A new power amplifier power supply circuit for ultrasonic drivers

Abstract

The present invention belongs to the field of ultrasonic drive technology. The present invention provides a new power amplifier power supply circuit for an ultrasonic driver, including: an amplifier circuit connected to an AC voltage source, used to receive an AC reference signal, and output a power supply voltage required by a load based on the input AC reference signal; an auxiliary circuit connected to the amplifier circuit and the load, used to adjust the voltage value of the power supply voltage required by the load according to the state of the load, so as to adjust the current power consumption to the preset power consumption. In the present invention, by adjusting the voltage value of the power supply Vs+ or Vs‑ in real time according to the load size, the power consumption of the power amplifier chip is reduced by using a variable voltage power supply.

Description

Technical Field

[0001] The invention relates to the technical field of ultrasonic drive, and in particular to a novel power amplifier power supply circuit for an ultrasonic driver. Background Art

[0002] In the ultrasonic driver structure, the general power amplifier module is powered by a positive and negative voltage power supply. Since the load impedance of the transducer varies greatly in actual operation, in order to ensure that the output power meets the standard under heavy load, the voltage values ​​of the positive and negative power supply voltages of the power amplifier are usually designed according to the corresponding output voltage under heavy load. However, such a design will result in a lower output voltage when the load is light and the output power is low. The voltage difference between the high voltage of the positive and negative power supply voltages of the power amplifier and the lower output voltage is absorbed by the power amplifier module, resulting in excessive power consumption of the output of the power amplifier module.

[0003] To facilitate understanding of the disadvantages of fixed voltage power supply, actual values ​​are used for illustration below.

[0004] For example, in Figure 1 In the circuit, assuming that the output voltage of the power amplifier module driving a heavy load is 20sinωt volts, then the output voltage of the power amplifier chip when driving a light load of one-tenth is 2sinωt volts. Usually, Vs+ will be designed according to the output voltage required for heavy loads, slightly higher than 20V (for example: 24V), and Vs- will generally be slightly lower than -20V (for example: -24V). Since the vibration amplitude of the transducer is determined by the current amplitude, that is, regardless of the load impedance, the output current amplitude will be controlled according to a fixed target current. Assuming the total output current is 5sin(ωt+φ) amperes, then Figure 1 In the circuit, the output current of U1 is 2.5sin(ωt+φ). Then the power consumption of U1 is roughly equal to 24*5 / π-2*5 / 4*cosφ when lightly loaded, and roughly equal to 24*5 / π-20*5 / 4*cosφ when heavily loaded. Obviously, the power consumption of U1 is much higher when lightly loaded than when heavily loaded, because the Vs+ and Vs- voltages are mostly absorbed by the power amplifier module when lightly loaded. Summary of the invention

[0005] The purpose of the present invention is to provide a new power amplifier power supply method for an ultrasonic driver, which can solve the above problems. If the voltages of Vs+ and Vs- can be reduced when the load is light, the power consumption of the power amplifier module can be reduced. For example, in the above example, the voltages of Vs+ and Vs- when the load is light are changed to 6V and -6V respectively, then the power consumption of U1 when the load is light is approximately equal to 6*5 / π-2*5 / 4*cosφ.

[0006] In the above formula, ω is the frequency of the AC signal output to the transducer, and φ is the phase difference between the current and the voltage.

[0007] However, since the load changes in real time, it is difficult to synchronize the responses of the two power modules and it is difficult to adjust the voltage values ​​of the two power modules simultaneously and accurately.

[0008] Therefore, the technical solution provided by the present invention is as follows:

[0009] In some embodiments, the present invention provides a novel power amplifier power supply circuit for an ultrasonic driver, comprising:

[0010] an amplifier circuit connected to an AC voltage source, configured to receive an AC reference signal and output a power supply voltage required by a load based on the input AC reference signal;

[0011] The auxiliary circuit is connected to the amplifier circuit and the load, and is used to adjust the voltage value of the forward supply voltage according to the state of the load, so as to adjust the current power consumption to the preset power consumption.

[0012] In some embodiments, the amplifier circuit includes:

[0013] The AC source module is used to receive the control signal output by the main processor and output an AC reference signal;

[0014] The amplifier module is connected to the AC source module and is used to output a supply voltage based on an input AC reference signal.

