Bipolar output voltage conversion circuit and control method therefor

Abstract

Provided in the present disclosure are a bipolar output voltage conversion circuit and a control method therefor. The bipolar output voltage conversion circuit comprises a control circuit and a power stage circuit. The control circuit comprises: a common-mode control circuit, which is used for outputting a common-mode error signal on the basis of a positive-voltage error signal and a negative-voltage error signal; a differential-mode control circuit, which is used for outputting a differential-mode error signal on the basis of the positive-voltage error signal and the negative-voltage error signal; and a pulse width modulation logic control circuit, which is used for respectively outputting a first pulse control signal and a second pulse control signal on the basis of the common-mode error signal and the differential-mode error signal. The power stage circuit is used for controlling a current path on the basis of the first pulse control signal and the second pulse control signal, so as to modulate the positive-voltage output voltage and a negative-voltage output voltage. The bipolar output voltage conversion circuit provided in the present disclosure can effectively suppress intermodulation interference, reduce the complexity of circuit design, improve the circuit robustness, and ensure the stability and quality of an output voltage.

Description

Bipolar output voltage conversion circuit and control method thereof Technical Field

[0001] The present disclosure relates to the field of voltage conversion, and in particular to a bipolar output voltage conversion circuit and a control method thereof. Background Art

[0002] Active-Matrix Organic Light-Emitting Diode (AMOLED) display panels are widely used in portable devices such as mobile phones, bracelets, and watches due to their high display quality and small size. During use, AMOLED display panels generally require a bipolar output voltage conversion circuit including a positive voltage power supply and a negative voltage power supply to simultaneously supply power. Related technologies often use a single-inductor bipolar output (SIBO) DC-DC bipolar output voltage converter, with positive and negative voltage outputs at both ends of an inductor, as a power supply to power the AMOLED display panel.

[0003] In the process of realizing the concept disclosed herein, the inventors discovered that there are at least the following problems in the related art: the traditional SIBO DC-DC bipolar output voltage converter often adopts the ordered power distributive control (OPDC) timing linear control method, in which the positive output voltage obtains energy first and then the negative output voltage obtains energy. The modulation priority of the positive output voltage is higher than the adjustment priority of the negative output voltage, resulting in the positive output voltage and the negative output voltage interfering with each other during the modulation process, causing intermodulation interference problems, affecting the stability and quality of the voltage output voltage, and thus affecting the working stability and display quality of the AMOLED display panel.

[0004] Summary of the Invention

[0005] In view of the above problems, the present disclosure provides a bipolar output voltage conversion circuit and a control method thereof.

[0006] According to the first aspect of the present disclosure, a bipolar output voltage conversion circuit is provided. The bipolar output voltage conversion circuit includes a control circuit and a power stage circuit. The control circuit includes: a common-mode control circuit for outputting a common-mode error signal based on a received positive voltage error signal and a received negative voltage error signal, wherein the common-mode error signal is used to control the total energy input to the power stage circuit; a differential-mode control circuit for outputting a differential-mode error signal based on a received positive voltage error signal and a received negative voltage error signal, wherein the differential-mode error signal is used to control the energy allocated to the positive voltage output voltage and the negative voltage output voltage in the power stage circuit; and a pulse width modulation logic control circuit, connected to the common-mode control circuit and the differential-mode control circuit, respectively, for outputting a first pulse control signal and a second pulse control signal based on the received common-mode error signal and the received differential-mode error signal. The power stage circuit is used to control the current path based on the first pulse control signal and the second pulse control signal to modulate the positive voltage output voltage and the negative voltage output voltage.

[0007] According to an embodiment of the present disclosure, the above-mentioned control circuit also includes: a positive voltage error amplifier, which is used to output the above-mentioned positive voltage error signal based on the received above-mentioned positive voltage output voltage and positive voltage reference voltage, and the output end of the above-mentioned positive voltage error amplifier is respectively connected to the input end of the above-mentioned common-mode control circuit and the input end of the above-mentioned differential-mode control circuit; and a negative voltage error amplifier, which is used to output the above-mentioned negative voltage error signal based on the received above-mentioned negative voltage output voltage and negative voltage reference voltage, and the output end of the above-mentioned negative voltage amplifier is respectively connected to the input end of the above-mentioned common-mode control circuit and the input end of the above-mentioned differential-mode control circuit.

