CN116707302A - Piezoelectric ceramic differential charge pump driving circuit and control method - Google Patents

Abstract

The invention discloses a piezoelectric ceramic differential charge pump driving circuit and a control method, which relate to the field of piezoelectric ceramic precise driving control, wherein two ends of a direct current voltage stabilizing source are respectively connected with a single-pole double-throw switch to provide switchable positive and negative reference voltages, two ends of a charge pump capacitor are respectively connected with the single-pole double-throw switch to switch between the direct current voltage stabilizing source and two high-voltage operational amplifiers, two ends of the charge pump capacitor are charged from the direct current voltage stabilizing source, and equal and opposite charges are respectively injected into the two piezoelectric ceramics connected with the high-voltage operational amplifiers, so that the differential charge pump driving and control are realized. The invention simplifies the charge driving circuit of the piezoelectric bimorph, provides equal differential charges for two piezoelectric ceramics, and greatly improves the control precision of the bending displacement of the piezoelectric bimorph by utilizing the charge driving technology.

Description

Piezoelectric ceramic differential charge pump driving circuit and control method

Technical Field

The invention relates to the field of piezoelectric ceramic precise driving control, in particular to a piezoelectric ceramic differential charge pump driving circuit and a control method.

Background

In the field of precise drive control, the piezoelectric ceramic driver has the advantages of high displacement resolution, large driving force, high response speed and the like, is a preferred scheme of nanoscale precise drive, and is widely applied to application occasions such as semiconductor manufacture, optical measurement, biomedical treatment and the like which relate to nanoscale positioning operation. The piezoelectric ceramic driver utilizes the inverse piezoelectric effect, and the output displacement of the piezoelectric ceramic driver is formed by the strain in the material caused by the driving voltage applied to the surface electrode, but the nonlinear relationship such as hysteresis and creep exists between the driving voltage and the output displacement of the piezoelectric ceramic driver, so that the displacement control precision of the piezoelectric ceramic driver is severely restricted.

The piezoelectric bimorph is the most common piezoelectric ceramic driver, utilizes differential strain of upper layer piezoelectric plate and lower layer piezoelectric plate (the upper layer piezoelectric plate is elongated, the lower layer piezoelectric plate is shortened), and utilizes strain gradient to form bending deformation, and has the characteristics of simple structure, large output displacement and the like. Because the piezoelectric bimorph at least comprises two piezoelectric sheets, and the applied driving voltages are different, the upper layer piezoelectric sheet and the lower layer piezoelectric sheet need two high-voltage amplifiers to be driven respectively, and the control difficulty and the system cost are high. In order to reduce the complexity of the driving circuit, patent No. US5233256 proposes to implement differential driving of a single high voltage amplifier by optimizing the electrode connection, but the control accuracy of this method is limited due to the large non-linear error of the voltage driving. In order to avoid nonlinearity of the piezoelectric driving, patent No. CN110518829B proposes a piezoelectric bimorph charge driving circuit, which uses a charge amplifying circuit to replace a voltage amplifying circuit, so as to improve nonlinearity of the piezoelectric driving, but the method has strict ratio requirements on circuit parameters, and is equivalent to a common voltage amplifying circuit under low frequency condition, and the practical effect of the circuit is limited. Therefore, there is a need to further combine the features of piezoelectric bimorphs and charge driving circuits to provide more efficient differential charge driving circuits and control methods.

Disclosure of Invention

The invention aims to overcome the defects of the prior art, and provides a piezoelectric ceramic differential charge pump driving circuit and a control method, which are used for solving the technical problems of complex driving circuit, poor control precision and the like of a piezoelectric bimorph in the prior art.

The invention is realized by the following technical scheme:

a piezoelectric ceramic differential charge pump driving circuit is characterized in that: the high-voltage power supply comprises a direct-current voltage stabilizing source E, a single-pole double-throw switch S1, a single-pole double-throw switch S2, a single-pole double-throw switch S3, a single-pole double-throw switch S4, a charge pump capacitor Ci, piezoelectric ceramics Cp1, piezoelectric ceramics Cp2, a high-voltage operational amplifier A1 and a high-voltage operational amplifier A2;

the fixed ports of the single-pole double-throw switches S1 and S2 are respectively connected with two ends of the direct-current voltage stabilizing source E, the switching ports of the single-pole double-throw switches S1 and S2 are respectively connected with two ends of the charge pump capacitor Ci in a cross manner, and positive and negative reference voltages are respectively provided for the charge pump capacitor Ci through synchronous switching of the single-pole double-throw switches S1 and S2;

