RECHARGEABLE PIEZO DRIVER

Abstract

Piezo driver (100), comprising: a first passive energy storage component (122, 123) and a second passive energy storage component (122, 123), wherein the first passive energy storage component (122, 123) and the second passive energy storage component (122, 123) are configured to store electrical charge; a voltage converter (128) configured for electrical connection between a piezo component (102) and the first passive energy storage component (122, 123) and the second passive energy storage component (122, 123), wherein the voltage converter (128) is configured to supply electrical charge from the first passive energy storage component (122, 123) to the piezo component (102) during a first operating state and to supply electrical charge from the piezo component (102) to the first passive energy storage component (122, 123) during a second operating state, and the voltage converter (128) is configured to supply electrical charge from the second passive energy storage component (122, 123) to the piezo component (102) during a third operating state and to supply electrical charge from the piezo component (102) to the second passive energy storage component during a fourth operating state (122, 123) to deliver; and a dual output charge pump (114) electrically connected to the first passive energy storage component (122, 123) and the second passive energy storage component (122, 123), wherein the dual output charge pump (114) is configured to generate a first output voltage and a second output voltage that are greater in absolute value than an input voltage supplied to the dual output charge pump (114), wherein the first passive energy storage component (122, 123) is configured to store an electrical charge such that a voltage across the first passive energy storage component (122, 123) is approximately equal to the first output voltage, and the second passive energy storage component (122, 123) is configured to store an electrical charge such that a voltage across the second passive energy storage component (122, 123) is approximately equal to the second output voltage.

Description

background

[0001] Electronic devices such as smartphones, tablet computers, and so on often incorporate touch screens to receive user input. A touch screen is a display that can detect the presence, location, or pressure associated with a touch within the screen area, such as a finger, hand, stylus, or other pointing device. These touch screens can use piezoelectric components, such as piezoelectric sensors configured to utilize the piezoelectric effect to measure mechanical pressure, acceleration, force, and so on. Disclosures relevant to the present invention can be found in the documents DE 198 58 286 A1, DE 198 58 250 A1, EP 2 128 415 A1, US 2009 / 0 121 724 A1, US 2007 / 0 103 033 A1, DE 197 14 607 A1, DE 198 14 594 A1 and DE 197 23 932 C1.DE 198 58 286 A1 discloses a method and a device for charging or discharging a piezoelectric element. This occurs through charge transport between a capacitive element and the piezoelectric element. Several capacitive elements are provided. The capacitive element to be used can be selectively selected. The selection is made depending on the charge state of the piezoelectric element, the desired course, or the extent of the charging or discharging. A similar disclosure can be found in DE 198 58 250 A1. There, a method and a device for charging and discharging a piezoelectric element are also disclosed. Charging and discharging occurs through charge transport between a capacitive element and the piezoelectric element. Several capacitive elements are provided. The capacitive element to be used can also be selectively selected here.The capacitive elements selectable for charging differ at least partially from the elements selectable for discharging. EP 2 128 415 A1 discloses a method for controlling the displacement of a stack of a piezoelectric actuator in a fuel injector. The fuel flow is regulated by charging or discharging the stack with varying current during an opening and / or closing phase. The phase comprises a first and a second stage. In the first stage, a first current is applied for a specific time. In the second stage, a lower second current is applied for a second time. US 2009 / 0 121 724 A1 discloses a method for fault detection in an injector arrangement with piezoelectric fuel injectors. A driver circuit controls the injectors. The method comprises determining a sample voltage at a first time.Subsequently, a range of predicted voltages is calculated for a second point in time. A deviation of the measured voltage from the predicted range indicates an error. US 2007 / 0 103 033 A1 discloses a driver circuit for an injector arrangement with at least one piezoelectric injector. The circuit comprises two charge storage devices. A first charge storage device discharges current to initiate an injection process. A second charge storage device charges current to terminate the injection process. Switching elements control the connection of the charge storage devices to the injector. At the end of the charging phase, a charging device transfers charge for later use. DE 197 14 607 A1 discloses a method and a device for charging or discharging a piezoelectric element in several stages. The charging or discharging takes place partly via an element acting as a resistor and partly via an element acting as an inductor.This allows the charging and discharging process to be influenced as desired with minimal power loss. DE 198 14 594 A1 discloses a method and a device for charging or discharging a piezoelectric element. The charging or discharging process is terminated before the desired voltage is reached. This allows the piezoelectric element to be charged or discharged precisely. Because the current does not drop abruptly, further charging or discharging occurs even after the process has ended. DE 197 23 932 C1 discloses a method for controlling a capacitive actuator. The actuator capacitance is determined from the supplied charge quantity and the actuator voltage. The supplied energy is calculated based on these values. The charging voltage is regulated so that the energy corresponds to a predetermined target value. Summary