[0008] According to an embodiment of the present disclosure, the common-mode error signal is obtained by adding the positive pressure error signal and the negative pressure error signal; and the differential-mode error signal is obtained by subtracting the positive pressure error signal from the negative pressure error signal.

[0009] According to an embodiment of the present disclosure, the above-mentioned power stage circuit includes: a power input terminal for receiving an input voltage; an inductor module for storing and transmitting the energy of the above-mentioned input voltage; a positive voltage output terminal for outputting the above-mentioned positive voltage output voltage at one end of the above-mentioned inductor module; a negative voltage output terminal for outputting the above-mentioned negative voltage output voltage at the other end of the above-mentioned inductor module; a ground terminal; and a switch module, connected to the output terminal of the above-mentioned pulse width modulation logic control circuit, for controlling the above-mentioned current path according to the received above-mentioned first pulse control signal and the above-mentioned second pulse control signal.

[0010] According to an embodiment of the present disclosure, the current path includes: when the first pulse control signal is at a high level and the second pulse control signal is at a high level, the current in the power stage circuit is controlled by the switch module to operate in a first path, where the first path is the path of the current in the power stage circuit flowing from the power input terminal to the ground terminal;

[0011] When the first pulse control signal is at a low level and the second pulse control signal is at a low level, the current in the power stage circuit is controlled by the switch module to operate in a second path, where the second path is the path where the current in the power stage circuit flows from the negative voltage output terminal to the positive voltage output terminal;

[0012] When the first pulse control signal is at a low level and the second pulse control signal is at a high level, the current in the power stage circuit is controlled by the switch module to operate in a third path, where the third path is a path for the current in the power stage circuit to flow from the negative voltage output terminal to the ground terminal;

[0013] When the above-mentioned first pulse control signal is at a high level and the above-mentioned second pulse control signal is at a low level, the current in the above-mentioned power stage circuit is controlled by the above-mentioned switch module to operate in a fourth path, and the above-mentioned fourth path is the path of the current in the above-mentioned power stage circuit flowing from the above-mentioned power supply input end to the above-mentioned positive voltage output end.

[0014] According to an embodiment of the present disclosure, the power stage circuit is configured such that: when the differential-mode error signal is zero, the pulse width of the first pulse control signal and the pulse width of the second pulse control signal generated by the pulse-width modulation logic control circuit are the same, and the current in the power stage circuit alternately operates in the first path and the second path under the control of the switch module;

[0015] When the differential-mode error signal is greater than zero, the pulse width of the first pulse control signal generated by the pulse-width modulation logic control circuit is wider than the pulse width of the second pulse control signal, and the current in the power stage circuit alternately operates in the first path, the fourth path, and the second path under the control of the switch module;

[0016] When the differential-mode error signal is less than zero, the pulse width of the first pulse control signal generated by the pulse-width modulation logic control circuit is narrower than the pulse width of the second pulse control signal, and the current in the power stage circuit operates alternately in the first path, the third path, and the second path under the control of the switching module.

[0017] When the common-mode error signal rises, the pulse width of the first pulse control signal and the pulse width of the second pulse control signal are increased by the pulse width modulation logic control circuit, thereby increasing the working time of the current in the power stage circuit working in the first path.

[0018] When the common-mode error signal decreases, the pulse width of the first pulse control signal and the pulse width of the second pulse control signal are reduced by the pulse width modulation logic control circuit, thereby reducing the time during which the current in the power stage circuit operates in the first path.

[0019] According to an embodiment of the present disclosure, the power stage circuit further includes a positive output capacitor and a negative output capacitor, and the switch module includes a first switch, a second switch, a third switch and a fourth switch. The first end of the first switch is connected to the power input end, the second end of the first switch is connected to the first end of the inductor module, the second end of the inductor module is connected to the first end of the third switch, the second end of the third switch is connected to the first end of the positive output capacitor, the second end of the positive output capacitor is connected to the first end of the negative output capacitor, the second end of the negative output capacitor is connected to the first end of the fourth switch, the second end of the fourth switch is connected to the first end of the inductor module, the second end of the positive output capacitor and the first end of the negative output capacitor are commonly connected to the ground end, the first end of the second switch is connected to the second end of the inductor module, and the second end of the second switch is connected to the ground end.