the fixed ports of the single-pole double-throw switches S3 and S4 are respectively connected with two ends of the charge pump capacitor Ci, one ends of the switching ports of the single-pole double-throw switches S3 and S4 are respectively connected with two ends of the direct-current voltage stabilizing source E, the other ends of the single-pole double-throw switches are respectively connected with the opposite ends of the high-voltage operational amplifiers A1 and A2, and the charge pump capacitor Ci is respectively charged and discharged through synchronous switching of the single-pole double-throw switches S3 and S4;

the positive electrode of the piezoelectric ceramic Cp1 is connected with the reverse phase end of the high-voltage operational amplifier A1, and the negative electrode is connected with the output end of the high-voltage operational amplifier A1; the positive electrode of the piezoelectric ceramic Cp2 is connected with the reverse phase end of the high-voltage operational amplifier A2, and the negative electrode is connected with the output end of the high-voltage operational amplifier A2; and the same-phase terminals of the high-voltage operational amplifiers A1 and A2 are grounded.

In order to achieve the above purpose, the present invention also provides a piezoelectric ceramic differential charge pump control method, which comprises the following steps:

step one, the single-pole double-throw switches S1 and S2 synchronously switch the connection with the charge pump capacitor Ci, and a direct-current voltage stabilizing source E provides positive reference voltage +E for the charge pump capacitor Ci;

step two, the single-pole double-throw switches S3 and S4 are synchronously switched and connected with a direct-current voltage stabilizing source E, the direct-current voltage stabilizing source E charges two ends of a charge pump capacitor Ci, positive charges +Δq and negative charges- Δq are respectively injected, and the charge quantity Δq is expressed as:

ΔQ＝E·Ci (1)；

step three, the synchronous switching of the single-pole double-throw switches S3 and S4 is connected with the opposite phase ends of the high-voltage operational amplifiers A1 and A2, the charge pump capacitor Ci discharges, positive charges +DeltaQ stored at one end are injected into the piezoelectric ceramic Cp1, and negative charges-DeltaQ stored at the other end are injected into the piezoelectric ceramic Cp2;

step four, repeating the step two and the step three, wherein the single-pole double-throw switches S3 and S4 are switched back and forth between the direct-current voltage stabilizing source E and the high-voltage operational amplifiers A1 and A2, charge and discharge cyclic operation is carried out at two ends of the charge pump capacitor Ci, positive charges +DeltaQ are continuously injected into the piezoelectric ceramic Cp1, the total charge quantity of the piezoelectric ceramic Cp1 is gradually increased, the output displacement is increased, negative charges-DeltaQ are continuously injected into the piezoelectric ceramic Cp2, the total charge quantity of the piezoelectric ceramic Cp2 is gradually reduced, and the output displacement is reduced;

step five, the single-pole double-throw switches S1 and S2 synchronously switch the connection with the charge pump capacitor Ci, and a direct-current voltage stabilizing source E provides negative reference voltage-E for the charge pump capacitor Ci;

step six, the single-pole double-throw switches S3 and S4 are synchronously switched and connected with a direct-current voltage-stabilizing source E, and the direct-current voltage-stabilizing source E charges two ends of a charge pump capacitor Ci and respectively injects negative charge-delta Q and positive charge +delta Q;

step seven, the single-pole double-throw switches S3 and S4 are synchronously switched and connected with the opposite phase ends of the high-voltage operational amplifiers A1 and A2, the charge pump capacitor Ci discharges, negative charge-delta Q stored at one end is injected into the piezoelectric ceramic Cp1, and positive charge +delta Q stored at the other end is injected into the piezoelectric ceramic Cp2;

step eight, repeating the step six and the step seven, wherein the single-pole double-throw switches S3 and S4 are switched back and forth between the direct-current voltage stabilizing source E and the high-voltage operational amplifiers A1 and A2, charge and discharge cyclic operation is carried out at two ends of the charge pump capacitor Ci, negative charges-delta Q are continuously injected into the piezoelectric ceramic Cp1, the total charge quantity of the piezoelectric ceramic Cp1 is gradually reduced, the output displacement is reduced, positive charges +delta Q are continuously injected into the piezoelectric ceramic Cp2, the total charge quantity of the piezoelectric ceramic Cp2 is gradually increased, and the output displacement is increased;

and step nine, the single-pole double-throw switches S1 and S2 synchronously switch the connection with the charge pump capacitor Ci, and the direct-current voltage stabilizing source E provides positive reference voltage +E for the charge pump capacitor Ci.

