Physical quantity sensor device and method of adjusting physical quantity sensor device

Patent metadata

Field	Value
Publication number	US-10126145-B2
Application number	US-201514642457-A
Country	US
Kind code	B2
Filing date	Mar 9, 2015
Priority date	Apr 16, 2014
Publication date	Nov 13, 2018
Grant date	Nov 13, 2018

Abstract

An analog signal is supplied to a first conversion section of a physical quantity sensor device, converted to digital, and set to be an initial output value of the first conversion section. Adjustment information for the first conversion section is calculated based on the error between the initial output value and a target output value of the first conversion section. Before an initial output value of a physical quantity sensor is measured for calculating initial setting information of a physical quantity sensor device, the first conversion section is adjusted based on the adjustment information. Also, a digital signal is supplied to a second conversion section of the physical quantity sensor device, converted to analog, and set to be an initial output value of the second conversion section. The second conversion section is adjusted based on adjustment information for the second conversion section.

First claim

What is claimed is:

1. A physical quantity sensor device, comprising:
a physical quantity sensor which outputs an electrical signal corresponding to a detected physical quantity;
an analog-to-digital (A/D) converter which converts an output value of the physical quantity sensor to digital;
a computing section connected to an output of the A/D converter and which carries out a digital computation for correcting the output value of the physical quantity sensor, converted to digital by the A/D converter, to a predetermined value;
a digital-to-analog (D/A) converter which converts a result computed by the digital computation to analog;
an analog input/output section connected to an output of the D/A converter and which outputs an output value of the D/A converter to an exterior;
a selector receiving as inputs an analog signal from the analog input/output section and the electrical signal from the physical quantity sensor, and having an output connected to the A/D converter, the selector configured to switch to selectively connect one of the analog input/output section or the physical quantity sensor to an input of the A/D converter to be converted by the A/D converter;
a storage section connected to the computing circuit and the D/A converter, the storage section storing adjustment information of the A/D converter based on the initial output value of the A/D converter, converted to digital by the A/D converter from a predetermined analog signal that is input to the A/D converter from the analog input/output section; and
a first correction section connected to the data storage section and the A/D converter, the first correction section for adjusting the output characteristic of the A/D converter on the basis of the adjustment information before the A/D converter converts the output value of the physical quantity sensor to digital.

2. The physical quantity sensor device according to claim 1 , further comprising:
an acquisition section which acquires an initial output value of the physical quantity sensor,
wherein the computing section carries out the digital computation based on the initial output value of the physical quantity sensor converted to digital by the A/D converter.

3. The physical quantity sensor device according to claim 1 , wherein
the adjustment information is based on the error between the initial output characteristic of the A/D converter and a target output characteristic of the A/D converter.

4. The physical quantity sensor device according to claim 1 , further comprising:
a second correction section connected to the D/A converter for adjusting the output characteristic of the D/A converter on the basis of the adjustment information before the D/A converter converts the computed result to analog,
wherein the storage section storing adjustment information based on the initial output characteristic of the D/A converter, converted to analog by the D/A converter from a predetermined digital signal that is input to the D/A converter from the exterior through the digital input/output section.

5. A physical quantity sensor device, comprising:
a physical quantity sensor which outputs an electrical signal corresponding to a detected physical quantity;
a A/D converter connected to an output of the physical quantity sensor and which converts an output value of the physical quantity sensor to digital;
a computing section connected to an output of the A/D converter and which carries out a digital computation for correcting the output value of the physical quantity sensor, converted to digital by the A/D converter, to a predetermined value;
a D/A converter which converts a result computed by the digital computation to analog;
a digital input/output section connected to an output of the D/A converter and configured to communicate digitally with a device external to the physical quantity sensor device;
a storage section connected to the computing circuit and the D/A converter, the storage section storing adjustment information based on the initial output characteristic of the D/A converter, converted to analog by the D/A converter from a predetermined digital signal that is input to the D/A converter from an exterior through the digital input/output section; and
a first correction section connected to the D/A converter for adjusting the output characteristic of the D/A converter on the basis of the adjustment information before the D/A converter converts the computed result to analog.

6. The physical quantity sensor device according to claim 5 , further comprising:
an acquisition section which acquires an initial output value of the physical quantity sensor,
wherein the computing section carries out the digital computation based on the initial output value of the physical quantity sensor converted to digital by the A/D converter.

7. A method for adjusting a physical quantity sensor device that includes: a physical quantity sensor which outputs an electrical signal corresponding to a detected physical quantity; an A/D converter which converts an output value of the physical quantity sensor to digital; a computing section connected to an output of the A/D converter and which carries out a digital computation for correcting the output value of the physical quantity sensor, converted to digital by the A/D converter, to a predetermined value; a D/A converter which converts a result computed by the digital computation to analog; and an analog input/output section which outputs an output value of the D/A converter to an exterior, the method for adjusting the physical quantity sensor device, comprising:
acquiring the initial output characteristic of the A/D converter by controlling a selector connected between the physical quantity sensor and the A/D converter to electrically connect the A/D converter to the analog input/output section and by converting a predetermined analog signal input from the analog input/output section to the A/D converter to digital through the A/D converter;
adjusting the output characteristic of the A/D converter on the basis of the initial output characteristic of the A/D converter before converting the output value of the physical quantity sensor to digital through the A/D converter;
switching the selector to connect the A/D converter to the physical quantity sensor; and
converting the output value of the physical quantity sensor to digital through the A/D converter after electrically connecting the A/D converter to the physical quantity sensor by the selector and after adjusting the output characteristic of the A/D converter.

Assignees

• Fuji Electric Co Ltd

Inventors

• Nishikawa Mutsuo
• Uematsu Katsuyuki
• Matsunami Kazuhiro

Classifications

• G01D3/022

  having an ideal characteristic, map or correction data stored in a digital memory · CPC title

• G01D3/0365 Primary

  the undesired influence being measured using a separate sensor, which produces an influence related signal · CPC title

• H03M1/10

  Calibration or testing · CPC title