[0020] The first switch, the second switch, the third switch, and the fourth switch are configured as follows:

[0021] When the first pulse control signal is at a high level and the second pulse control signal is at a high level, the first switch and the second switch are synchronously turned on, the third switch and the fourth switch are synchronously turned off, and the current in the power stage circuit operates in the first path;

[0022] When the first pulse control signal is at a low level and the second pulse control signal is at a low level, the first switch and the second switch are synchronously turned off, the third switch and the fourth switch are synchronously turned on, and the current in the power stage circuit operates in the second path;

[0023] When the first pulse control signal is at a low level and the second pulse control signal is at a high level, the first switch and the third switch are synchronously turned off, the second switch and the fourth switch are synchronously turned on, and the current in the power stage circuit operates in the third path;

[0024] When the first pulse control signal is at a high level and the second pulse control signal is at a low level, the first switch and the third switch are synchronously turned on, the second switch and the fourth switch are synchronously turned off, and the current in the power stage circuit operates in the fourth path.

[0025] According to an embodiment of the present disclosure, the power stage circuit further includes a conducting capacitor, and the switch module further includes a fifth switch, wherein a first end of the conducting capacitor is connected to a first end of the inductor module, a second end of the conducting capacitor is connected to a first end of the fifth switch, and a second end of the fifth switch is connected to a second end of the second switch;

[0026] The first switch, the second switch, the third switch, the fourth switch and the fifth switch are configured as follows:

[0027] When the first pulse control signal is at a high level and the second pulse control signal is at a high level, the first switch, the second switch, and the fifth switch are synchronously turned on, the third switch and the fourth switch are synchronously turned off, and the current in the power stage circuit operates in the first path;

[0028] When the first pulse control signal is at a low level and the second pulse control signal is at a low level, the first switch, the second switch, and the fifth switch are synchronously turned off, the third switch and the fourth switch are synchronously turned on, and the current in the power stage circuit operates in the second path;

[0029] When the first pulse control signal is at a low level and the second pulse control signal is at a high level, the first switch, the third switch, and the fifth switch are synchronously turned off, the second switch and the fourth switch are synchronously turned on, and the current in the power stage circuit operates in the third path;

[0030] When the first pulse control signal is at a high level and the second pulse control signal is at a low level, the first switch, the third switch and the fifth switch are synchronously turned on, the second switch and the fourth switch are synchronously turned off, and the current in the power stage circuit operates in the fourth path.

[0031] According to an embodiment of the present disclosure, the bipolar output voltage conversion circuit is a single-inductor bipolar output DC-DC bipolar output voltage converter.

[0032] A second aspect of the present disclosure provides a bipolar output voltage conversion circuit control method. The bipolar output voltage conversion circuit control method includes:

[0033] receiving a positive voltage error signal and a negative voltage error signal through a common-mode control circuit and outputting a common-mode error signal, wherein the common-mode error signal is used to control the total energy input to the power stage circuit;

[0034] receiving the positive voltage error signal and the negative voltage error signal through a differential mode control circuit and outputting a differential mode error signal, wherein the differential mode error signal is used to control the energy allocated to the positive voltage output voltage and the negative voltage output voltage in the power stage circuit;

[0035] Generate a first pulse control signal and a second pulse control signal respectively according to the common-mode error signal and the differential-mode error signal by a pulse width modulation logic control circuit;

[0036] The current path of the power stage circuit is controlled according to the first pulse control signal and the second pulse control signal to modulate the positive output voltage and the negative output voltage.

