Voltage modulation circuit and driving device

Abstract

The application relates to a voltage modulation circuit and a driving device. The voltage modulation circuit comprises a driving control circuit configured to output a driving control signal according to a control instruction; an output circuit configured to generate a corresponding driving output voltage according to the driving control signal, the driving control signal being used for configuring the duty ratio and frequency of the driving output voltage; a front-stage circuit configured to generate and output a first pulse signal, the control instruction comprising the first pulse signal; and a feedback modulation circuit configured to generate a corresponding second pulse signal according to the driving output voltage and the first pulse signal, the control instruction comprising the second pulse signal. The feedback modulation circuit can adjust the phase difference between the first pulse signal and the second pulse signal according to the actual duty ratio variation of the driving output voltage, change the conduction time of the driving output voltage in each cycle, and finally realize the optimization of the output voltage ripple of the output circuit.

Description

Technical Field

[0001] This application belongs to the field of power supply circuit technology, and in particular relates to a voltage modulation circuit and a driving device. Background Technology

[0002] Currently, traditional switching power supplies are widely used due to their high efficiency, wide adjustable load voltage range, low loss, small size, and light weight. However, during use, the stable DC load voltage is often accompanied by AC components, which constitute the output voltage ripple. Ripple can shorten the lifespan of electrical appliances or cause noise, so when designing a system, it is essential to control the output ripple within an acceptable range.

[0003] When the load connected to the switching power supply changes, it affects the actual output voltage to the load, leading to increased output ripple. Summary of the Invention

[0004] The purpose of this application is to provide a voltage modulation circuit and a driving device, which aims to solve the problem of increased output ripple when the load changes in traditional switching power supplies.

[0005] A first aspect of this application provides a voltage modulation circuit, comprising: a drive control circuit configured to output a drive control signal according to a control command; an output circuit connected to the drive control circuit and configured to generate a corresponding drive output voltage according to the drive control signal, wherein the drive control signal is used to configure the duty cycle and frequency of the drive output voltage; a pre-stage circuit connected to the drive control circuit and configured to generate and output a first pulse signal, wherein the control command includes the first pulse signal; and a feedback modulation circuit connected to both the drive control circuit and the output circuit and configured to generate a corresponding second pulse signal according to the drive output voltage and the first pulse signal, wherein the control command includes the second pulse signal; wherein the phase difference between the first pulse signal and the second pulse signal is used to adjust the on-time of the drive output voltage in each cycle.

[0006] In one embodiment, the feedback modulation circuit includes a feedback circuit and a pulse modulation circuit. The feedback circuit is configured to generate a feedback voltage based on the duty cycle of the drive high output voltage, and the pulse modulation circuit is configured to generate and output a second pulse signal based on the feedback voltage and the first pulse signal.

[0007] In one embodiment, the feedback circuit includes a changeover switch, a filter resistor, and a filter capacitor; a first terminal of the changeover switch is connected to a standard conversion voltage terminal, a controlled terminal of the changeover switch is connected to the output circuit, a second terminal of the changeover switch is connected to a first terminal of the filter resistor, a second terminal of the filter resistor is connected to a first terminal of the filter capacitor and the modulation module, and a second terminal of the filter capacitor is grounded; the standard conversion voltage terminal is used to output a fixed maximum conversion voltage, and the changeover switch is configured to turn on or off according to the drive output voltage to generate the feedback voltage at the first terminal of the filter capacitor.

[0008] In one embodiment, the pulse modulation circuit includes a modulation module and a comparison module, wherein the modulation module is configured to adjust the phase of the second pulse output by the comparison module according to the feedback voltage.

[0009] In one embodiment, the modulation module includes a first voltage divider resistor and a second voltage divider resistor; a first end of the first voltage divider resistor is connected to the feedback circuit, a second end of the first voltage divider resistor is grounded through the second voltage divider resistor, and the connection point of the first voltage divider resistor and the second voltage divider resistor is used to output the modulation voltage, which is used as a reference voltage to be output to the comparison module.