[0002] A piezo driver is described that is configured to supply electrical charge to a piezo component and is configured to transfer electrical charge from the piezo component to a passive energy storage component during various operating states of the piezo driver. The piezo driver includes a first passive energy storage component and a second passive energy storage component configured to store electrical charge. The piezo driver also includes a voltage converter configured to electrically connect a piezo component to the first passive energy storage component and the second passive energy storage component. The voltage converter is configured to supply electrical charge from the first passive energy storage component to the piezo component during a first operating state and to supply electrical charge from the piezo component to the first passive energy storage component during a second operating state.The voltage converter is also configured to supply electrical charge from the second passive energy storage component to the piezo component during a third operating state and to supply electrical charge from the piezo component to the second passive energy storage component during a fourth operating state. The piezo driver further includes a dual-output charge pump electrically connected to the first passive energy storage component and the second passive energy storage component. The dual-output charge pump is configured to generate a first output voltage and a second output voltage that are greater in absolute value than an input voltage supplied to the dual-output charge pump.The first passive energy storage device is further configured to store an electrical charge such that a voltage across the first passive energy storage device is approximately equal to the first output voltage, and the second passive energy storage device is configured to store an electrical charge such that a voltage across the second passive energy storage device is approximately equal to the second output voltage. Drawings

[0003] The detailed description is provided with reference to the accompanying figures. The use of the same reference numerals in various instances in the description and the figures may refer to similar or identical elements. Fig. 1A is a block diagram illustrating a piezo driver according to an embodiment of the present disclosure. Fig. 1B is a circuit diagram illustrating a piezo driver according to a particular embodiment of the present disclosure. Fig. 2 is a flowchart illustrating a method for at least partially recharging an energy storage device via a piezo device in a piezo driver, such as the one shown in Fig. 1A and Fig. 1B, according to an embodiment of the present disclosure. Detailed descriptionOverview

[0004] Haptic feedback technology may include piezo devices (e.g., piezoelectric devices) configured to generate a vibration in response to an electrical signal to provide haptic and / or audible feedback. For example, piezo drivers are used to drive a piezo device during operation of a mobile computing device. Piezo drivers typically build up a voltage across the piezo devices by driving current into the piezo device to build up electrical charge across the device. Under certain conditions, a control module determines that a voltage drop across the piezo device is necessary. Under these conditions, the piezo drivers drain the stored electrical charge to ground. When the piezo device generates haptic and / or audible feedback, the voltage across the piezo device often increases and decreases, causing inefficient use of the electrical charge.

[0005] Accordingly, a piezo driver is described that is configured to supply electrical charge to a piezo component and is configured to transfer electrical charge from the piezo component to a passive energy storage component during various operating states of the piezo driver. The piezo driver includes a piezo component and a first passive energy storage component and a second passive energy storage component configured to store electrical charge. In one or more embodiments, the first and second energy storage components comprise capacitors. The piezo driver also includes a voltage converter configured for electrical connection between a piezo component and the first passive energy storage component and the second passive energy storage component.The voltage converter is configured to supply electrical charge from the first passive energy storage component to the piezo component during a first operating state and to supply electrical charge from the piezo component to the first passive energy storage component during a second operating state. The voltage converter is also configured to supply electrical charge from the second passive energy storage component to the piezo component during a third operating state and to supply electrical charge from the piezo component to the second passive energy storage component during a fourth operating state. The piezo driver further includes a dual-output charge pump electrically connected to the first passive energy storage component and the second passive energy storage component.The dual-output charge pump is configured to generate a first output voltage and a second output voltage that are greater in absolute value than an input voltage supplied to the dual-output charge pump. The first passive energy storage device is further configured to store an electrical charge such that a voltage across the first passive energy storage device is approximately equal to the first output voltage, and the second passive energy storage device is configured to store an electrical charge such that a voltage across the second passive energy storage device is approximately equal to the second output voltage. In one embodiment, the piezo driver is incorporated into an electronic device that includes a piezo device.In some arrangements, the piezo driver according to the present disclosure can improve efficiency by at least twenty percent (20%) compared to the efficiency of piezo drivers that shunt the electrical charge to ground. Example piezo drivers