[0015] In some embodiments, the amplifier circuit further includes:

[0016] The diode module is connected to the amplifier module and the auxiliary circuit, and is used to output a positive power supply current or a negative power supply voltage to the auxiliary circuit.

[0017] In some embodiments, the AC source module includes: a first AC voltage source, a second AC voltage source, a second amplifier, and a second diode;

[0018] The first AC voltage source is used to receive a first control signal output by the main processor and output a first AC reference signal;

[0019] The second AC voltage source is used to receive a second control signal output by the main processor and output a second AC reference signal.

[0020] In some embodiments, the amplifier module includes: a first amplifier and a second amplifier;

[0021] The first amplifier is connected to the first AC voltage source and the first diode, and is used to output a supply voltage based on an input AC reference signal;

[0022] The second amplifier is connected to the second AC voltage source and the second diode, and is used to output a supply voltage based on an input AC reference signal.

[0023] In some embodiments, the diode module includes: a first diode and a second diode;

[0024] The first diode is connected to the auxiliary circuit and is used to output a forward supply current to the auxiliary circuit;

[0025] The second diode and the auxiliary circuit are used to output a forward supply current to the auxiliary circuit.

[0026] In some embodiments, the AC source module includes a first AC voltage source and a bias voltage source; the amplifier module includes a first amplifier and a second amplifier;

[0027] The first AC voltage source is connected to the bias voltage source, the first amplifier and the second amplifier, and is used to input a first AC reference signal so that the first amplifier and the second amplifier output a power supply voltage required by a load.

[0028] In some embodiments, the amplifier circuit further includes:

[0029] The first capacitor is connected to the output ends of the first amplifier and the second amplifier, and is used to filter out the DC bias signal of the forward power supply voltage.

[0030] In some embodiments, the output voltage of the bias voltage source is half of the forward supply voltage.

[0031] In some embodiments, the auxiliary circuit includes: a transformer;

[0032] The transformer is connected to the amplifier circuit and the load, and is used to amplify the forward supply voltage to match the load.

[0033] The novel power amplifier power supply circuit for an ultrasonic driver provided by the present invention has at least the following beneficial effects:

[0034] In the present invention, the voltage value of the power supply Vs+ or Vs- is adjusted in real time according to the load size, thereby realizing a variable voltage power supply mode to reduce the power consumption of the power amplifier chip. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The following will explain the preferred implementation mode in a clear and understandable manner in conjunction with the accompanying drawings, and further illustrate the above-mentioned characteristics, technical features, advantages and implementation methods of a new power amplifier power supply circuit for an ultrasonic driver.

[0036] Figure 1 is a schematic diagram of a power amplifier power supply circuit of a conventional ultrasonic driver;

[0037] Figure 2 It is a schematic diagram of a first embodiment of a novel power amplifier power supply circuit for an ultrasonic driver in the present invention;

[0038] Figure 3 It is a waveform principle diagram of the first embodiment of the present invention;

[0039] Figure 4 is a schematic diagram of a second embodiment of a novel power amplifier power supply circuit for an ultrasonic driver in the present invention;

[0040] Figure 5 It is a waveform principle diagram of the second embodiment of the present invention. DETAILED DESCRIPTION

[0041] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the specific implementation methods of the present invention will be described below with reference to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings and other implementation methods can be obtained based on these drawings without creative work.

[0042] In order to simplify the drawings, only the parts related to the present invention are schematically shown in each figure, and they do not represent the actual structure of the product. In addition, in order to simplify the drawings and facilitate understanding, in some figures, only one of the parts with the same structure or function is schematically drawn or marked. In this article, "one" not only means "only one", but also means "more than one".

[0043] Embodiment 1

[0044] In the first embodiment, the amplifier circuit includes:

[0045] The AC source module is used to receive the control signal output by the main processor and output an AC reference signal;

[0046] The amplifier module is connected to the AC source module and is used to output a power supply voltage required by the load based on an input AC reference signal.

[0047] In one embodiment, the amplifier circuit further includes:

[0048] The diode module is connected to the amplifier module and the auxiliary circuit, and is used to output a positive power supply current or a negative power supply current to the auxiliary circuit.