[0010] In one embodiment, the comparison module includes an operational comparator, an energy storage switch, and an energy storage capacitor. The first terminal of the energy storage switch is connected to a current source, the second terminal of the energy storage switch is connected to the first terminal of the energy storage capacitor, the controlled terminal of the energy storage switch is connected to the drive control circuit, the second terminal of the energy storage capacitor is grounded, the first terminal of the energy storage capacitor is also connected to the inverting input terminal of the operational comparator, the non-inverting input terminal of the operational comparator is connected to the modulation module to acquire the modulation voltage, the output terminal of the comparator is used to output the second pulse signal, and the output terminal of the comparator is connected to the drive control circuit. The current source is used to charge the energy storage capacitor, generating a voltage at the first terminal of the energy storage capacitor. The drive control circuit is configured to control the energy storage switch to turn on according to the first pulse signal and to control the energy storage switch to turn off according to the second pulse signal. The operational comparator is configured to output a pulse of the second pulse signal and release the voltage at the inverting input terminal whenever the voltage at the inverting input terminal reaches the voltage at the non-inverting input terminal.

[0011] In one embodiment, the modulation module includes an adjustment transistor; the comparison module includes an operational comparator, an energy storage switch, and an energy storage capacitor; the first terminal of the energy storage switch is connected to a current source, the second terminal of the energy storage switch is connected to the first terminal of the energy storage capacitor, the controlled terminal of the energy storage switch is connected to the drive control circuit, the second terminal of the energy storage capacitor is grounded, the first terminal of the energy storage capacitor is also connected to the inverting input terminal of the operational comparator, the non-inverting input terminal of the operational comparator is connected to a reference voltage terminal, and the output terminal of the comparator is connected to the drive control circuit; the current source is used to charge the energy storage capacitor, generating a voltage at the first terminal of the energy storage capacitor; the drive control circuit is configured... The system is configured to control the energy storage switch to turn on according to the first pulse signal and control the energy storage switch to turn off according to the second pulse signal; the operational comparator is configured to output a pulse of the second pulse signal and release the voltage of the inverting input terminal whenever the voltage of the inverting input terminal reaches the voltage of the non-inverting input terminal; the first conducting terminal of the regulating transistor is connected to the first terminal of the energy storage capacitor, the controlled terminal of the regulating transistor is connected to the feedback circuit, the second conducting terminal of the regulating transistor is grounded, and the regulating transistor is configured to shunt the current output by the current source according to the feedback voltage to change the growth rate of the voltage on the energy storage capacitor.

[0012] In one embodiment, the drive control circuit includes a control module and a drive module connected to the control module. The control module is connected to the pre-amplifier circuit and the pulse modulation circuit. The control module is configured to control the drive module to output a corresponding drive control signal according to the phase difference.

[0013] In one embodiment, the output circuit includes an LC conversion circuit, a first switch, and a second switch. The first conducting terminal of the first switch is connected to a drive power supply terminal, the controlled terminal of the first switch is connected to the drive control circuit, the second conducting terminal of the first switch is connected to the first conducting terminal of the second switch, the controlled terminal of the second switch is connected to the drive control circuit, and the second conducting terminal of the second switch is grounded. The first and second switches are configured to be turned on or off according to the drive control signal to generate a corresponding drive output voltage at the second conducting terminal of the first switch. The input terminal of the LC conversion circuit is connected to the second conducting terminal of the first switch, and the LC conversion circuit generates a load voltage at its output terminal based on the drive output voltage.

[0014] A second aspect of this application provides a driving device, including: a voltage modulation circuit as described above; and a power input circuit connected to the voltage modulation circuit for supplying power to the voltage modulation circuit.

[0015] The beneficial effects of this application embodiment compared with the prior art are as follows: the above-mentioned feedback modulation circuit can adjust the phase difference between the first pulse signal and the second pulse signal according to the actual duty cycle change of the drive output voltage, thereby affecting the PWM (Pulse width modulation) voltage regulation of the drive output voltage, changing the conduction time of the drive output voltage in each cycle, and finally optimizing the output voltage ripple of the output circuit, so as to reduce the output voltage ripple of the output circuit while ensuring the power supply of the load. Attached Figure Description

[0016] Figure 1 A schematic block diagram of the voltage modulation circuit provided in the first embodiment of this application;

[0017] Figure 2 A circuit diagram of the voltage modulation circuit provided in the first embodiment of this application;

[0018] Figure 3 A circuit diagram of the feedback circuit and comparison module provided in the first embodiment of this application;

[0019] Figure 4 This is an example circuit schematic diagram of the feedback circuit and comparison module provided in the second embodiment of this application.