[0006] The Fig. 1A and Fig. 1B illustrate a piezo driver 100 according to embodiments of the present disclosure. As shown, the piezo driver 100 is configured to drive a piezo component 102 and reuse charge in the driver 100. The driver 100 may be incorporated into an electronic device including a piezo component 102, which may be used to generate haptic or audible feedback in electronic devices such as smartphones, tablet computers, laptops, and so on (e.g., electronic devices with touch screens for receiving user input). In certain embodiments, the piezo component 102 may comprise a piezo audio amplifier, a haptic piezo driver, a piezo motor driver, or the like, configured to provide haptic signals, audible signals, combinations thereof, or the like in response to one or more electrical signals.The functionality may enable the generation of tactile and / or audible feedback (e.g., the touch screen of a computing device provides tactile and / or audible feedback). In one embodiment, the piezoelectric component 102 is fabricated from suitable piezoelectric materials, which may include, but are not limited to, series and bimorph piezoelectric materials.

[0007] The piezo driver 100 contains a feedback component 104, which is connected via the terminals (e.g. contacts, electrodes) 106, 108 (see Fig. 1B) of a passive energy component 109. (E.g., the feedback component 104 is electrically connected in parallel to the passive energy component 109.) The feedback component 104 represents functionality to measure the voltage across the passive energy component 109 and provide a signal representing the measured voltage (i.e., the measured voltage signal) to a control module 110. The feedback component 104 can be configured in a variety of ways. For example, the feedback component 104 can consist of a circuit (e.g., a differential amplifier, etc.), software (e.g., computer-executable instructions), firmware, combinations thereof, or the like, and configured to measure the voltage across the passive energy storage component 109. In a particular embodiment, as shown in Fig. As shown in Figure 1B, the passive energy component 109 is an inductor. As described in more detail herein, the inductor serves to form a voltage converter that operates either as a boost converter or a buck converter during various phases of operation of the piezo driver 100.

[0008] The control module 110 provides functionality to determine a desired operating state of the driver 100 and to generate control signals based at least in part on the measured voltage signal from the feedback component 104 (e.g., based on the desired operating state). In one or more embodiments, the control module 110 also consists of circuitry, software, firmware, combinations thereof, or the like. The control module 110 also receives an input signal at input signal port 112, which is electrically connected to the control module 110. The input signal is generated by an external source (e.g., a source external to the driver 100), such as an application sensor, a touch screen, a digital-to-analog converter (e.g., an audio digital-to-analog converter), or the like. The input signal represents a detection of an event, such as a measurement of the input detected by the external source (e.g.,a user's touch on the touch screen, a user's input on the application sensor, etc.). Once the control module 110 receives the input signal, the control module 110 is configured to compare the input signal with the signal representing the measured voltage across the piezo component 102. Based on the comparison of the input signal and the measured voltage signal, the control module 110 is configured to determine a state of the piezo component 102, which is described in more detail below.

[0009] As shown, the piezo driver 100 also includes a dual-output charge pump 114 (e.g., a boost converter) configured to generate (e.g., source, output) an output voltage whose absolute value is greater than that of the input voltage. In a particular embodiment, the dual-output charge pump 114 is a direct current (DC / DC) power (boost) converter that converts a DC voltage source from one voltage level (e.g., voltage value) to another. For example, the charge pump 114 may be connected to a power source, such as the battery of a mobile computer, via a power source terminal 116. The charge pump 114 receives an input voltage from the power source and is configured to generate an output voltage whose absolute value is greater than the input voltage of the power source.

