PIEZO DRIVER HAVING PASSIVE ENERGY STORAGE COMPONENT RECHARGING CAPABILITY

• US 20140070665A1
• Filed: 09/11/2012
• Published: 03/13/2014
• Est. Priority Date: 09/11/2012
• Status: Active Grant

• Current Assignee: Maxim Integrated Products, Inc. (Analog Devices, Inc.)
• Original Assignee: Maxim Integrated Products, Inc. (Analog Devices, Inc.)
• Inventors: Muggler, Patrick, Doy, Anthony S.
• Granted Patent: US 9,652,013 B2
• Time in Patent Office: Days
• US Class Current: 310/314
• CPC Class Codes: G06F 1/32 Means for saving power
• CPC Class Codes: G06F 3/016 Input arrangements with force or tactile feedback as computer generated output to the user
• CPC Class Codes: H10N 30/802 Circuitry or processes for operating piezoelectric or electrostrictive devices not otherwise provided for, e.g. drive circuits

Abstract

A piezo driver is described that is configured to furnish electric charge to a piezo component during a first operational state and configured to transfer electric charge from the piezo component to a passive energy storage component during a second operational state. In one or more implementations, the piezo driver includes a passive energy storage component configured to store electric charge. The piezo driver also includes a voltage converter configured to electrically connect between a piezo component and the passive energy storage component. The voltage converter is configured to furnish electric charge from the passive energy storage component to the piezo component during a first state of operation and configured to furnish electric charge from the piezo component to the passive energy storage component during a second state of operation.

Claims

1. A piezo driver comprising:

a passive energy storage component configured to store electric charge; and

a voltage converter configured to electrically connect between a piezo component and the passive energy storage component, the voltage converter configured to furnish electric charge from the passive energy storage component to the piezo component during a first state of operation and to furnish electric charge from the piezo component to the passive energy storage component during a second state of operation, the first state of operation different from the second state of operation.

2. The piezo driver as recited in claim 1, wherein the passive energy storage component comprises a capacitor.

3. The piezo driver as recited in claim 1, further comprising a charge pump electrically connected to the passive energy storage component, the charge pump configured to generate an output voltage greater in value than an input voltage, the passive energy storage component configured to store an electric charge such that a voltage across the capacitor approximately equals the output voltage.

4. The piezo driver as recited in claim 1, further comprising at least a first switch and a second switch, the first switch and the second switch each having an open configuration and a close configuration, the first switch configured to electrically connect between the voltage converter and the piezo component, the second switch configured to electrically connect between the piezo component and ground potential.

5. The piezo driver as recited in claim 4, further comprising a control module electrically connected to the first switch and the second switch, the control module configured to cause the first switch and the second switch to transition between the open configuration and the closed configuration.

6. The piezo driver as recited in claim 5, further comprising a feedback component configured to electrically connect in parallel with the piezo component and configured to electrically connect to the control module, the feedback component configured to measure a voltage value across the piezo component and furnish a signal representing the voltage value to the control module, wherein the control module is configured to transition the first switch and the second switch between the open configuration and the closed configuration based upon the signal representing the voltage value.

7. The piezo driver as recited in claim 4, wherein at least one of the first switch or the second switch comprise a metal-oxide-semiconductor field-effect transistor (MOSFET).

8. The piezo driver as recited in claim 7, wherein at least one of the first switch or the second switch comprise an n-type MOSFET.

9. An electronic device comprising:

a piezo component;

a capacitor configured to store electric charge; and

a voltage converter electrically connected between the piezo component and the capacitor, the voltage converter configured to furnish electric charge from the passive energy storage component to the piezo component during a first state of operation and to furnish electric charge from the piezo component to the passive energy storage component during a second state of operation, the first state of operation different from the second state of operation.

10. The electronic device as recited in claim 9, further comprising a charge pump electrically connected to the capacitor, the charge pump configured to generate an output voltage greater in value than an input voltage, the capacitor configured to store an electric charge such that a voltage across the capacitor approximately equals the output voltage.

11. The electronic device as recited in claim 9, further comprising at least a first switch and a second switch, the first switch and the second switch each having an open configuration and a close configuration, the first switch electrically connected between the voltage converter and the piezo component, the second switch electrically connected between the piezo component and ground potential.

12. The electronic device as recited in claim 11, further comprising a control module electrically connected to the first switch and the second switch, the control module configured to cause the first switch and the second switch to transition between the open configuration and the closed configuration.

13. The electronic device as recited in claim 12, further comprising a feedback component electrically connected in parallel with the piezo component and electrically connected to the control module, the feedback component configured to measure a voltage value across the piezo component and furnish a signal representing the voltage value to the control module, wherein the control module is configured to transition the first switch and the second switch between the open configuration and the closed configuration based upon the signal representing the voltage value.

14. The electronic device as recited in claim 11, wherein at least one of the first switch or the second switch comprise a metal-oxide-semiconductor field-effect transistor (MOSFET).

15. The electronic device as recited in claim 11, wherein at least one of the first switch or the second switch comprise an n-type MOSFET.

16. A method comprising:

determining whether to increase a voltage across the piezo component;

generating a control signal to cause one or more switches to transition to another desired configuration to allow a transfer of electric charge from the passive energy storage component to the piezo component when the voltage across the piezo component is to be increased;

determining whether to reduce a voltage across a piezo component; and

generating a control signal to cause one or more switches to transition to a desired configuration to allow a transfer of electric charge from the piezo component to a passive energy storage component when the voltage across the piezo component is to be reduced;

17. The method as recited in claim 16, wherein the one or more switches comprise metal-oxide-semiconductor field-effect transistors (MOSFETs).

18. The method as recited in claim 17, wherein the one or more switches comprise n-type MOSFETs.

19. The method as recited in claim 16, wherein the passive energy storage component comprises a capacitor.

20. The method as recited in claim 16, wherein determining whether a voltage across the piezo component needs to be reduced includes comparing an input signal to a signal representing the voltage across the piezo component, wherein the signal representing the voltage across the piezo component is measured by a feedback component.