[0020] The above figures illustrate the following: 100, drive control circuit; 110, control module; 120, drive module; 200, output circuit; 210, LC conversion circuit; 300, pre-amplifier circuit; 400, feedback modulation circuit; 410, feedback circuit; 420, pulse modulation circuit; 421, modulation module; 422, comparator module; 500, load. Detailed Implementation

[0021] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0022] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0023] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0024] Figure 1 A schematic block diagram of the voltage modulation circuit provided in the first embodiment of this application is shown, and is described in detail below:

[0025] like Figure 1 , Figure 2 As shown, a voltage modulation circuit includes a drive control circuit 100, an output circuit 200, a pre-amplifier circuit 300, and a feedback modulation circuit 400. The drive control circuit 100 is configured to output a drive control signal according to a control command. The output circuit 200 is connected to the drive control circuit 100 and is configured to generate a corresponding drive output voltage SW based on the drive control signal. The drive control signal is used to configure the duty cycle and frequency of the drive output voltage SW. The pre-amplifier circuit 300 is connected to the drive control circuit 100 and is configured to generate and output a first pulse signal. The feedback modulation circuit 400 is connected to both the drive control circuit 100 and the output circuit 200 and is configured to generate a corresponding second pulse signal based on the drive output voltage SW and the first pulse signal. The control command includes both the first pulse signal and the second pulse signal.

[0026] It should be noted that the phase difference between the first and second pulse signals changes the frequency of the driving output voltage SW, thereby altering the on-time and off-time of the driving output voltage SW. For example, when the phase difference decreases, the frequency of the driving output voltage SW increases (the time of a single cycle decreases), meaning both the on-time and off-time decrease simultaneously. Similarly, when the phase difference increases, both the on-time and off-time of the driving output voltage SW increase simultaneously. Within one voltage cycle, the on-time is the high-level time, and the off-time is the low-level time. The ratio of the on-time to the total time of one cycle is the duty cycle.

[0027] Specifically, the feedback modulation circuit 400 can output a second pulse signal based on the driving output voltage SW that changes due to the load 500 and the first pulse signal. When the second pulse signal is transmitted to the driving control circuit 100, the driving control circuit 100 can output a corresponding driving control signal based on the phase difference between the first pulse signal and the second pulse signal, thereby changing the conduction time of the driving output voltage SW accordingly, so as to optimize the output voltage ripple.

[0028] like Figure 2As shown, in this embodiment, the output circuit 200 includes an LC conversion circuit 210, a first switch Q1, and a second switch Q2. The first conducting terminal of the first switch Q1 is connected to the drive power supply terminal VIN, the controlled terminal of the first switch Q1 is connected to the drive control circuit 100, the second conducting terminal of the first switch Q1 is connected to the first conducting terminal of the second switch Q2, the controlled terminal of the second switch Q2 is connected to the drive control circuit 100, and the second conducting terminal of the second switch Q2 is grounded. The first switch Q1 and the second switch Q2 can be turned on or off according to the drive control signal to generate a corresponding drive output voltage SW at the second conducting terminal of the first switch Q1. The input terminal of the LC conversion circuit 210 is connected to the second conducting terminal of the first switch Q1, and the output terminal of the LC conversion circuit 210 is connected to the load 500. The LC conversion circuit 210 is used to generate a DC load voltage according to the drive output voltage SW. Both the first switch Q1 and the second switch Q2 can be NMOS transistors, with their first conducting terminal being the drain of the NMOS transistor, their second conducting terminal being the source of the NMOS transistor, and their controlled terminal being the gate of the NMOS transistor.

[0029] It should be noted that since the second conducting terminal of the first switching transistor Q1 also needs to be connected to the load 500 through the LC conversion circuit 210, when the load 500 changes, the LC conversion circuit 210 will affect the drive output voltage SW. For example, when the load 500 is reduced, the off time (low level time) of the drive output voltage SW will increase, changing the actual duty cycle of the drive output voltage SW.