[0010] The charge pump 114 includes output terminals 118, 119, 120 that are electrically connected to passive energy storage components 122, 123. More specifically, the output terminal 118 is connected to the terminal 124A of the passive energy storage component 122, the output terminal 119 is connected to the terminal 124B of the passive energy storage component 122 and the passive energy storage component 123, and the output terminal 120 is connected to the terminal 124C of the passive energy storage component 123. The terminals 124A, 124C comprise the non-grounded terminals of the passive energy storage components 122 and 123, respectively, and the terminal 124B comprises the ground terminal common to both passive energy storage components 122, 123. The passive energy storage components 122, 123 are configured to store energy (e.g., to store electrical charge). In a particular embodiment, the passive energy storage components 122, 123 are capacitors (see Fig. 1B). Thus, charge pump 114 supplies the output voltage, causing an amount of electrical charge to be stored in passive energy storage devices 122, 123 such that the voltage across devices 122, 123 is approximately equal to the output voltages of charge pump 114. For example, dual-output charge pump 114 is configured to produce an output of + / - 30 V. Thus, the voltage produced between terminals 124A and 124B is approximately thirty volts (30 V), and the voltage produced between terminals 124C and 124B is approximately minus thirty volts (-30 V).Thus, the passive energy storage device 122 is configured to store an electrical charge approximately equal to a positive voltage supplied by the dual output charge pump 114, and the passive energy storage device 123 is configured to store an electrical charge approximately equal to a negative voltage supplied by the dual output charge pump 114. In one embodiment, as shown in FIGS. Fig. 1A and Fig. 1B, the control module 110 is also electrically connected to the passive energy storage components 122, 123 via connections (e.g., contacts, electrodes) 126A and 126B, respectively, for monitoring the voltage across the passive energy storage components 122, 123. For example, if the voltage across either the passive energy storage component 122 or the passive energy storage component 123 is too low (as an absolute value), the control module 110 is configured to cause the charge pump 114 and / or the power source (e.g., the power source connected to the power source terminal 116) to effect recharging of the passive energy storage components 122, 123.

[0011] As in Fig. 1A, the piezo driver 100 also includes a voltage converter 128 configured to convert voltage from a first voltage level to a second voltage level.

[0012] As described above and as in Fig. 1B, the passive energy component 109 forms part of the voltage converter 128. In addition, the driver 100 contains multiple transistors that form the remaining part of the voltage converter 128 (see Fig. 1B). In one embodiment, driver 100 includes transistors 129, 130, 131, 132, and transistors 129, 130, 131, 132 are configured, in combination with passive energy component 109, to form part of voltage converter 128 during various operating states of driver 100. Thus, transistors 129, 130, 131, 132 and inductor 109 are connected in series, and inductor 109 is connected in series with piezo component 102. In one embodiment, transistors 129, 130, 131, 132 are metal-oxide-semiconductor field-effect transistors (MOSFETs). For example, each of the MOSFET devices described herein comprises n-type MOSFET devices. In another example, each of the MOSFET devices described herein comprises p-type MOSFET devices. Thus, transistors 129, 130, 131, 132 each have an open state (e.g., an open circuit to prevent current flow) and a closed state (e.g.,a closed circuit to allow current flow). It is contemplated that each transistor described above and herein includes a respective source terminal (e.g., contact, electrode) 134A, a drain terminal 134B, and a gate terminal 134C. For simplicity, only one transistor is designated as including terminals 134A, 134B, 134C; however, it is understood that each of the transistors in piezo driver 100 is intended to include the above-mentioned terminals, as well as respective source / drain regions and gates.

[0013] Furthermore, while these exemplary source and drain contacts are shown in a particular arrangement, it should be appreciated that the source and drain regions of the respective transistor are interchangeable during operation of the piezo driver 100.

[0014] The voltage converter 128 is configured to supply electrical charge to the piezoelectric component 102 (e.g., increase the absolute voltage value across it, e.g., drive the piezoelectric component 102) via either the passive energy storage component 122 or the passive energy component 123 during a first operating state, and is configured to supply electrical charge to the respective passive energy storage component 122 or the passive energy component 123 via the piezoelectric component 102 during a second operating state (e.g., increase the absolute voltage value across it or recharge it). Each of the gate terminals 134C of the respective transistors 129, 130, 131, 132 is electrically connected to the control module 110. Thus, the control module 110 is configured to cause each of the transistors 129, 130, 131, 132 to selectively transition from the open state to the closed state, or vice versa.For example, during a first operating state, the control module 110 causes the transistors 129, 132 to be in the closed state and the transistors 130, 131 to be in the open state. In this operating state, the transistors 129, 132 and the inductor 109 form the voltage converter 128, which enables the transfer of charge between the piezo component 102 and the capacitor 122. In another example, during a second operating state, the control module 110 causes the transistors 130, 131 to be in the closed state and the transistors 129, 132 to be in the open state. In this operating state, the transistors 130, 131 and the inductor 109 form the voltage converter 128, which enables the transfer of charge between the piezo component 102 and the capacitor 123.

