Measuring a noise level of an accelerometer

Patent metadata

Field	Value
Publication number	US-11255876-B2
Application number	US-202016824161-A
Country	US
Kind code	B2
Filing date	Mar 19, 2020
Priority date	Mar 22, 2019
Publication date	Feb 22, 2022
Grant date	Feb 22, 2022

Abstract

A method of measuring noise of an accelerometer can comprise exposing the accelerometer comprising a micro-electro-mechanical system (MEMS) component coupled to an application specific integrated circuit component (ASIC), to an external environmental input, with the MEMS component being configured to provide a first output to the ASIC based on the external environmental input. The method can further comprise estimating a first noise generated by operation of the MEMS component, and replacing the first output provided to the ASIC from the MEMS component, with a second output generated by a MEMS emulator component, with the second output comprising the first noise. Further, the method can include generating an output of the accelerometer based on the second output processed by the ASIC.

First claim

What is claimed is:

1. An accelerometer, comprising:
an electronic sensing component;
a micro-electro-mechanical system (MEMS) component associated with the electronic sensing component, wherein the MEMS component receives environment noise and external acceleration;
a MEMS emulation component configured to emulate the MEMS component;
a noise estimating component configured to:
generate an estimate of Brownian noise of the MEMS component;
replace a first output of the accelerometer, with a second output of the accelerometer generated by the MEMS emulation component, wherein the second output comprises a sum of the noise associated with the electronic sensing component and the estimate of the Brownian noise, wherein estimating the Brownian noise comprises:
applying a step signal to the MEMS component, and
determining a resonant frequency and a quality factor characteristic of the MEMS component by applying a least square fit method to a response by the MEMS component to the step signal.

2. The accelerometer of claim 1 , wherein the estimate of Brownian noise comprises an estimate of Brownian noise generated by operation of the MEMS component.

3. The accelerometer of claim 1 , wherein the noise estimating component is configured to generate the estimate of the Brownian noise when a switch connects the MEMS component to the electronic sensing component and disables the MEMS emulation component from the electronic sensing component.

4. The accelerometer of claim 1 , wherein the noise estimating component generates the estimate of the Brownian noise based on characteristics of the MEMS component.

5. The accelerometer of claim 4 , wherein the characteristics of the MEMS component comprise a size of an actuator of the MEMS component.

6. The accelerometer of claim 1 , wherein the environment noise comprises the environment noise during production of the accelerometer.

7. A method, comprising:
exposing an accelerometer comprising a micro-electro-mechanical system (MEMS) component coupled to an application specific integrated circuit component (ASIC), to an external environmental input, wherein the MEMS component is configured to provide a first output to the ASIC based on the external environmental input;
estimating a first noise comprising estimated Brownian noise generated by operation of the MEMS component;
replacing the first output provided to the ASIC from the MEMS component, with a second output generated by a MEMS emulator component, wherein the second output comprises the first noise; and
generating an output of the accelerometer based on the second output processed by the ASIC, wherein estimating the first noise comprises:
applying a step signal to the MEMS component, and
determining a resonant frequency and a quality factor characteristic of the MEMS component by applying a least square fit method to a response by the MEMS component to the step signal.

8. The method of claim 7 , wherein the estimating the first noise is further based on characteristics of the MEMS component comprising a size of an actuator of the MEMS component.

9. The method of claim 7 , wherein the output of the accelerometer further comprises a second noise resulting from the processing of the second output by the ASIC.

10. The method of claim 9 , wherein the second noise comprises electrical noise resulting from the processing of the second output.

11. The method of claim 7 , wherein the output of the accelerometer comprises a noise level of the accelerometer.

12. The method of claim 11 , wherein the noise level of the accelerometer comprises the noise level during production of the accelerometer.

13. The method of claim 7 , wherein the second output generated by the MEMS emulator component comprises an emulation of output of the MEMS component without exposure of the MEMS component to the external environmental input.

Assignees

• Invensense Inc

Inventors

• Dakshinamurthy Sriraman
• Thompson Matthew Julian
• Tsinker Vadim

Classifications

• G01P21/00 Primary

  Testing or calibrating of apparatus or devices covered by the preceding groups · CPC title

• G01P15/125

  by capacitive pick-up · CPC title

• G01P15/0802

  Details · CPC title