[0030] like Figure 2 As shown, in this embodiment, the LC conversion circuit 210 includes an output inductor L1 and an output capacitor C3. The first end of the output inductor L1 is connected to the second conducting end of the first switching transistor Q1, and the second end of the output inductor L1 is connected to the first end of the output capacitor C3. The second end of the output capacitor C3 is grounded to generate a corresponding load voltage at the second end of the output inductor L1 according to the driving output voltage SW. The first end of the output inductor L1 is the input terminal of the LC conversion circuit 210, and the second end of the output inductor L1 is the output terminal of the LC conversion circuit 210.

[0031] In this embodiment, the output voltage ripple formula is: ,in △Vout represents the output voltage ripple, V ESR For the output capacitor C3, the output voltage ripple is V. CrippleThe output voltage ripple is calculated for charging and discharging the output capacitor C3. Vin is the voltage value at the drive power supply terminal VIN, Vout is the load voltage, L is the inductance value of the output inductor L1, C is the capacitance value of the output capacitor C3, ESR is the series parasitic resistance of the output capacitor C3, and Ton is the on-time of the drive output voltage SW in each cycle. According to the output voltage ripple formula, the on-time of the drive output voltage SW is positively correlated with the magnitude of the output voltage ripple. When other parameters are difficult to adjust, the output voltage ripple can be reduced by decreasing the on-time.

[0032] like Figure 2 As shown, in this embodiment, the drive control circuit 100 includes a control module 110 and a drive module 120 connected to the control module 110. The control module 110 is connected to the front-end circuit 300 and the feedback modulation circuit 400. The control module 110 is configured to control the drive module 120 to output a corresponding drive control signal based on the phase difference between the first pulse signal and the second pulse signal. Both the control module 110 and the drive module 120 can be a microcontroller, a microprocessor, or a chip.

[0033] like Figure 3 As shown, in this embodiment, the feedback modulation circuit 400 includes a feedback circuit 410 and a pulse modulation circuit 420. The feedback circuit 410 is configured to generate a feedback voltage according to the duty cycle of the drive output voltage SW, and the pulse modulation circuit 420 is configured to generate and output a second pulse signal according to the feedback voltage and the first pulse signal.

[0034] Specifically, the feedback circuit 410 includes a changeover switch S1, a filter resistor R1, and a filter capacitor C1. The first terminal of the changeover switch S1 is connected to the standard conversion voltage terminal MAX, the controlled terminal of the changeover switch S1 is connected to the second conducting terminal of the first switching transistor Q1, the second terminal of the changeover switch S1 is connected to the first terminal of the filter resistor R1, the second terminal of the filter resistor R1 is connected to the first terminal of the filter capacitor C1 and the modulation module 421, and the second terminal of the filter capacitor C1 is grounded. The standard conversion voltage terminal MAX is used to output a fixed maximum conversion voltage. The changeover switch S1 is configured to turn on or off according to the drive output voltage SW to generate a feedback voltage at the first terminal of the filter capacitor C1. The changeover switch S1 can be an NMOS transistor. When the drive output voltage SW is high, the changeover switch S1 is on; when the drive output voltage SW is low, the changeover switch S1 is off. The first terminal of the changeover switch S1 is the drain of the NMOS transistor, the second terminal of the changeover switch S1 is the source of the NMOS transistor, and the controlled terminal of the changeover switch S1 is the gate of the NMOS transistor.

[0035] It should be noted that in this embodiment, the larger the duty cycle of the driving output voltage SW (the off-time of the driving output voltage SW decreases while the on-time of the driving output voltage SW remains unchanged), the larger the ratio of the on-time to the off-time of the switching switch S1, and the larger the generated feedback voltage. Similarly, the smaller the duty cycle of the driving output voltage SW (the off-time of the driving output voltage SW increases while the on-time of the driving output voltage SW remains unchanged), the smaller the ratio of the on-time to the off-time of the switching switch S1, and the smaller the generated feedback voltage. The feedback circuit 410 realizes the generation of a corresponding feedback voltage according to the magnitude of the duty cycle of the driving output voltage SW.

[0036] like Figure 3 As shown, in this embodiment, the pulse modulation circuit 420 includes a modulation module 421 and a comparison module 422. The modulation module 421 is configured to adjust the phase of the second pulse output by the comparison module 422 according to the feedback voltage. The modulation module 421 includes a first voltage divider resistor R2 and a second voltage divider resistor R3. The first end of the first voltage divider resistor R2 is connected to the feedback circuit 410, and the second end of the first voltage divider resistor R2 is grounded through the second voltage divider resistor R3. The connection point of the first voltage divider resistor R2 and the second voltage divider resistor R3 is used to output a modulation voltage. The modulation module 421 is used to further divide the feedback voltage to reduce the feedback voltage to an appropriate modulation voltage.