[0015] As described above, the control module 110 is configured to determine an operating state of the driver 100 by comparing the input signal and the measured voltage signal. For example, based on the comparison of the input signal and the measured voltage signal, the control module 110 may determine that a positive voltage should be generated across the piezo component 102 (e.g., in a first operating state). In this state, the control module 110 causes the transistors 129, 132 to be in a switching state (e.g., the module 110 generates a signal that causes the respective transistors to be in the switching state or that causes the respective transistors to transition from a first state to a second state) and causes the transistors 130, 131 to be in the open state (e.g., the module 110 generates a signal that causes the respective transistors to be in the open state).Thus, terminal 118 is electrically connected to voltage converter 128 to enable the transfer of charge from passive energy storage component 122 to piezo component 102 via voltage converter 128 until a steady state is reached. Therefore, the voltage converter is configured to initiate charge transfer from passive energy storage component 122 to piezo component 102. In this state, voltage converter 128 operates as a buck converter to initiate a buildup of positive voltage across piezo component 102.

[0016] The control module 110 may also determine (via the comparison described above) that a positive voltage across the piezoelectric component 102 should be reduced (e.g., in a second operating state). In this state, the control module 110 causes the transistors 129, 132 to be in the switching state (e.g., the module 110 generates a signal that causes the respective transistors to be in the switching state) and causes the transistors 130, 131 to be in the open state (e.g., the module 110 generates a signal that causes the respective transistors to be in the open state). The positive terminal 106 is electrically connected to the voltage converter 128 to enable the transfer of charge from the piezoelectric component 122 to the passive energy storage component 102 via the voltage converter 128 until a steady state is reached (e.g., the voltage converter operates as a boost converter).Therefore, the voltage converter 128 is configured to initiate the charge transfer from the piezo component to the passive energy storage component 122. Thus, the passive energy storage component 122 can be at least partially recharged via the electrical charge from the piezo component 102 (ie, the charge is reused).

[0017] The control module 110 may also determine (via the comparison described above) that a larger negative voltage (i.e., a more negative voltage) should be generated across the piezoelectric component 102 (e.g., in a third operating state). In this state, the control module 110 causes the transistors 130, 131 to be in the switching state (e.g., the module 110 generates a signal that causes the respective transistors to be in the switching state) and causes the transistors 129, 132 to be in the open state (e.g., the module 110 generates a signal that causes the respective transistors to be in the open state).

[0018] Thus, terminal 108 is electrically connected to voltage converter 128 to enable the transfer of charge from passive energy storage component 123 to piezoelectric component 102 via voltage converter 128 until a steady state is reached. Charge transfer occurs because the voltage across passive energy storage component 122 is higher (in absolute terms) than the voltage across piezoelectric component 102. In this state, voltage converter 128 operates as a buck converter to cause a negative voltage buildup across piezoelectric component 102.

[0019] The control module 110 may also determine (via the comparison described above) that a negative voltage across the piezoelectric component 102 should be reduced (e.g., in a fourth operating state). In this state, the control module 110 causes the transistors 130, 131 to be in the switching state (e.g., the module 110 generates a signal that causes the respective transistors to be in the switching state) and causes the transistors 129, 132 to be in the open state (e.g., the module 110 generates a signal that causes the respective transistors to be in the open state). Thus, the terminal 108 is electrically connected to the voltage converter 128 to enable the transfer of charge from the piezoelectric component 102 to the passive energy storage component 123 via the voltage converter 128 until a steady state is reached (e.g., the voltage converter operates as a boost converter).Therefore, the voltage converter 128 is configured to initiate the charge transfer from the piezo component to the passive energy storage component 123. Thus, the passive energy storage component 123 can be at least partially recharged via the electrical charge from the piezo component 102 (i.e., the charge is reused). Example procedure