Compared with the prior art, the invention has the following advantages:

(1) Both ends of the charge pump capacitor Ci are respectively connected with the opposite ends of the high-voltage operational amplifiers A1 and A2 and are in a virtual ground state, so that the charge pump capacitor Ci is not required to be connected with a common ground. By matching a single direct-current voltage stabilizing source E with single-pole double-throw switches S1 and S2, positive and negative reference voltages can be provided for a charge pump capacitor Ci, and the fact that positive charges and negative charges are injected into a single piezoelectric ceramic Cp1 or Cp2 is equal in charge quantity delta Q is guaranteed.

(2) The single-pole double-throw switches S3 and S4 are synchronously switched and connected with the opposite ends of the high-voltage operational amplifiers A1 and A2, current flows out from the output end of the high-voltage operational amplifier A1, flows into the output end of the high-voltage operational amplifier A2 through the piezoelectric ceramic Cp1, the charge pump capacitor Ci and the piezoelectric ceramic Cp2, positive charges injected by the piezoelectric ceramic Cp1 and negative charges injected by the piezoelectric ceramic Cp2 keep equal charge quantity delta Q, the total charge quantity of the piezoelectric ceramic Cp1 is increased by delta Q, the total charge quantity of the piezoelectric ceramic Cp2 is reduced by delta Q, and differential charge pump driving is realized.

Drawings

FIG. 1 is a schematic diagram of a piezoelectric ceramic differential charge pump drive circuit according to the present invention;

FIG. 2 is a flow chart of a method for controlling a piezoelectric ceramic differential charge pump according to the present invention;

FIG. 3 is a schematic diagram of a portion of signals during the driving control of the piezoelectric ceramic differential charge pump according to the present invention.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

As shown in fig. 1, a piezoelectric ceramic differential charge pump driving circuit comprises a direct-current voltage stabilizing source E, a single-pole double-throw switch S1, a single-pole double-throw switch S2, a single-pole double-throw switch S3, a single-pole double-throw switch S4, a charge pump capacitor Ci, a piezoelectric ceramic Cp1, a piezoelectric ceramic Cp2, a high-voltage operational amplifier A1 and a high-voltage operational amplifier A2;

the fixed ports of the single-pole double-throw switches S1 and S2 are respectively connected with two ends of the direct-current voltage stabilizing source E, the switching ports of the single-pole double-throw switches S1 and S2 are respectively connected with two ends of the charge pump capacitor Ci in a cross manner, and positive and negative reference voltages are respectively provided for the charge pump capacitor Ci through synchronous switching of the single-pole double-throw switches S1 and S2;

the fixed ports of the single-pole double-throw switches S3 and S4 are respectively connected with two ends of the charge pump capacitor Ci, one ends of the switching ports of the single-pole double-throw switches S3 and S4 are respectively connected with two ends of the direct-current voltage stabilizing source E, the other ends of the single-pole double-throw switches are respectively connected with the opposite ends of the high-voltage operational amplifiers A1 and A2, and the charge pump capacitor Ci is respectively charged and discharged through synchronous switching of the single-pole double-throw switches S3 and S4;

the positive electrode of the piezoelectric ceramic Cp1 is connected with the reverse phase end of the high-voltage operational amplifier A1, and the negative electrode is connected with the output end of the high-voltage operational amplifier A1; the positive electrode of the piezoelectric ceramic Cp2 is connected with the reverse phase end of the high-voltage operational amplifier A2, and the negative electrode is connected with the output end of the high-voltage operational amplifier A2; and the same-phase terminals of the high-voltage operational amplifiers A1 and A2 are grounded.

As shown in fig. 1-3, based on the piezoelectric ceramic differential charge pump driving circuit, the piezoelectric ceramic differential charge pump control method according to the present invention includes the following steps:

in step S01, at time t0, the single-pole double-throw switches S1 and S2 apply a high level, synchronously switch up the connection with the charge pump capacitor Ci, the dc voltage stabilizing source E provides a positive reference voltage +e for the charge pump capacitor Ci, the single-pole double-throw switches S3 and S4 apply a low level, synchronously switch right and connect with the inverting terminals of the high-voltage operational amplifiers A1 and A2, and the initial charge amounts of the piezoelectric ceramics Cp1 and Cp2 are zero.