[0037] like Figure 3 As shown, in this embodiment, the modulated voltage is used as a reference voltage output to the comparison module 422. Specifically, the comparison module 422 includes an operational comparator U1, an energy storage switch S2, and an energy storage capacitor C2. The first terminal of the energy storage switch S2 is connected to the current source I1, the second terminal of the energy storage switch S2 is connected to the first terminal of the energy storage capacitor C2, the controlled terminal of the energy storage switch S2 is connected to the control module 110 of the drive control circuit 100, the second terminal of the energy storage capacitor C2 is grounded, the first terminal of the energy storage capacitor C2 is also connected to the inverting input terminal of the operational comparator U1, the non-inverting input terminal of the operational comparator U1 is connected to the modulation module 421 to obtain the modulated voltage and use it as a reference voltage, the output terminal of the operational comparator U1 is used to output a second pulse signal, and the output terminal of the operational comparator U1 is connected to the control module 110 of the drive control circuit 100. The current source I1 can charge the energy storage capacitor C2, generating a voltage on the energy storage capacitor C2. The control module 110 is configured to control the energy storage switch S2 to turn on whenever a first pulse signal is received, and to control the energy storage switch S2 to turn off whenever a second pulse signal is received, wherein the first pulse signal is a high-level pulse and the second pulse signal is a low-level pulse.

[0038] Among them, the energy storage switch S2 can be a field-effect transistor.

[0039] The operational comparator U1 is configured such that whenever the voltage at the inverting input reaches the voltage at the non-inverting input, the operational comparator outputs a low-level pulse (second pulse signal) and releases the voltage at the inverting input, causing the voltage on the energy storage capacitor C2 to become 0.

[0040] It should be noted that, under the control of the control module 110, the energy storage switch S2 is turned on according to the first pulse signal, causing the current source I1 to charge the energy storage capacitor C2. The voltage at the first terminal of the energy storage capacitor C2 begins to increase steadily. When the voltage at the inverting input terminal reaches the voltage at the positive input terminal, the operational comparator U1 outputs a low-level pulse, thereby generating a second pulse signal. With a constant voltage growth rate, the magnitude of the reference voltage determines the time from when the control module 110 receives the high-level pulse of the first pulse signal (energy storage switch S2 is turned on) to when the operational comparator U1 outputs a low-level pulse. This determines the time difference between each pulse of the first and second pulse signals, thus achieving the effect of changing the phase difference between the first and second pulse signals according to the modulation voltage. The phase difference between the first and second pulse signals then corresponds to the control of the drive control circuit 100, which outputs a corresponding drive control signal.

[0041] In the actual operation of the voltage modulation circuit, when the load decreases from 500, the off-time of the drive output voltage SW increases (the duty cycle decreases), and the feedback voltage output by the feedback circuit 410 also decreases. Since the modulation voltage and the feedback voltage are positively correlated, when the modulation voltage is used as the reference voltage of the operational comparator U1, under the condition that the charging rate of the energy storage capacitor C2 remains unchanged, the voltage at the inverting input terminal of the operational comparator U1 can reach the voltage at the non-inverting input terminal faster. The phase difference between the second pulse signal and the first pulse signal output by the operational comparator U1 decreases, and finally the drive control circuit 100 outputs the corresponding drive control signal, so that the conduction time of the drive output voltage SW in each cycle is reduced, thereby optimizing the output voltage ripple of the output circuit 200.