[0037] According to the bipolar output voltage conversion circuit and bipolar output voltage conversion circuit control method provided by the present disclosure, a control circuit including a common-mode control circuit, a differential-mode control circuit, and a pulse-width modulation logic control circuit, as well as a power stage circuit, is configured so that the common-mode control circuit outputs a common-mode error signal, the differential-mode error circuit outputs a differential-mode error signal, and the pulse-width modulation logic control circuit outputs a first pulse control signal and a second pulse control signal based on the common-mode error signal and the differential-mode error signal, respectively. This enables the power stage circuit to control the current path based on the first pulse control signal and the second pulse control signal, thereby achieving simultaneous modulation of the positive and negative output voltages. Thus, the bipolar output voltage conversion circuit provided by the present disclosure can simultaneously modulate the positive and negative output voltages when a load current jump occurs, enabling the positive and negative output voltages to achieve the same transient response. Therefore, the bipolar output voltage conversion circuit provided by the present disclosure can effectively suppress intermodulation interference, reduce circuit design complexity, improve circuit robustness, and ensure output voltage stability and quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The above contents and other objects, features and advantages of the present disclosure will become more apparent through the following description of the embodiments of the present disclosure with reference to the accompanying drawings, in which:

[0039] FIG1 schematically shows a structural diagram of a bipolar output voltage converter in the related art;

[0040] FIG2 schematically shows a working state diagram of a circuit conversion circuit in the related art;

[0041] FIG3 schematically shows a structural diagram of a bipolar output voltage conversion circuit according to an embodiment of the present disclosure;

[0042] FIG4 schematically shows a structural diagram of a control circuit according to an embodiment of the present disclosure;

[0043] FIG5 schematically shows a schematic structural diagram of a power stage circuit according to an embodiment of the present disclosure;

[0044] FIG6 schematically shows a working state diagram of a power stage circuit under the control of a control circuit according to an embodiment of the present disclosure;

[0045] FIG7 schematically shows a circuit timing diagram under pulse signal control according to an embodiment of the present disclosure;

[0046] FIG8(a), FIG8(b), FIG8(c) and FIG8(d) schematically illustrate a schematic structural diagram of a power stage circuit according to an embodiment of the present disclosure;

[0047] FIG9(a), FIG9(b), FIG9(c) and FIG9(d) schematically illustrate a schematic structural diagram of another power stage circuit according to an embodiment of the present disclosure; and

[0048] FIG10 schematically shows a flow chart of a method for controlling a bipolar output voltage conversion circuit according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0049] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present disclosure. In the detailed description below, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of the embodiments of the present disclosure. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessary confusion of the concepts of the present disclosure.

[0050] The terms used herein are only for describing specific embodiments and are not intended to limit the present disclosure. The terms "comprise," "include," etc. used herein indicate the presence of the features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0051] With the development of portable devices, AMOLED display panels have been widely used in these devices due to their high display quality and compact size, meeting the display needs of portable devices. During use, AMOLED display panels generally require a bipolar output voltage conversion circuit, including both positive and negative power supplies, to provide simultaneous power. Related technologies often use a bipolar output voltage converter, with positive and negative outputs at either end of an inductor, as the power supply for AMOLED display panels.

[0052] FIG1 schematically shows a schematic diagram of the structure of a bipolar output voltage converter in the related art. As shown in FIG1 , the bipolar output voltage converter 100 includes an ordered control circuit 10 and a power stage circuit 20. The ordered control circuit 10 includes a comparator 11, an inverter 12, an amplifier 13, a current sampling circuit 14, a slope compensation circuit 15, an adder 16, a pulse width modulation circuit 17, and a logic control and gate drive circuit 18. The power stage circuit 20 includes a circuit for receiving an input voltage V IN The power input terminal 21 is used to store and transmit the input voltage V IN The inductor module 22 of the energy source is used to output a positive output voltage V at one end of the inductor module 22. OP The positive voltage output terminal 23 is used to output a negative voltage output voltage V at the other end of the inductor module 22. ON The negative voltage output terminal 24, the ground terminal 25 and the switch module 26.

[0053] The bipolar output voltage converter 100 uses the OPDC sequential linear control method to modulate the positive output voltage V OP and negative output voltage V ON The specific process is as follows:

[0054] The positive output voltage V is monitored by comparator 11 OP , positive output voltage V OP and positive reference voltage V REFP After passing through the comparator 11, the output is the first pulse signal D1'. The negative output voltage V ON After passing through the inverter 12, it is connected to the negative reference voltage V REFN After passing through the amplifier 13, a negative voltage error signal V is generated. EAN The current signal V sampled by the current sampling circuit 14 SEN The signal V is added to the slope compensation circuit 15 through the adder 16 to obtain the signal V RAMP . V RAMP Signal and V EAN The first pulse signal D1' and the second pulse signal D2' are generated after the pulse width modulation circuit 17 passes through the logic control and gate drive circuit 18 to generate the control signal SW i . Control signal SW i The power stage circuit 20 is controlled to operate in three states through the sequential linear control method of OPDC.