In step S02, at time t1, the single-pole double-throw switches S3 and S4 apply a high level, and are synchronously switched to the left and connected to a dc voltage-stabilizing source E, where the dc voltage-stabilizing source E charges two ends of the charge pump capacitor Ci, positive charges +Δq are injected at the upper end, negative charges- Δq are injected at the lower end, and the charge quantity Δq is expressed as:

ΔQ＝E·Ci (1)；

in step S03, at time t2, the single-pole double-throw switches S3 and S4 apply a low level, switch to the right synchronously, connect with the opposite ends of the high-voltage operational amplifiers A1 and A2, discharge the charge pump capacitor Ci, inject positive charge +Δq stored in the upper end into the piezoelectric ceramic Cp1, and inject negative charge- Δq stored in the lower end into the piezoelectric ceramic Cp2;

in step S04, repeating step S02 and steps S03 to t3, where the single-pole double-throw switches S3 and S4 switch back and forth between the dc voltage stabilizing source E and the high-voltage operational amplifiers A1 and A2, the charge pump capacitor Ci performs charge and discharge cycle operation at both ends, positive charges +Δq are continuously injected into the piezoelectric ceramic Cp1, the total charge amount of the piezoelectric ceramic Cp1 is gradually increased, the output displacement is increased, negative charges- Δq are continuously injected into the piezoelectric ceramic Cp2, the total charge amount of the piezoelectric ceramic Cp2 is gradually reduced, and the output displacement is reduced;

in step S05, at time t3, the single-pole double-throw switches S1 and S2 apply a low level, synchronously switch down the connection with the charge pump capacitor Ci, and the dc voltage stabilizing source E provides a negative reference voltage-E for the charge pump capacitor Ci; the single-pole double-throw switches S3 and S4 apply low level and synchronously switch to the right to be connected with the opposite ends of the high-voltage operational amplifiers A1 and A2, the total charge amount of the piezoelectric ceramic Cp1 is +6DeltaQ, and the total charge amount of the piezoelectric ceramic Cp2 is-6DeltaQ;

in step S06, at time t4, the single-pole double-throw switches S3 and S4 apply a high level, and synchronously switch to the left to connect with the dc voltage-stabilizing source E, where the dc voltage-stabilizing source E charges two ends of the charge pump capacitor Ci, the upper end is injected with negative charge- Δq, and the lower end is injected with positive charge +Δq;

in step S07, at time t5, the single-pole double-throw switches S3 and S4 apply a low level, switch to the right synchronously, connect with the opposite ends of the high-voltage operational amplifiers A1 and A2, discharge the charge pump capacitor Ci, inject the negative charge- Δq stored in the upper end into the piezoelectric ceramic Cp1, and inject the positive charge +Δq stored in the lower end into the piezoelectric ceramic Cp2;

in step S08, the steps S06 and S07 to t6 are repeated, the single-pole double-throw switches S3 and S4 switch back and forth between the dc voltage stabilizing source E and the high-voltage operational amplifiers A1 and A2, the charge pump capacitor Ci performs charge and discharge cyclic operation on both ends, the negative charge- Δq is continuously injected into the piezoelectric ceramic Cp1, the total charge amount of the piezoelectric ceramic Cp1 is gradually reduced, the output displacement is reduced, the positive charge +Δq is continuously injected into the piezoelectric ceramic Cp2, the total charge amount of the piezoelectric ceramic Cp2 is gradually increased, and the output displacement is increased.

In step S09, at time t6, the single-pole double-throw switches S1 and S2 apply a high level, and synchronously switch up the connection with the charge pump capacitor Ci, where the dc voltage stabilizing source E provides a positive reference voltage +e for the charge pump capacitor Ci; the single-pole double-throw switches S3 and S4 apply low level, synchronously switch to the right and are connected with the opposite phase ends of the high-voltage operational amplifiers A1 and A2, and the total charge quantity of the piezoelectric ceramics Cp1 and Cp2 is zero.

By controlling the switching frequency and the number of times of the steps S04 and S08, the total charge amount of the piezoelectric ceramics Cp1 and Cp2 can be accurately controlled to change according to a set curve, and the accurate bending displacement output of the piezoelectric bimorph is realized.

Claims (2)

1. A piezoelectric ceramic differential charge pump driving circuit is characterized in that: the high-voltage power supply comprises a direct-current voltage stabilizing source E, a single-pole double-throw switch S1, a single-pole double-throw switch S2, a single-pole double-throw switch S3, a single-pole double-throw switch S4, a charge pump capacitor Ci, piezoelectric ceramics Cp1, piezoelectric ceramics Cp2, a high-voltage operational amplifier A1 and a high-voltage operational amplifier A2;

the fixed ports of the single-pole double-throw switches S1 and S2 are respectively connected with two ends of the direct-current voltage stabilizing source E, the switching ports of the single-pole double-throw switches S1 and S2 are respectively connected with two ends of the charge pump capacitor Ci in a cross manner, and positive and negative reference voltages are respectively provided for the charge pump capacitor Ci through synchronous switching of the single-pole double-throw switches S1 and S2;