[0042] Figure 4 An example circuit schematic diagram of the feedback circuit 410 and the comparison module 422 provided in the second embodiment of this application is shown below in detail:

[0043] Unlike the first embodiment, in this embodiment, the modulation module 421 includes an adjustment transistor Q3; the comparison module 422 includes an operational comparator U1, an energy storage switch S2, and an energy storage capacitor C2; the first terminal of the energy storage switch S2 is connected to the current source I1, the second terminal of the energy storage switch S2 is connected to the first terminal of the energy storage capacitor C2, the controlled terminal of the energy storage switch S2 is connected to the control module 110 of the drive control circuit 100, the second terminal of the energy storage capacitor C2 is grounded, the first terminal of the energy storage capacitor C2 is also connected to the inverting input terminal of the operational comparator U1, the non-inverting input terminal of the operational comparator U1 is connected to the reference voltage terminal Vref for obtaining the reference voltage, the output terminal of the operational comparator U1 is used to output a second pulse signal, and the output terminal of the operational comparator U1 is connected to the control module 110 of the drive control circuit 100. The first conducting terminal of the adjustment transistor Q3 is connected to the first terminal of the energy storage capacitor C2, the controlled terminal of the adjustment transistor Q3 is connected to the feedback circuit 410, and the second conducting terminal of the adjustment transistor Q3 is grounded.

[0044] It should be noted that the regulating transistor Q3 is configured to shunt the current output from the current source I1 according to the magnitude of the feedback voltage, thereby changing the voltage growth rate of the energy storage capacitor C2. This, in turn, adjusts the time it takes for the voltage at the inverting input of the operational comparator U1 to reach the voltage at the non-inverting input, i.e., changing the phase difference between the second pulse signal and the first pulse signal output by the operational comparator U1. Specifically, the smaller the feedback voltage, the smaller the current shunt by the regulating transistor Q3, the greater the voltage growth rate of the energy storage capacitor C2, resulting in a shorter time for the voltage at the inverting input to reach the voltage at the non-inverting input, and a smaller phase difference.

[0045] The third embodiment of this application provides a driving device, including: a power input circuit and a voltage modulation circuit as described in any of the above embodiments; the power input circuit is provided with a current source I1, a reference voltage terminal Vref, a standard conversion voltage terminal MAX and a driving power supply terminal VIN, and the power input circuit can be connected to the control module 110, the driving module 120, the output circuit 200, the comparison module 422 and the feedback circuit 410 respectively, for supplying power to the control module 110, the driving module 120, the output circuit 200, the comparison module 422 and the feedback circuit 410 respectively.

[0046] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is merely an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The specific working process of the units and modules in the above system can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0047] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0048] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A voltage modulation circuit, characterized by, include: The drive control circuit is configured to output drive control signals according to control commands; An output circuit, connected to the drive control circuit, is configured to generate a corresponding drive output voltage according to the drive control signal, wherein the drive control signal is used to configure the duty cycle and frequency of the drive output voltage. A pre-stage circuit, connected to the drive control circuit, is configured to generate and output a first pulse signal, and the control command includes the first pulse signal; A feedback modulation circuit, connected to the drive control circuit and the output circuit respectively, is configured to generate a corresponding second pulse signal based on the drive output voltage and the first pulse signal, and the control command includes the second pulse signal; The phase difference between the second pulse signal and the first pulse signal is positively correlated with the duty cycle of the drive output voltage; The phase difference between the first pulse signal and the second pulse signal is used to adjust the on-time of the drive output voltage in each cycle.

2. The voltage modulation circuit of claim 1, wherein, The feedback modulation circuit includes a feedback circuit and a pulse modulation circuit. The feedback circuit is configured to generate a feedback voltage based on the duty cycle of the drive output voltage, and the pulse modulation circuit is configured to generate and output a second pulse signal based on the feedback voltage and the first pulse signal.

3. The voltage modulation circuit of claim 2, wherein, The feedback circuit includes a changeover switch, a filter resistor, and a filter capacitor; the first terminal of the changeover switch is connected to the standard conversion voltage terminal, the controlled terminal of the changeover switch is connected to the output circuit, the second terminal of the changeover switch is connected to the first terminal of the filter resistor, the second terminal of the filter resistor is connected to the first terminal of the filter capacitor and the pulse modulation circuit, and the second terminal of the filter capacitor is grounded. The standard conversion voltage terminal is used to output a fixed maximum conversion voltage, and the conversion switch is configured to turn on or off according to the drive output voltage to generate the feedback voltage at the first terminal of the filter capacitor.

4. The voltage modulation circuit of claim 2, wherein, The pulse modulation circuit includes a modulation module and a comparison module. The modulation module is configured to adjust the phase of the second pulse output by the comparison module according to the feedback voltage.