[0055] FIG2 schematically shows a working state diagram of a circuit conversion in the related art. In combination with FIG1 and FIG2, the power stage circuit 20 works in Φ C In the case of the state, the inductor module 22 is magnetized, the inductor module 22 accumulates energy, and the inductor current I LThe power stage circuit 20 works at Φ P In the case of the state, the inductor module 22 is demagnetized, and the inductor current I L The positive voltage output terminal 23 obtains energy. The power stage circuit 20 works at Φ N In the case of the state, the inductor module 22 is demagnetized, and the inductor current I L The negative pressure output terminal 24 obtains energy.

[0056] The bipolar output voltage converter 100 and the sequential linear control method of the OPDC used in the above-mentioned related art have at least the following problems: after the inductor module 22 is magnetized, the energy accumulated in the inductor module 22 first provides energy to the positive voltage output terminal 23 and then provides energy to the negative voltage output terminal 24 to modulate the positive voltage output voltage V OP and negative output voltage V ON More specifically, the positive output voltage V OP First get energy, then negative output voltage V ON Then get energy, positive output voltage V OP The modulation priority is higher than the negative output voltage V ON The adjustment priority results in a positive output voltage V OP and negative output voltage V ON There is mutual interference between them, and there is a cross-modulation interference problem, which affects the stability and quality of the voltage output voltage, and further affects the working stability and display quality of the AMOLED display panel. In addition, in the related art, the comparator 11 is used to monitor the positive voltage output voltage V OP , and then modulate the positive output voltage V OP , resulting in poor linear regulation capability and load regulation capability of the bipolar output voltage converter 100 .

[0057] In order to at least partially solve the technical problems existing in the related art, embodiments of the present disclosure provide a bipolar output voltage conversion circuit and a bipolar output voltage conversion circuit control method, which can be applied to the field of voltage conversion.

[0058] FIG3 schematically illustrates a schematic diagram of the structure of a bipolar output voltage conversion circuit according to an embodiment of the present disclosure. As shown in FIG3 , the bipolar output voltage conversion circuit 200 according to the embodiment of the present disclosure includes a control circuit 30 and a power stage circuit 20. The control circuit 30 includes a common-mode control circuit 31, a differential-mode control circuit 32, and a pulse-width modulation logic control circuit 33.

[0059] The common mode control circuit 31 is used to control the positive voltage error signal V EAP and negative pressure error signal V EAN Output common mode error signal V EA_CM , common mode error signal VEA_CM It is used to control the total energy input into the power stage circuit 20 .

[0060] The differential mode control circuit 32 is used to receive the positive voltage error signal V EAP and negative pressure error signal V EAN Output differential error signal V EA_DM , differential mode error signal V EA_DM Used to control the positive output voltage V distributed to the power stage circuit 20 OP and negative output voltage V ON energy.

[0061] The pulse width modulation logic control circuit 33 is connected to the common mode control circuit 31 and the differential mode control circuit 32 respectively, and is used to receive the common mode error signal V EA_CM and differential error signal V EA_DM The first pulse control signal D1 and the second pulse control signal D2 are outputted respectively. It should be noted that the working mode of the pulse width modulation logic control circuit 33 is the peak current mode.

[0062] The power stage circuit 20 is used to control the current path according to the first pulse control signal D1 and the second pulse control signal D2 to modulate the positive output voltage V OP and negative output voltage V ON .

[0063] Thus, the control circuit 30 generates a first pulse control signal D1 and a second pulse control signal D2 for controlling the current path, so that the bipolar output voltage conversion circuit 200 realizes the positive output voltage V OP and negative output voltage V ON More specifically, the bipolar output voltage conversion circuit 200 provided by the present disclosure can simultaneously modulate the positive output voltage V when the load current jumps. OP and negative output voltage V ON , making the positive output voltage V OP and negative output voltage V ON The same transient response can be achieved, effectively suppressing intermodulation interference. Furthermore, the bipolar output voltage conversion circuit 200 provided by the present disclosure has a simple structure, low manufacturing cost, strong stability, and high reliability. This effectively reduces the complexity of circuit design, improves circuit robustness, and ensures the stability and quality of the output voltage.

