Method and apparatus for generating a proof-mass drive signal

Patent metadata

Field	Value
Publication number	US-9503295-B2
Application number	US-201214440187-A
Country	US
Kind code	B2
Filing date	Nov 6, 2012
Priority date	Nov 6, 2012
Publication date	Nov 22, 2016
Grant date	Nov 22, 2016

Abstract

A drive-mode oscillator module generates at least one proof-mass drive signal for use within a micro-electro-mechanical system (MEMS) device. The drive-mode oscillator module comprises at least one gain control component arranged to receive at least one proof-mass motion measurement signal, and to generate a digital modulation control signal based at least partly on the at least one proof-mass motion measurement signal, and at least one modulation component arranged to receive the digital amplitude modulation control signal, and to output at least one proof-mass drive signal. The at least one modulation component is arranged to digitally modulate the at least one proof-mass drive signal based at least partly on the received digital amplitude modulation control signal.

First claim

The invention claimed is:

1. A drive-mode oscillator module for generating at least one proof-mass drive signal for use within a micro-electro-mechanical system (MEMS) device, the drive-mode oscillator module comprising:
at least one gain control component arranged to receive at least one proof-mass motion measurement signal, receive at least one reference amplitude signal, compare the at least one proof-mass motion measurement signal to the at least one reference amplitude signal, generate a digital modulation control signal based at least partly on the at least one proof-mass motion measurement signal, and output the digital modulation control signal comprising an indication of whether the at least one proof-mass motion measurement signal exceeds the at least one reference amplitude signal; and
at least one modulation component arranged to receive the digital modulation control signal, and to output at least one proof-mass drive signal, wherein the at least one modulation component is arranged to digitally modulate the at least one proof-mass drive signal based at least partly on the received digital modulation control signal.

2. A drive-mode oscillator module for generating at least one proof-mass drive signal for use within a micro-electro-mechanical system (MEMS) device, the drive-mode oscillator module comprising:
at least one gain control component arranged to receive at least one proof-mass motion measurement signal, and to generate a digital modulation control signal based at least partly on the at least one proof-mass motion measurement signal;
at least one modulation component arranged to receive the digital modulation control signal, and to output at least one proof-mass drive signal, wherein the at least one modulation component is arranged to digitally modulate the at least one proof-mass drive signal based at least partly on the received digital modulation control signal; and
at least one phase component arranged to:
receive the at least one proof-mass motion measurement signal;
detect a proof-mass motion phase; and
output to the at least one modulation component a digital phase signal,
wherein the at least one modulation component is further arranged to output the at least one proof-mass drive signal comprising a phase based at least partly on the received digital phase signal output by the at least one phase component.

3. The drive-mode oscillator module of claim 2 , wherein the at least one phase component is arranged to output the digital phase signal comprising a 90° phase shift relative to the detected proof-mass motion phase.

4. The drive-mode oscillator module of claim 3 , wherein the at least one phase component comprises a comparator arranged to:
receive a differential proof-mass motion measurement signal;
compare a first differential component of the differential proof-mass motion measurement signal to a second differential component of the differential proof-mass motion measurement signal; and
output a phase detection signal based at least partly on the comparison of the first and second differential components of the differential proof-mass motion measurement signal, wherein the phase component further comprises a phase shift component arranged to:
receive the phase detection signal output by the comparator;
apply a 90° phase shift to the phase detection signal; and
output the digital phase signal comprising the phase shifted phase detection signal.

5. The drive-mode oscillator module of claim 2 , wherein the modulation component comprises at least one level shifter arranged to receive the digital phase signal output by the at least one phase component, apply a voltage level shift to the received digital phase signal, and to output at least one proof-mass drive signal based at least partly on the level shifted digital phase signal.

6. The drive-mode oscillator module of claim 5 , wherein the at least one level shifter is configurable to apply a configurable voltage level shift to the received digital phase signal.

7. The drive-mode oscillator module of claim 1 , wherein the modulation component is arranged to apply amplitude shift keying (ASK) modulation to the at least one proof-mass drive signal based at least partly on the received digital modulation control signal.

8. The drive-mode oscillator module of claim 7 , wherein the modulation component is arranged to:
output a 90° phase shifted oscillating proof-mass drive signal upon the digital modulation control signal comprising an indication that the at least one proof-mass motion measurement signal is less than the at least one reference amplitude signal; and
output a constant voltage proof-mass drive signal upon the digital modulation control signal comprising an indication that the at least one proof-mass motion measurement signal exceeds the at least one reference amplitude signal.

9. The drive-mode oscillator module of claim 1 , wherein the modulation component is arranged to apply binary phase shift keying (BPSK) modulation to the at least one proof-mass drive signal based at least partly on the received digital modulation control signal.

10. The drive-mode oscillator module of claim 9 , wherein the modulation component is arranged to:
output a 90° phase shifted oscillating proof-mass drive signal upon the digital modulation control signal comprising an indication that the at least one proof-mass motion measurement signal is less than the at least one reference amplitude signal; and
output an inverted form of the 90° phase shifted oscillating proof-mass drive signal upon the digital modulation control signal comprising an indication that the at least one proof-mass motion measurement signal exceeds the at least one reference amplitude signal.

11. The drive-mode oscillator module of claim 1 , wherein the drive-mode oscillator module further comprises at least one analogue start-up component selectively arranged to generate a proof-mass drive signal for driving a proof-mass of the MEMS device during a start-up phase of the MEMS device.

12. A drive-mode oscillator module for generating at least one proof-mass drive signal for use within a micro-electro-mechanical system (MEMS) device, the drive-mode oscillator module comprising:
at least one gain control component arranged to receive at least one proof-mass motion measurement signal, and to generate a digital modulation control signal based at least partly on the at least one proof-mass motion measurement signal;
at least one modulation component arranged to receive the digital modulation control signal, and to output at least one proof-mass drive signal, wherein the at least one modulation component is arranged to digitally modulate the at least one proof-mass drive signal based at least partly on the received digital modulation control signal; and
at least one analogue start-up component selectively arranged to generate a proof-mass drive signal for driving a proof-mass of the MEMS device during a start-up phase of the MEMS device, wherein the at least one analogue start-up component comprises:
an integrator component arranged to receive the at least one proof-mass motion measurement signal and apply a 90° phase shift thereto; and
an amplifier component arranged to receive the phase shifted proof-mass motion measurement signal, and to output a proof-mass drive signal based at least partly on the phase shifted proof-mass motion measurement signal.

13. The drive-mode oscillator module of claim 1 , wherein the drive-mode oscillator module comprises at least one capacitance to voltage component arranged to receive a signal comprising an indication of a capacitance change of a MEMS drive measurement unit (

Assignees

• Cornibert Laurent
• Beaulaton Hugues
• Cassagnes Thierry
• Trauth Gerhard
• Freescale Semiconductor Inc

Inventors

• Cornibert Laurent
• Beaulaton Hugues
• Cassagnes Thierry
• Trauth Gerhard

Classifications

• G01C19/5726 Primary

  Signal processing · CPC title

• H04L27/125

  using a controlled oscillator in an open loop · CPC title

• H04L27/04 Primary

  Modulator circuits; Transmitter circuits · CPC title