[0049] In one embodiment, the AC source module includes: a first AC voltage source, a second AC voltage source, a second amplifier, and a second diode;

[0050] The first AC voltage source is used to receive a first control signal output by the main processor and output a first AC reference signal;

[0051] The second AC voltage source is used to receive a second control signal output by the main processor and output a second AC reference signal.

[0052] The first amplifier is connected to the first AC voltage source and the first diode, and is used to output a supply voltage based on an input AC reference signal;

[0053] The second amplifier is connected to the second AC voltage source and the second diode, and is used to output a supply voltage based on an input AC reference signal.

[0054] The first diode is connected to the auxiliary circuit and is used to output a forward supply current to the auxiliary circuit;

[0055] The second diode and the auxiliary circuit are used to output a forward supply current to the auxiliary circuit;

[0056] The first diode and the second diode are diodes with the same direction.

[0057] For example, Figure 2 The power amplifier circuit diagram of the ultrasonic knife driver is shown. In this embodiment, transformer T1 is used to amplify the voltage output by the power amplifier chip to match the performance requirements of the transducer. T2 is a transducer device that can convert electrical energy into mechanical energy. S1 and S2 are AC control signals generated in real time by the main processor and the DA digital-to-analog conversion circuit.

[0058] in, Figure 2 U1 and U2 are power amplifier modules (for example, analog power amplifier chips such as PA05, hereinafter referred to as power amplifier modules). In fact, depending on the output power requirements, there may be only one power amplifier module or multiple power amplifier modules driven in parallel, or multiple modules may be driven in a push-pull manner. For example, the U1 and U2 modules in the circuit receive opposite S1 and S2 signals and drive T1 together.

[0059] For ease of understanding, Figure 3The typical waveform diagram corresponding to the above circuit is shown. S1 and S2 are the reference voltages of the power amplifier modules U1 and U2 respectively. They have the same amplitude and opposite directions. Therefore, after amplification by the power amplifier module, the voltages Vout1 and Vout2 output by U1 and U2 are also AC voltages with the same amplitude and opposite directions. In addition, due to the presence of diode D1, Iout1 will only be in the positive direction. Similarly, due to the presence of D2, Iout2 will also only be in the positive direction.

[0060] 1. Adjust the voltage values ​​of the power supply Vs+ and Vs- in real time according to the load size, thereby reducing the power consumption of the power amplifier module.

[0061] 2. Since the load changes in real time, it is difficult to precisely adjust the voltage values ​​of the two power supplies at the same time. It is also difficult to synchronize the responses of the two power modules.

[0062] 3. Figure 2 It is a single power supply real-time voltage reduction circuit solution that can be used on a dual voltage power supply amplifier module. Figure 3 The corresponding typical voltage and current waveforms are shown below.

[0063] 4. In this scheme, U1 outputs a voltage signal Vout1 with driving capability according to the AC reference signal S1. Since the diode D1 can only flow current in one direction, only forward current will flow out of the output end of U1, that is, positive supply voltage Vs + output current. U2 outputs a voltage signal Vout2 with driving capability according to the AC reference signal S2 (generally S1 and S2 are in opposite phases). Since the diode D2 can only flow current in one direction, only forward current will flow out of the output end of U2, that is, positive supply voltage Vs + output current.

[0064] It can be seen that in this solution, the output current of the power amplifier is provided by Vs+, so the power consumption of the power amplifier module can be reduced by adjusting the Vs+ voltage value according to the load conditions, while Vs- is fixed to a constant voltage value and only provides the power amplifier module with a static bias current for normal operation. This solution has another variant topology, that is, the polarity of diodes D1 and D2 is reversed, then Vs+ is fixed to a constant value, only providing the power amplifier module with a static bias current for normal operation, and Vs- adjusts the voltage value according to the load conditions to reduce the power consumption of the power amplifier module.

[0065] For example, Figure 2 The ultrasonic driver structure is shown. Figure 2The main processor analyzes and calculates the transducer voltage and current signals obtained by the voltage and current sampling circuit to obtain the real-time impedance value of the load, and then generates a reference signal and calculates the power supply voltage value to control the variable power supply module to adjust the output power supply voltage of the power amplifier. In this embodiment, by adjusting the voltage value of the power supply Vs+ or Vs- in real time according to the load size, the variable voltage power supply method is used to reduce the power consumption of the power amplifier chip.