[0064] FIG4 schematically shows a schematic diagram of the structure of the control circuit according to an embodiment of the present disclosure. As shown in FIG4 , the control circuit 30 may further include a positive voltage error amplifier 34 and a negative voltage error amplifier 35. The positive voltage error amplifier 34 is used to output the positive voltage V according to the received positive voltage.OP and positive reference voltage V REFP Output positive pressure error signal V EAP . Positive reference voltage V REFP It is a preset reference voltage, which can be understood by those skilled in the art and will not be described in detail here. EAP Can be used to reflect the positive output voltage V OP With positive reference voltage V REFP The output terminal of the positive voltage error amplifier 34 is connected to the input terminal of the common mode control circuit 31 and the input terminal of the differential mode control circuit 32 respectively.

[0065] In one possible implementation, the positive pressure error signal V EAP The positive voltage reference voltage V can be obtained by the positive voltage error amplifier 34 REFP and positive output voltage V OP The difference between the two is obtained by amplifying the gain of the positive voltage error amplifier 34, that is, V EAP =A1*(V REFP -V OP ), where: V EAP is the positive voltage error signal; A1 is the gain multiple of the positive voltage error amplifier 34; V REFP is the positive reference voltage; V OP is the positive output voltage.

[0066] The negative voltage error amplifier 35 is used to output a voltage V according to the received negative voltage. ON and negative reference voltage V REFN Output negative pressure error signal V EAN . Negative reference voltage V REFN It is a preset reference voltage, which can be understood by those skilled in the art and will not be described in detail here. EAN Can be used to reflect the negative output voltage V ON With negative reference voltage V REFN The output terminal of the negative voltage error amplifier 35 is connected to the input terminal of the common mode control circuit 31 and the input terminal of the differential mode control circuit 32 respectively.

[0067] It should be noted that in the bipolar output voltage conversion circuit 200, the negative reference voltage V REFN and positive reference voltage V REFP are all positive, so it is necessary to first ON After the polarity is reversed by the reverse circuit 36, it can be input into the negative voltage error amplifier 35 to compare with the negative voltage reference voltage V REFP Make a comparison.

[0068] In one feasible implementation, the negative pressure error signal V EAN The negative voltage reference voltage V can be obtained by the negative voltage error amplifier 35 REFP and the negative output voltage V after the polarity is reversed by the reverse circuit 36 ON The difference between the two is obtained by amplifying the gain of the negative voltage error amplifier 35, that is, V EAN =A2*(V REFN -|V ON |), where: V E AN is the negative voltage error signal; A2 is the gain multiple of the negative voltage error amplifier 35; V REFN is the negative reference voltage; |V ON | is the negative output voltage V ON The absolute value of .

[0069] Therefore, the positive voltage error signal V is obtained by the positive voltage error amplifier 34 and the negative voltage error amplifier 35. EAP and negative pressure error signal V EAN Can more accurately reflect the positive output voltage V OP and positive reference voltage V REFP The difference between the negative output voltage V ON and negative reference voltage V REFN The difference between the two increases the bipolar output voltage conversion circuit 200 while modulating the positive output voltage V OP and negative output voltage V ON The accuracy of the bipolar output voltage conversion circuit 200 is improved to improve the positive output voltage V OP and negative output voltage V ON Linear adjustment capability and load adjustment capability. And the positive output voltage V OP and negative output voltage V ON The modulation is performed respectively through the positive voltage error amplifier 34 and the negative voltage error amplifier 35 , which has a large loop gain and can effectively improve the stability and reliability of voltage conversion.

[0070] According to an embodiment of the present disclosure, as shown in FIG4 , the common-mode error signal V EA_CM The positive voltage error signal V EAP and negative pressure error signal V EAN Furthermore, the positive voltage error signal V EAP and negative pressure error signal V EAN Add together to get the common mode error signal V EA_CM , that is, V EA_CM =V EAP +V EAN .

[0071] Differential mode error signal V EA_DM The positive pressure error signal V EAP and the negative pressure error signal V EAN Further, the positive voltage error signal V EAP Subtract the negative pressure error signal V EAN Get the differential mode error signal V EA_DM , that is, V EA_DM =V EAP -V EAN .