[0020] Fig. 2 illustrates a method 200 for at least partially recharging an energy storage device via a piezo device in a piezo driver according to an embodiment of the present disclosure. The method includes generating a first output voltage for the first passive energy storage device 122, 123 and a second output voltage for the second passive energy storage device 122, 123 by the dual output charge pump 114 such that the first output voltage and the second output voltage are greater in absolute value than an input voltage supplied to the dual output charge pump 114.The first passive energy storage component 122, 123 is configured to store an electrical charge such that a voltage across the first passive energy storage component 122, 123 is approximately equal to the first output voltage, and the second passive energy storage component 122, 123 is configured to store an electrical charge such that a voltage across the second passive energy storage component 122, 123 is approximately equal to the second output voltage. As shown in FIG. Fig. 2, a determination is also made as to whether a voltage across a piezo component should be increased (block 202). As described above, the control module 110 is configured to determine a second operating state of the piezo driver 100 by again comparing an input signal with a signal representing the voltage across the piezo component 102. More specifically, in another embodiment, the control module 110 is configured to determine whether the voltage across the piezo component 102 should be increased (i.e., the piezo component 102 should be driven).

[0021] If it is determined that the voltage across the piezo device should be increased to drive the piezo device, a control signal is generated to cause one or more switches to transition to a desired state to allow charge transfer from the passive energy storage device to the passive energy storage device (block 204). In one embodiment, the control module 110 is configured to generate control signals (e.g., voltage values ​​or signals) to control the operation of the transistors 129, 130, 131, 132 (e.g., transitioning from a switching state to a closed state or vice versa). For example, depending on the operating state, as described in more detail above, the control module 110 may cause the transistors 129, 132 to transition to the switching state and the switches 130, 131 to transition to the open state, or vice versa.In this example, electrical charge is transferred from the passive storage device 122 to the piezo device 102 via the voltage converter 128 to increase the absolute voltage across the piezo device 102, which drives the piezo device 102. In another example, depending on the operating state, as described in more detail above, the control module 110 can cause the transistors 130, 131 to transition to the switched state and the switches 129, 132 to transition to the open state, or vice versa. In this example, electrical charge is transferred from the passive storage device 123 to the piezo device 102 via the voltage converter 128 to increase the absolute voltage across the piezo device 102, which drives the piezo device 102.

[0022] As in Fig.2, a determination is made as to whether a voltage across a piezo device should be decreased (block 206). As described above, the control module 110 is configured to determine a first operating state of the piezo driver 100 by comparing an input signal with a signal representative of the voltage across the piezo device 102. More specifically, in one embodiment, the control module 110 is configured to determine whether the voltage across the piezo device 102 should be decreased or reduced. For example, the voltage across the piezo device 102 may be decreased to return the piezo device 102 to its original state (e.g., non-driven state).

[0023] If it is determined that the voltage across the piezo device should be increased, a control signal is generated to cause one or more switches to transition to a desired state to allow charge transfer from the piezo device to a passive energy storage device (block 208). In one embodiment, the control module 110 is configured to generate control signals (e.g., voltage values ​​or signals) to control the operation of the transistors 129, 130, 131, 132 (e.g., transition from a switching state to an open state or vice versa). Thus, the desired arrangement may be the same arrangement as the arrangement described at block 204. For example, depending on the operating state, as described in more detail above, the control module 110 may cause the transistors 129, 132 to transition to the switching state and the transistors 130, 131 to transition to the open state, or vice versa.In this example, electrical charge is transferred from the piezoelectric component 102 to the passive energy storage component 122 to at least partially recharge the passive energy storage component 122 via the voltage converter 128, which may enable reuse of the electrical charge during the next operating state (e.g., reuse of the electrical charge to drive the piezoelectric component 102). In another example, depending on the operating state, as described in more detail above, the control module 110 may cause the transistors 130, 131 to transition to the closed state and the transistors 129, 132 to transition to the open state, or vice versa.In this example, electrical charge is transferred from the piezoelectric component 102 to the passive energy storage component 123 to at least partially recharge the passive energy storage component 123 via the voltage converter 128, which may enable reuse of the electrical charge during the next operating state (e.g., reuse of the electrical charge to drive the piezoelectric component 102). Concluding remark

[0024] Although the subject matter of the disclosure is described in language specific to structural features and / or method acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features and acts described above. Rather, the specific features and acts described above are disclosed as exemplary forms for practicing the claims. As used herein, the term "about" is intended to mean "approximately and / or exactly" with respect to the specified value or range.