the fixed ports of the single-pole double-throw switches S3 and S4 are respectively connected with two ends of the charge pump capacitor Ci, one ends of the switching ports of the single-pole double-throw switches S3 and S4 are respectively connected with two ends of the direct-current voltage stabilizing source E, the other ends of the single-pole double-throw switches are respectively connected with the opposite ends of the high-voltage operational amplifiers A1 and A2, and the charge pump capacitor Ci is respectively charged and discharged through synchronous switching of the single-pole double-throw switches S3 and S4;

the positive electrode of the piezoelectric ceramic Cp1 is connected with the reverse phase end of the high-voltage operational amplifier A1, and the negative electrode is connected with the output end of the high-voltage operational amplifier A1; the positive electrode of the piezoelectric ceramic Cp2 is connected with the reverse phase end of the high-voltage operational amplifier A2, and the negative electrode is connected with the output end of the high-voltage operational amplifier A2; and the same-phase terminals of the high-voltage operational amplifiers A1 and A2 are grounded.

2. A piezoelectric ceramic differential charge pump control method is characterized in that: a piezoelectric ceramic differential charge pump driving circuit according to claim 1, comprising the steps of:

step one, the single-pole double-throw switches S1 and S2 synchronously switch the connection with the charge pump capacitor Ci, and a direct-current voltage stabilizing source E provides positive reference voltage +E for the charge pump capacitor Ci;

step two, the single-pole double-throw switches S3 and S4 are synchronously switched and connected with a direct-current voltage stabilizing source E, the direct-current voltage stabilizing source E charges two ends of a charge pump capacitor Ci, positive charges +Δq and negative charges- Δq are respectively injected, and Δq is expressed as:

ΔQ＝E·Ci (1)；

step three, the synchronous switching of the single-pole double-throw switches S3 and S4 is connected with the opposite phase ends of the high-voltage operational amplifiers A1 and A2, the charge pump capacitor Ci discharges, positive charges +DeltaQ stored at one end are injected into the piezoelectric ceramic Cp1, and negative charges-DeltaQ stored at the other end are injected into the piezoelectric ceramic Cp2;

step four, repeating the step two and the step three, wherein the single-pole double-throw switches S3 and S4 are switched back and forth between the direct-current voltage stabilizing source E and the high-voltage operational amplifiers A1 and A2, charge and discharge cyclic operation is carried out at two ends of the charge pump capacitor Ci, positive charges +DeltaQ are continuously injected into the piezoelectric ceramic Cp1, the total charge quantity of the piezoelectric ceramic Cp1 is gradually increased, the output displacement is increased, negative charges-DeltaQ are continuously injected into the piezoelectric ceramic Cp2, the total charge quantity of the piezoelectric ceramic Cp2 is gradually reduced, and the output displacement is reduced;

step five, the single-pole double-throw switches S1 and S2 synchronously switch the connection with the charge pump capacitor Ci, and a direct-current voltage stabilizing source E provides negative reference voltage-E for the charge pump capacitor Ci;

step six, the single-pole double-throw switches S3 and S4 are synchronously switched and connected with a direct-current voltage-stabilizing source E, and the direct-current voltage-stabilizing source E charges two ends of a charge pump capacitor Ci and respectively injects negative charge-delta Q and positive charge +delta Q;

step seven, the single-pole double-throw switches S3 and S4 are synchronously switched and connected with the opposite phase ends of the high-voltage operational amplifiers A1 and A2, the charge pump capacitor Ci discharges, negative charge-delta Q stored at one end is injected into the piezoelectric ceramic Cp1, and positive charge +delta Q stored at the other end is injected into the piezoelectric ceramic Cp2;

step eight, repeating the step six and the step seven, wherein the single-pole double-throw switches S3 and S4 are switched back and forth between the direct-current voltage stabilizing source E and the high-voltage operational amplifiers A1 and A2, charge and discharge cyclic operation is carried out at two ends of the charge pump capacitor Ci, negative charges-delta Q are continuously injected into the piezoelectric ceramic Cp1, the total charge quantity of the piezoelectric ceramic Cp1 is gradually reduced, the output displacement is reduced, positive charges +delta Q are continuously injected into the piezoelectric ceramic Cp2, the total charge quantity of the piezoelectric ceramic Cp2 is gradually increased, and the output displacement is increased;

and step nine, the single-pole double-throw switches S1 and S2 synchronously switch the connection with the charge pump capacitor Ci, and the direct-current voltage stabilizing source E provides positive reference voltage +E for the charge pump capacitor Ci.