[0072] Therefore, the common-mode error signal V EA_CM To achieve V OP +|V ON |Modulation, through the differential mode error signal V EA_DM To achieve V OP -|V ON | modulation.

[0073] FIG5 schematically shows a schematic diagram of the structure of a power stage circuit according to an embodiment of the present disclosure. As shown in FIG5 , the power stage circuit 20 may include the following modules: a power input terminal 21 for receiving an input voltage V IN ; Inductor module 22, for storing and transmitting input voltage V IN Positive voltage output terminal 23, for outputting a positive voltage output voltage V at one end of the inductor module 22 OP Negative voltage output terminal 24, for outputting a negative voltage output voltage V at the other end of the inductor module 22 ON Ground terminal 25; and the switch module 26, connected to the output terminal of the pulse width modulation logic control circuit 33, for controlling the current path according to the received first pulse control signal D1 and the second pulse control signal D2.

[0074] The control logic of the control circuit of the embodiment of the present disclosure is shown in Table 1:

[0075] Table 1

[0076] As can be seen from Table 1, the control logic and current path adopted by the bipolar output voltage conversion circuit 200 include:

[0077] When the first pulse control signal D1 is at a high level and the second pulse control signal D2 is at a high level, that is, when the logic value of "D1D2" is "11", the current in the power stage circuit 20 is controlled by the switch module 26 to operate in the first path Φ1. The first path Φ1 is the path for the current in the power stage circuit 20 to flow from the power input terminal 21 to the ground terminal 25. More specifically, the first path Φ1 is the path for the current to flow out of the power input terminal 21, flow through the inductor module 22, and flow to the ground terminal 25. Therefore, the input voltage V provided by the power input terminal 21 is IN The inductor module 22 is charged and stored with energy.

[0078] When the first pulse control signal D1 is at a low level and the second pulse control signal D2 is at a low level, that is, when the logic value of "D1D2" is "00", the current in the power stage circuit 20 is controlled by the switch module 26 to operate in the second path Φ2. The second path Φ2 is the path for the current in the power stage circuit 20 to flow from the negative voltage output terminal 24 to the positive voltage output terminal 23. More specifically, the second path Φ2 is the current flowing out of the negative voltage output terminal 24, flowing through the inductor module 22, and flowing to the positive voltage output terminal 23. As a result, the inductor module 22 releases electrical energy, so that the positive voltage output terminal 23 and the negative voltage output terminal 24 are energized at the same time, realizing the bipolar output voltage conversion circuit 200 for the positive voltage output voltage V OP and negative output voltage V ON Simultaneous modulation.

[0079] When the first pulse control signal D1 is at a low level and the second pulse control signal D2 is at a high level, that is, when the logic value of "D1D2" is "01", the current in the power stage circuit 20 is controlled by the switch module 26 to operate in the third path Φ3. The third path Φ3 is the path for the current in the power stage circuit 20 to flow from the negative voltage output terminal 24 to the ground terminal 25. More specifically, the third path Φ3 is the current flowing out of the negative voltage output terminal 24, flowing through the inductor module 22, and flowing to the ground terminal 25. As a result, the inductor module 22 releases electrical energy, and only the negative voltage output terminal 24 receives energy, thereby increasing the negative voltage output voltage V ON .

[0080] When the first pulse control signal D1 is at a high level and the second pulse control signal D2 is at a low level, that is, when the logic value of "D1D2" is "10", the current in the power stage circuit 20 is controlled by the switch module 26 to operate in the fourth path Φ4. The fourth path Φ4 is the path for the current in the power stage circuit 20 to flow from the power input terminal 21 to the positive voltage output terminal 23. More specifically, the fourth path Φ4 is the current flowing out of the power input terminal 21, flowing through the inductor module 11, and flowing to the positive voltage output terminal 23. As a result, the inductor module 22 releases electrical energy, and only the positive voltage output terminal 23 receives energy, thereby increasing the positive voltage output voltage V OP .