[0066] Embodiment 2

[0067] In one embodiment, the AC source module includes a first AC voltage source and a bias voltage source; the amplifier module includes a first amplifier and a second amplifier;

[0068] The first AC voltage source is connected to the bias voltage source, the first amplifier and the second amplifier, and is used to input a first AC reference signal so that the first amplifier and the second amplifier output a power supply voltage required by a load.

[0069] In this embodiment, the amplifier circuit further includes:

[0070] The first capacitor is connected to the output ends of the first amplifier and the second amplifier, and is used to filter out the DC bias component of the power supply voltage required by the load.

[0071] For example, Figure 4 , 5 As shown in the figure, the positive and negative voltage power supply of the power amplifier module is changed to a single voltage power supply. Since an AC drive signal needs to be output, a bias voltage S3 needs to be added. Generally, this value is set at about half of the power supply voltage Vs+. Then, a DC blocking capacitor C1 can be used to remove the DC bias component of the output. This circuit can reduce the power amplifier loss under low load conditions by simply reducing the operating voltage of Vs+. Figure 5 The typical voltage and current waveforms corresponding to the second embodiment are shown. The supply voltage is assumed to be 48V, so the bias voltage is 24V.

[0072] In this embodiment, this value is generally set to be near half of the supply voltage Vs+. This value is only a general value and is not necessary. However, if it is set to half, the DC voltage can be maximized.

[0073] For example: if the supply voltage is A and the bias voltage is set to A / 2, then theoretically the output voltage is A / 2+A / 2*sinwt. If it is set to another value, such as A / 2+B, then theoretically only the output voltage is A / 2+B+(A / 2-|B|)*sinwt. The DC bias voltage will be filtered out by capacitor C1. Obviously, when B is zero, the output AC signal is the largest.

[0074] For example, Figure 4 The ultrasonic driver structure is shown. Figure 4 The main processor analyzes and calculates the voltage and current signals of the transducer obtained by the voltage and current sampling circuit to obtain the real-time impedance value of the load, and then generates a reference signal and calculates the power supply voltage value to control the variable power supply module to adjust the output power supply voltage of the power amplifier. In this embodiment, by adjusting the voltage value of the power supply Vs+ in real time according to the load size, the power consumption of the power amplifier chip can be reduced by using a variable voltage power supply.

[0075] In this embodiment, those skilled in the art can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned program modules is used as an example. In actual applications, the above-mentioned functions can be assigned to different program modules as needed, that is, the internal structure of the device can be divided into different program units or modules to complete all or part of the functions described above. The program modules in the embodiment can be integrated into a processing unit, or each unit can exist physically separately, or two or more units can be integrated into a processing unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software program units. In addition, the specific names of the program modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application.

[0076] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0077] Those of ordinary skill in the art will appreciate that the units of the examples described in conjunction with the embodiments disclosed herein can be implemented with electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed with hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0078] In the embodiments provided in the present application, it should be understood that the disclosed system can be implemented in other ways. Exemplarily, the embodiments described above are merely schematic. Exemplarily, the division of the modules or units is only a logical function division. There may be other division methods in actual implementation. Exemplarily, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0079] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0080] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above integrated unit may be implemented in the form of hardware or in the form of software functional units.

