wherein at least one of the first and second resistance elements and at least one of the third and fourth resistance elements are resistance elements having variable resistance values.

12 . The circuit device according to claim 9 , wherein
the first signal is a signal that changes to a positive side or a negative side on the basis of an analog common voltage, the second signal is a signal that changes to the positive side or the negative side on the basis of the analog common voltage, and the failure detection circuit performs failure detection by detecting whether the monitoring voltage is within a determination voltage range based on the analog common voltage.

13 . The circuit device according to claim 12 , wherein the failure detection circuit performs failure detection by detecting whether the monitoring voltage is within the determination voltage range between a threshold voltage on a high potential side and a threshold voltage on a low potential side.

14 . The circuit device according to claim 9 , further comprising:
a driving circuit configured to drive a physical quantity transducer; and a detection circuit to which first and second detection signals from the physical quantity transducer are input, wherein the detection circuit includes a gain adjustment amplifier configured by the first and second operational amplifiers and the first and second voltage division circuits and configured to receive an input of the first and second signals corresponding to

Assignees

• Seiko Epson Corp

Inventors

• Aoyama Takashi

Classifications

• H03F2203/45118

  At least one reactive element being added to at least one feedback circuit of a dif amp · CPC title

• H03F3/45076 Primary

  characterised by the way of implementation of the active amplifying circuit in the differential amplifier · CPC title

• H03F2200/129

  there being a feedback over the complete amplifier · CPC title

• H03K5/24

  the characteristic being amplitude · CPC title

• G01C19/5642 Primary

  using vibrating bars or beams · CPC title