Claims

[1] Piezo driver (100), comprising: a first passive energy storage component (122, 123) and a second passive energy storage component (122, 123), wherein the first passive energy storage component (122, 123) and the second passive energy storage component (122, 123) are configured to store electrical charge; a voltage converter (128) configured for electrical connection between a piezo component (102) and the first passive energy storage component (122, 123) and the second passive energy storage component (122, 123), wherein the voltage converter (128) is configured to supply electrical charge from the first passive energy storage component (122, 123) to the piezo component (102) during a first operating state and to supply electrical charge from the piezo component (102) to the first passive energy storage component (122, 123) during a second operating state, and the voltage converter (128) is configured to supply electrical charge from the second passive energy storage component (122, 123) to the piezo component (102) during a third operating state and to supply electrical charge from the piezo component (102) to the second passive energy storage component during a fourth operating state (122, 123) to deliver; and a dual output charge pump (114) electrically connected to the first passive energy storage component (122, 123) and the second passive energy storage component (122, 123), wherein the dual output charge pump (114) is configured to generate a first output voltage and a second output voltage that are greater in absolute value than an input voltage supplied to the dual output charge pump (114), wherein the first passive energy storage component (122, 123) is configured to store an electrical charge such that a voltage across the first passive energy storage component (122, 123) is approximately equal to the first output voltage, and the second passive energy storage component (122, 123) is configured to store an electrical charge such that a voltage across the second passive energy storage component (122, 123) is approximately equal to the second output voltage. [2] The piezo driver (100) of claim 1, wherein at least one of the first passive energy storage component (122, 123) and the second passive energy storage component (122, 123) comprises a capacitor. [3] The piezo driver (100) of claim 1, further comprising a plurality of transistors (129, 130, 131, 132) and a passive energy component (109), wherein each of the plurality of transistors (129, 130, 131, 132) is connected in series with the passive energy component (109), the passive energy component (109) is connected in series with the piezo component (102), and each of the plurality of transistors (129, 130, 131, 132) has an open state and a closed state. [4] The piezo driver (100) of claim 3, further comprising a control module (110) electrically connected to each of the plurality of transistors (129, 130, 131, 132), the control module (110) being configured to cause each of the plurality of transistors (129, 130, 131, 132) to change between the open state and the closed state to cause at least two of the plurality of transistors (129, 130, 131, 132) and the passive energy component (109) to form the voltage converter (128). [5] The piezo driver (100) of claim 4, further comprising a feedback device (104) configured for electrical connection in parallel with the piezo device (102) and electrically connected to the control module (110), the feedback device (104) configured to measure a voltage value across the piezo device (102) and provide a signal representing the voltage value to the control module (110), the control module (110) configured to switch each of the plurality of transistors (129, 130, 131, 132) between the open state and the closed state based on the signal representing the voltage value. [6] The piezo driver (100) of claim 3, wherein at least one of the plurality of transistors (129, 130, 131, 132) comprises a metal oxide semiconductor field effect transistor (MOSFET). [7] The piezo driver (100) of claim 3, wherein at least one of the plurality of transistors (129, 130, 131, 132) comprises an n-type MOSFET device. [8] Piezo driver (100), comprising: a piezo component (102); a first passive energy storage component (122, 123) and a second passive energy storage component (122, 123), wherein the first passive energy storage component (122, 123) and the second passive energy storage component (122, 123) are configured to store electrical charge; a voltage converter (128) electrically connected between the piezo component (102) and the first passive energy storage component (122, 123) and the second passive energy storage component (122, 123), wherein the voltage converter (128) is configured to supply electrical charge from the first passive energy storage component (122, 123) to the piezo component (102) during a first operating state and to supply electrical charge from the piezo component (102) to the first passive energy storage component (122, 123) during a second operating state, and the voltage converter (128) is configured to supply electrical charge from the second passive energy storage component (122, 123) to the piezo component (102) during a third operating state and to supply electrical charge from the piezo component (102) to the second passive energy storage component (122, 123) during a fourth operating state. 