Integrated electronic device including a full scale adjustment stage for signals supplied by a MEMS sensor

Patent metadata

Field	Value
Publication number	US-10921164-B2
Application number	US-201514975594-A
Country	US
Kind code	B2
Filing date	Dec 18, 2015
Priority date	Jun 18, 2015
Publication date	Feb 16, 2021
Grant date	Feb 16, 2021

Abstract

A MEMS sensor generates an output multiscale reading signal supplied to a full scale adjustment stage. The full scale adjustment stage includes a signal input configured to receive the reading signal, a saturation assessment block, and a full scale change block. The saturation assessment block is coupled to the signal input and configured to generate a scale increase request signal upon detection of a saturation condition. The full scale change block is coupled to the saturation assessment block and configured to generate a full scale change signal upon reception of the scale increase request signal.

First claim

The invention claimed is:

1. An electronic device, comprising:
a signal input configured to receive a reading signal produced by a MEMS sensor device that is subject to saturation; and
circuitry coupled to the signal input and configured to:
generate a saturation detection signal based on the reading signal produced by the MEMS sensor device;
generate a saturation prediction signal that predicts when saturation will occur based on the reading signal produced by the MEMS sensor device; and
generate a full scale change signal based on the saturation detection signal and the saturation prediction signal, wherein the full scale change signal, in operation, is provided to the MEMS sensor device and directs the MEMS sensor device to adjust its full scale in accordance with the full scale change signal.

2. The electronic device according to claim 1 , wherein the circuitry comprises:
a saturation detector.

3. The electronic device according to claim 2 , wherein the saturation detector comprises:
a comparator configured to compare the reading signal with at least one saturation threshold value and further configured to generate the saturation detection signal based on the comparison of the reading signal with the at least one saturation threshold value.

4. The electronic device according to claim 1 , wherein the circuitry comprises:
a saturation predictor configured to generate the saturation prediction signal.

5. The electronic device according to claim 4 , wherein the saturation predictor is configured to
generate a normalized signal sample;
store a previous normalized signal sample;
generate a predicted signal sample based on the normalized signal sample and the previous normalized signal sample; and
generate the saturation prediction signal if the predicted signal sample exceeds at least one normalization limit threshold.

6. The electronic device according to claim 1 wherein the circuitry is configured to:
compare the reading signal with a decrease threshold; and
generate a scale-decrease request signal based at least in part on the comparison of the reading signal with the decrease threshold.

7. The electronic device according to claim 6 , wherein the circuitry is configured to:
generate a full scale decrease request signal upon reception of a threshold number of scale decrease request signals.

8. The electronic device according to claim 6 , wherein the circuitry is configured to:
generate a first scale increase request signal upon reception of a threshold number of saturation prediction signals.

9. The electronic device according to claim 8 , wherein the circuitry is configured to:
generate a second scale increase request signal upon reception of a threshold number of saturation detection signals.

10. The electronic device according to claim 9 , wherein the circuitry is configured to generate a full scale increase signal when the scale-decrease request signal and at least one of the first scale increase signal and the second scale increase signal is received.

11. The electronic device according to claim 1 , wherein the circuitry is configured to:
output a replacement signal sample when a saturation condition of the reading signal is determined.

12. The electronic device according to claim 11 , wherein the circuitry is configured to:
store a previous normalized signal sample; and
generate the replacement signal sample based on a normalized signal sample and the previous normalized signal sample.

13. The electronic device according to claim 11 , wherein the circuitry is configured to:
store a normalized signal sample; and
use interpolation to generate the replacement signal sample based on the normalized signal sample and the previous normalized signal sample.

14. The electronic device according to claim 11 , wherein the circuitry is configured to:
amplify the replacement signal sample.

15. The electronic device according to claim 14 , wherein the circuitry is configured to select the reading signal or the replacement signal sample.

16. The electronic device according to claim 1 , wherein the reading signal is a digital signal and the circuitry is configured to process digital signals.

17. A sensing system, comprising:
a MEMS sensor having an input arranged to receive a full scale change signal and an output, wherein the MEMS sensor is arranged to adjust its full scale in accordance with the full scale change signal; and
signal processing circuitry coupled to the input and the output of the MEMS sensor and configured to:
generate an analog reading signal;
generate a digital reading signal based on the analog reading signal;
generate a saturation detection signal based on the digital reading signal;
generate a saturation prediction signal that predicts when saturation will occur based on at least one of the analog reading signal and the digital reading signal; and
generate the full scale change signal based on the saturation detection signal and the saturation prediction signal.

18. The sensing system according to claim 17 , wherein the MEMS sensor element and a first portion of the circuitry are formed in a first integrated circuit and a second portion of the circuitry is formed in a second integrated circuit.

19. The sensing system according to claim 17 , wherein the circuitry is configured to:
generate a replacement signal sample when a saturation condition of the digital reading signal is determined.

20. The sensing system according to claim 19 , wherein the circuitry is configured to:
generate an amplified signal.

21. A sensing system method, comprising:
producing a digitized reading signal with a MEMS sensor device; and
providing an amplified reading signal based on a full scale adjustment of the digitized reading signal, the full scale adjustment including:
generating a saturation detection signal based on the digitized reading signal;
generating a saturation prediction signal that predicts when saturation will occur based on the digitized reading signal;
generating a replacement control signal based on a saturation assessment of the digitized reading signal, the saturation assessment being based on the saturation detection signal and the saturation prediction signal;
applying the replacement control signal to select either a replacement signal or the digitized reading signal for amplification;
converting the selected one of the replacement signal and the digitized reading signal into the amplified reading signal; and
feeding a full scale adjustment signal back to the MEMS sensor device, wherein the MEMS sensor device is arranged to adjust its full scale in accordance with the full scale change signal.

22. The sensing system method according to claim 21 , wherein generating the replacement control signal comprises:
detecting when the digitized reading signal is outside of at least one saturation threshold value; and
producing, based on the detecting, the saturation detection signal.

23. The sensing system method according to claim 22 , wherein generating the replacement control signal comprises:
normalizing the digitized reading signal to produce a normalized signal;
storing the normalized signal in a memory;
generating a predicted value based on the normalized signal and a previous normalized signal; and
comparing the predicted value to at least one normalization limit threshold; and based on the comparison of the predicted value to the at least one normalization limit t

Assignees

• St Microelectronics Srl

Inventors

• Quartiroli Matteo

Classifications

• B81B7/008 Primary

  MEMS characterised by an electronic circuit specially adapted for controlling or driving the same (B81B7/0087 takes precedence; arrangements for starting, regulating, braking, or otherwise controlling an actuator H02N; control arrangements or circuits for visual indicators G09G3/00) · CPC title

• G01D5/56 Primary

  using electric or magnetic means · CPC title