Power optimized driving signal switching scheme for oscillating MEMS mirrors

Patent metadata

Field	Value
Publication number	US-12044841-B2
Application number	US-202117238396-A
Country	US
Kind code	B2
Filing date	Apr 23, 2021
Priority date	Apr 23, 2021
Publication date	Jul 23, 2024
Grant date	Jul 23, 2024

Abstract

An oscillator driver system includes an oscillator structure and a driver circuit. The oscillator structure includes a rotor terminal configured to receive a rotor voltage and a stator terminal configured to receive a stator voltage, and is driven about a rotation axis according to a voltage difference between the rotor and stator voltages. The driver circuit is configured to generate a driving signal and output the driving signal as the rotor voltage, wherein the driving signal toggles between low and high voltage levels at an actuation frequency to drive the oscillator structure about the rotation axis, and wherein the stator voltage is a fixed voltage. The low and high voltage levels are greater than the stator voltage such that the voltage difference toggles between a low voltage difference and a high voltage difference as the driving signal toggles between the low voltage level and the high voltage level, respectively.

First claim

What is claimed is:

1. An oscillator driver system, comprising:
an oscillator structure configured to oscillate about a rotation axis, wherein the oscillator structure comprises a rotor terminal configured to receive a rotor voltage and a stator terminal configured to receive a stator voltage, and wherein the oscillator structure is driven about the rotation axis according to a voltage difference between the rotor voltage and the stator voltage; and
a driver circuit comprising an output terminal coupled to the rotor terminal,
wherein the driver circuit is configured to generate a driving signal and output the driving signal at the output terminal as the rotor voltage,
wherein the driving signal toggles between a low voltage level and a high voltage level at an actuation frequency to drive the oscillator structure about the rotation axis,
wherein the stator voltage is a fixed voltage and a magnitude of the low voltage level and a magnitude of the high voltage level are both greater than a magnitude of the stator voltage such that a voltage difference toggles between a low voltage difference and a high voltage difference as the driving signal toggles between the low voltage level and the high voltage level, respectively.

2. The oscillator driver system of claim 1 , wherein:
the driver circuit is configured to receive a first supply voltage and a second supply voltage, and
the driver circuit comprises a voltage multiplier circuit configured to generate the driving signal at the output terminal, wherein the voltage multiplier circuit is configured to output the first supply voltage as the low voltage level of the driving signal and apply a multiplier to the first supply voltage in order to generate a multiple of the first supply voltage as the high voltage level of the driving signal.

3. The oscillator driver system of claim 2 , wherein the voltage multiplier circuit is a voltage doubler configured to double the first supply voltage and output the doubled first supply voltage as the high voltage level of the driving signal.

4. The oscillator driver system of claim 2 , wherein the stator voltage is fixed at the second supply voltage.

5. The oscillator driver system of claim 2 , wherein the second supply voltage is ground.

6. The oscillator driver system of claim 2 , further comprising:
a controller configured to generate a control signal that toggles between a first control value and a second control value at the actuation frequency at which the driving signal toggles between the low voltage level and the high voltage level,
wherein the voltage multiplier circuit is configured to receive the control signal and toggle the driving signal between the low voltage level and the high voltage level according to the control signal.

7. The oscillator driver system of claim 6 , wherein the voltage difference is set to the low voltage difference in response to the control signal having the first control value and the voltage difference is set to the high voltage difference in response to the control signal having the second control value.

8. The oscillator driver system of claim 6 , wherein the voltage multiplier circuit comprises a diode-capacitor circuit that defines the multiplier of the first supply voltage.

9. The oscillator driver system of claim 8 , wherein the voltage multiplier circuit comprises a transistor half-bridge configured to receive the control signal and charge a capacitor of the diode-capacitor circuit when the control signal has the first control value and supply a stored voltage of the capacitor to the rotor terminal when the control signal has the second control value.

10. The oscillator driver system of claim 2 , wherein the voltage multiplier circuit comprises:
a diode-capacitor circuit configured to generate the driving signal, wherein the diode-capacitor circuit defines the multiplier of the first supply voltage; and
a transistor half-bridge configured to control the diode-capacitor circuit to generate the driving signal at the actuation frequency.

11. An oscillator driver system, comprising:
an oscillator structure configured to oscillate about a rotation axis, wherein the oscillator structure comprises a rotor terminal configured to receive a rotor voltage and a stator terminal configured to receive a stator voltage, and wherein the oscillator structure is driven about the rotation axis according to a voltage difference between the rotor voltage and the stator voltage; and
a driver circuit comprising a first output terminal coupled to the rotor terminal and a second output terminal coupled to the stator terminal,
wherein the driver circuit is configured to generate a driving signal and output the driving signal at the second output terminal as the stator voltage,
wherein the driving signal toggles between a low voltage level and a high voltage level at an actuation frequency to drive the oscillator structure about the rotation axis,
wherein the rotor voltage is a fixed voltage and a magnitude of the low voltage level and a magnitude of the high voltage level are both less than a magnitude of the rotor voltage such that a voltage difference toggles between a low voltage difference and a high voltage difference as the driving signal toggles between the high voltage level and the low voltage level, respectively.

12. The oscillator driver system of claim 11 , wherein:
the driver circuit is configured to receive a first supply voltage and a second supply voltage, and
the driver circuit comprises a voltage multiplier circuit configured to generate the rotor voltage at the first output terminal and the driving signal at the second output terminal, wherein the voltage multiplier circuit is configured to apply a multiplier to the first supply voltage in order to generate a multiple of the first supply voltage as the rotor voltage.

13. The oscillator driver system of claim 12 , wherein the voltage multiplier circuit is a voltage doubler configured to double the first supply voltage and output the doubled first supply voltage as the rotor voltage.

14. The oscillator driver system of claim 12 , wherein the voltage multiplier circuit is configured to output the first supply voltage at the second output terminal as the high voltage level of the driving signal and output the second supply voltage at the second output terminal as the low voltage level of the driving signal.

15. The oscillator driver system of claim 14 , wherein the second supply voltage is ground.

16. The oscillator driver system of claim 14 , further comprising:
a controller configured to generate a control signal that toggles between a first control value and a second control value at the actuation frequency at which the driving signal toggles between the low voltage level and the high voltage level,
wherein the voltage multiplier circuit is configured to receive the control signal and toggle the driving signal between the low voltage level and the high voltage level according to the control signal.

17. The oscillator driver system of claim 16 , wherein the voltage difference is set to the high voltage difference in response to the control signal having the first control value and the voltage difference is set to the low voltage difference in response to the control signal having the second control value.

18. The oscillator driver system of claim 16 , wherein the voltage multiplier circuit comprises a diode-capacitor circuit that defines the multiplier of the first supply voltage.

19. The oscillator driver system of claim 18 , wherein the voltag

Assignees

• Infineon Technologies Ag

Inventors

• Druml Norbert
• Greiner Philipp

Classifications

• H03B5/30 Primary

  with frequency-determining element being electromechanical resonator · CPC title

• G02B26/0841 Primary

  the reflecting element being moved or deformed by electrostatic means · CPC title

• G02B26/101 Primary

  with both horizontal and vertical deflecting means, e.g. raster or XY scanners (colour television using laser beams scanning a display screen H04N9/3129) · CPC title