Claims

1. A novel power amplifier power supply circuit for an ultrasonic driver, characterized in that: include: an amplifier circuit connected to an AC voltage source, configured to receive an AC reference signal and output a power supply voltage required by a load based on the input AC reference signal; An auxiliary circuit, connected between the amplifier circuit and the load, for adjusting the voltage value of the power supply voltage according to the state of the load, so as to adjust the current power consumption to the preset power consumption; The amplifier circuit comprises: The AC source module is used to receive the control signal output by the main processor and output an AC reference signal; an amplifier module, connected to the AC source module, and configured to output a supply voltage based on an input AC reference signal; The amplifier circuit further includes: A diode module, connected between the amplifier module and the auxiliary circuit, and used for outputting a positive power supply current or a negative power supply current to the auxiliary circuit; The AC source module comprises: a first AC voltage source and a second AC voltage source; The first AC voltage source is used to receive a first control signal output by the main processor and output a first AC reference signal; The second AC voltage source is used to receive a second control signal output by the main processor and output a second AC reference signal; The diode module comprises: a first diode and a second diode; The first diode is connected to the auxiliary circuit and is used to output the forward supply current required by the load and flow into the load through the auxiliary circuit; The second diode is connected to the auxiliary circuit and is used to output the negative power supply current required by the load and flow into the load through the auxiliary circuit; The amplifier module comprises: a first amplifier and a second amplifier; The first amplifier has a first signal input terminal in- connected to the output terminal of the first AC voltage source, a second signal input terminal in+ connected to ground, an output terminal Vout1 connected to the anode of the first diode, and a cathode of the first diode connected to the input terminal of the auxiliary circuit; and is used to output a supply voltage based on an input AC reference signal; The first power supply input terminal V+ of the first amplifier is connected to the positive power supply voltage Vs+, and the second power supply input terminal V- is connected to the negative power supply voltage Vs-; The first signal input terminal in- of the second amplifier is connected to the output terminal of the second AC voltage source, the second signal input terminal in+ is grounded, the output terminal Vout2 is connected to the anode of the second diode, and the cathode of the second diode is connected to the input terminal of the auxiliary circuit; and is used to output a supply voltage based on the input AC reference signal; The first power supply input terminal V+ of the second amplifier is connected to the positive power supply voltage Vs+, and the second power supply input terminal V- is connected to the negative power supply voltage Vs-; The voltage values ​​of the positive power supply voltage Vs+ and the negative power supply voltage Vs- supplied to the first amplifier and the second amplifier are adjusted in real time according to the load size.

2. A novel power amplifier power supply circuit for an ultrasonic driver according to claim 1, characterized in that: The auxiliary circuit comprises: a transformer; The transformer is connected between the amplifier circuit and the load, and is used to amplify the supply voltage to match the load.

3. A novel power amplifier power supply circuit for an ultrasonic driver, characterized in that: include: an amplifier circuit connected to an AC voltage source, configured to receive an AC reference signal and output a power supply voltage required by a load based on the input AC reference signal; An auxiliary circuit, connected between the amplifier circuit and the load, for adjusting the voltage value of the power supply voltage according to the state of the load, so as to adjust the current power consumption to the preset power consumption; The amplifier circuit comprises: The AC source module is used to receive the control signal output by the main processor and output an AC reference signal; an amplifier module, connected to the AC source module, and configured to output a supply voltage based on an input AC reference signal; The AC source module includes a first AC voltage source and a bias voltage source; the amplifier module includes a first amplifier and a second amplifier; The first AC voltage source is connected to the bias voltage source, the first amplifier and the second amplifier, and is used to input a first AC reference signal so that the first amplifier and the second amplifier output a power supply voltage required by a load; The amplifier circuit further includes: a first capacitor connected to the output terminals of the first amplifier and the second amplifier, and used for filtering out a DC bias component of a power supply voltage; The negative electrode of the bias voltage source is grounded, and the positive electrode is connected to the first AC voltage source; The first signal input terminal in- of the first amplifier is connected to the output terminal of the first AC voltage source, the second signal input terminal in+ is grounded, the output terminal Vout1 is connected to one end of the first capacitor, and the other end of the first capacitor is connected to the input terminal of the auxiliary circuit; The first power supply input terminal V+ of the first amplifier is connected to the positive power supply voltage Vs+, and the second power supply input terminal V- is connected to the ground; The first input terminal in- of the second amplifier is connected to the output terminal of the first AC voltage source, the second input terminal in+ is grounded, the output terminal Vout1 is connected to one end of the first capacitor, and the other end of the first capacitor is connected to the input terminal of the auxiliary circuit; The first power supply input terminal V+ of the second amplifier is connected to the positive power supply voltage Vs+, and the second power supply input terminal V- is connected to the ground; The voltage value of the forward power supply voltage Vs+ supplied to the first amplifier and the second amplifier is adjusted in real time according to the load size.

4. A novel power amplifier power supply circuit for an ultrasonic driver according to claim 3, characterized in that: The output voltage of the bias voltage source is half of the forward supply voltage.

5. A novel power amplifier power supply circuit for an ultrasonic driver according to claim 3 or 4, characterized in that: The auxiliary circuit comprises: a transformer; The transformer is connected between the amplifier circuit and the load, and is used to amplify the supply voltage to match the load.

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