5. The voltage modulation circuit of claim 4, wherein, The modulation module includes a first voltage divider resistor and a second voltage divider resistor; the first end of the first voltage divider resistor is connected to the feedback circuit, the second end of the first voltage divider resistor is grounded through the second voltage divider resistor, and the connection point of the first voltage divider resistor and the second voltage divider resistor is used to output a modulation voltage, which is used as a reference voltage to be output to the comparison module.

6. The voltage modulation circuit of claim 5, wherein, The comparison module includes an operational comparator, an energy storage switch, and an energy storage capacitor. The first terminal of the energy storage switch is connected to a current source, the second terminal of the energy storage switch is connected to the first terminal of the energy storage capacitor, the controlled terminal of the energy storage switch is connected to the drive control circuit, the second terminal of the energy storage capacitor is grounded, the first terminal of the energy storage capacitor is also connected to the inverting input terminal of the operational comparator, the non-inverting input terminal of the operational comparator is connected to the modulation module to acquire the modulation voltage, the output terminal of the comparator is used to output the second pulse signal, and the output terminal of the comparator is connected to the drive control circuit. The current source is used to charge the energy storage capacitor, generating a voltage at the first terminal of the energy storage capacitor. The drive control circuit is configured to control the energy storage switch to turn on according to the first pulse signal and to control the energy storage switch to turn off according to the second pulse signal. The operational comparator is configured such that whenever the voltage at the inverting input reaches the voltage at the non-inverting input, the operational comparator outputs a pulse of the second pulse signal and releases the voltage at the inverting input.

7. The voltage modulation circuit of claim 4, wherein, The modulation module includes an adjustment tube; the comparison module includes an operational comparator, an energy storage switch, and an energy storage capacitor; the first terminal of the energy storage switch is connected to a current source, the second terminal of the energy storage switch is connected to the first terminal of the energy storage capacitor, the controlled terminal of the energy storage switch is connected to the drive control circuit, the second terminal of the energy storage capacitor is grounded, the first terminal of the energy storage capacitor is also connected to the inverting input terminal of the operational comparator, the non-inverting input terminal of the operational comparator is connected to a reference voltage terminal, and the output terminal of the comparator is connected to the drive control circuit; the current source is used to charge the energy storage capacitor and generate a voltage at the first terminal of the energy storage capacitor; the drive control circuit is configured to control the energy storage switch to turn on according to the first pulse signal and control the energy storage switch to turn off according to the second pulse signal; The operational comparator is configured such that whenever the voltage at the inverting input reaches the voltage at the non-inverting input, the operational comparator outputs a pulse of the second pulse signal and releases the voltage at the inverting input. The first conducting terminal of the regulating tube is connected to the first terminal of the energy storage capacitor, the controlled terminal of the regulating tube is connected to the feedback circuit, the second conducting terminal of the regulating tube is grounded, and the regulating tube is configured to shunt the current output by the current source according to the feedback voltage in order to change the growth rate of the voltage on the energy storage capacitor.

8. The voltage modulation circuit of claim 2, wherein, The drive control circuit includes a control module and a drive module connected to the control module. The control module is connected to the pre-amplifier circuit and the pulse modulation circuit. The control module is configured to control the drive module to output the corresponding drive control signal according to the phase difference.

9. The voltage modulation circuit of any one of claims 1-8, wherein, The output circuit includes an LC conversion circuit, a first switching transistor, and a second switching transistor; the first conducting terminal of the first switching transistor is connected to the driving power supply terminal, the controlled terminal of the first switching transistor is connected to the driving control circuit, the second conducting terminal of the first switching transistor is connected to the first conducting terminal of the second switching transistor, the controlled terminal of the second switching transistor is connected to the driving control circuit, and the second conducting terminal of the second switching transistor is grounded. The first and second switching transistors are configured to be turned on or off according to the drive control signal to generate a corresponding drive output voltage at the second conducting terminal of the first switching transistor. The input terminal of the LC conversion circuit is connected to the second conducting terminal of the first switching transistor, and the LC conversion circuit is used to generate a load voltage at the output terminal of the LC conversion circuit according to the drive output voltage.

10. A driving apparatus characterized by comprising: include: The voltage modulation circuit as described in any one of claims 1-9; as well as A power input circuit is provided, which is connected to the voltage modulation circuit and is used to supply power to the voltage modulation circuit.

Images