123); and a dual output charge pump (114) electrically connected to the first passive energy storage component (122, 123) and the second passive energy storage component (122, 123), wherein the dual output charge pump (114) is configured to generate a first output voltage and a second output voltage that are greater in absolute value than an input voltage supplied to the dual output charge pump (114), wherein the first passive energy storage component (122, 123) is configured to store an electrical charge such that a voltage across the first passive energy storage component (122, 123) is approximately equal to the first output voltage, and the second passive energy storage component (122, 123) is configured to store an electrical charge such that a voltage across the second passive energy storage component (122, 123) is approximately equal to the second output voltage. [9] The piezo driver (100) of claim 8, further comprising a plurality of transistors (129, 130, 131, 132) and an inductor (109), wherein each of the plurality of transistors (129, 130, 131, 132) is connected in series with the inductor (109), the inductor (109) is connected in series with the piezo component (102), and each of the plurality of transistors (129, 130, 131, 132) has an open state and a closed state. [10] The piezo driver (100) of claim 9, further comprising a control module (110) electrically connected to each of the plurality of transistors (129, 130, 131, 132), the control module (110) being configured to cause each of the plurality of transistors (129, 130, 131, 132) to change between the open state and the switching state to cause at least two of the plurality of transistors (129, 130, 131, 132) and the inductor (109) to form the voltage converter (128). [11] The piezo driver (100) of claim 10, further comprising a feedback device (104) electrically connected in parallel with the piezo device (102) and electrically connected to the control module (110), the feedback device (104) configured to measure a voltage value across the piezo device (102) and provide a signal representing the voltage value to the control module (110), the control module (110) configured to switch each of the plurality of transistors (129, 130, 131, 132) between the open state and the closed state based on the signal representing the voltage value. [12] The piezo driver (100) of claim 9, wherein at least one of the plurality of transistors (129, 130, 131, 132) comprises a metal oxide semiconductor field effect transistor (MOSFET). [13] The piezo driver (100) of claim 9, wherein at least one of the first passive energy storage component (122, 123) and the second passive energy storage component (122, 123) comprises a capacitor. [14] Method comprising: generating a first output voltage for a first passive energy storage component (122, 123) and a second output voltage for a second passive energy storage component (122, 123) by a dual-output charge pump (114), such that the first output voltage and the second output voltage are greater in absolute value than an input voltage supplied to the dual-output charge pump (114), wherein the first passive energy storage component (122, 123) is configured to store an electrical charge such that a voltage across the first passive energy storage component (122, 123) is approximately equal to the first output voltage, and the second passive energy storage component (122, 123) is configured to store an electrical charge such that a voltage across the second passive energy storage component (122, 123) is approximately equal to the second output voltage; determining whether a voltage across the piezo component (102) should be increased; generating a control signal to cause one or more transistors (129, 130, 131, 132) to transition to another desired state to enable transfer of electrical charge from the at least one of the first passive energy storage component (122, 123) and the second passive energy storage component (122, 123) to the piezo component (102) when the voltage across the piezo component (102) is to be increased, determining whether a voltage across a piezo component (102) should be reduced; and generating a control signal to cause one or more transistors (129, 130, 131, 132) to transition to a desired state to enable transfer of electrical charge from the piezoelectric component (102) to at least one of the first passive energy storage component (122, 123) and the second passive energy storage component (122, 123) when the voltage across the piezoelectric component (102) is to be reduced. [15] The method of claim 14, wherein the one or more transistors (129, 130, 131, 132) comprise metal oxide semiconductor field effect transistors (MOSFETs). [16] The method of claim 15, wherein the one or more switches comprise n-type MOSFETs. [17] The method of claim 14, wherein at least one of the first passive energy storage component (122, 123) and the second passive energy storage component (122, 123) comprises a capacitor. [18] The method of claim 14, wherein determining whether to reduce a voltage across the piezoelectric component (102) includes comparing an input signal with a signal representative of the voltage across the piezoelectric component (102), wherein the signal representative of the voltage across the piezoelectric component (102) is measured by a feedback component (104).

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