[0081] FIG6 schematically shows a working state diagram of a power stage circuit under control of a control circuit according to an embodiment of the present disclosure. FIG7 schematically shows a circuit timing diagram under pulse signal control according to an embodiment of the present disclosure. According to an embodiment of the present disclosure, as shown in FIG6 and FIG7, the power stage circuit 20 is configured as follows:

[0082] According to the differential mode error signal V EA_DM The following operation is performed: the differential error signal V EA_DM When the positive pressure error signal V is zero, EAP and the negative pressure error signal V EAN Equal, positive output voltage V OP and negative output voltage V ON The same energy is required. The pulse width of the first pulse control signal D1 and the second pulse control signal D2 generated by the pulse width modulation logic control circuit 33 are the same. The current in the power stage circuit 20 operates alternately in the first path Φ1 and the second path Φ2 under the control of the switch module 26. Thus, the same energy from the power input terminal 21 is simultaneously transmitted to the positive voltage output terminal 23 and the negative voltage output terminal 24 through the bipolar output voltage conversion circuit 200. The input voltage V IN At the same time, it is converted into a positive output voltage V OP and negative output voltage V ON , and the positive output voltage V OP and negative output voltage V ON Get the same energy.

[0083] The differential mode error signal V EA_DM When the positive pressure error signal V is greater than zero, EAP Higher than the negative pressure output error signal V EAN , compared to the negative output voltage V ON , positive output voltage V OP More energy is needed, and the pulse width of the first pulse control signal D1 generated by the pulse width modulation logic control circuit 33 is wider than the pulse width of the second pulse control signal D2. Under the control of the switch module 26, the current in the power stage circuit 20 alternately operates in the first path Φ1, the fourth path Φ4, and the second path Φ2. As a result, the energy of the power input terminal 21 is simultaneously transmitted to the positive voltage output terminal 23 and the negative voltage output terminal 24 through the bipolar output voltage conversion circuit 200, and more energy is transmitted to the positive voltage output terminal 23 than to the negative voltage output terminal 24. That is, the input voltage V IN At the same time, it is converted into a positive output voltage V OP and negative output voltage V ON , and the positive output voltage V OP The energy obtained is higher than the negative output voltage V ON The energy obtained.

[0084] The differential mode error signal V EA_DM When the positive pressure error signal V is less than zero, EAP Lower than the negative voltage input error signal V EAN , compared to the positive output voltage V OP , negative output voltage V ON More energy is needed. The pulse width of the first pulse control signal D1 generated by the pulse width modulation logic control circuit 33 is narrower than the pulse width of the second pulse control signal D2. Under the control of the switch module 26, the current in the power stage circuit 20 alternately operates in the first path Φ1, the third path Φ3, and the second path Φ2. As a result, the energy of the power input terminal 21 is simultaneously transmitted to the positive voltage output terminal 23 and the negative voltage output terminal 24 through the bipolar output voltage conversion circuit 200, and more energy is transmitted to the negative voltage output terminal 24 than to the positive voltage output terminal 23. That is, the input voltage V IN At the same time, it is converted into a positive output voltage V OP and negative output voltage V ON , and the negative output voltage V ON The energy obtained is higher than the positive output voltage V OP The energy obtained.

[0085] The common-mode error signal V EA_CM In the case of rising, the positive output voltage V OP and negative output voltage V ON When more energy is needed, the pulse width of the first pulse control signal D1 and the pulse width of the second pulse control signal D2 are increased by the pulse width modulation logic control circuit 33, thereby increasing the working time of the current in the power stage circuit 20 working in the first path Φ1, so that the inductor module 22 accumulates more energy.

[0086] The common-mode error signal V EA_CM In the case of falling, the positive output voltage V OP and negative output voltage V ON When more energy is not needed, the pulse width of the first pulse control signal D1 and the pulse width of the second pulse control signal D2 are reduced by the pulse width modulation logic control circuit 33, thereby reducing the time for the current in the power stage circuit 20 to operate in the first path Φ1, so that the inductor module 22 accumulates more energy.

[0087] FIG8(a), FIG8(b), FIG8(c) and FIG8(d) are schematic diagrams of a power stage circuit according to an embodiment of the present disclosure. In addition to the modules shown in FIG5 , the power stage circuit 20 may also include a positive output capacitor C OP and negative output capacitor C ONThe switch module 26 may include a first switch SW1 , a second switch SW2 , a third switch SW3 , and a fourth switch SW4 .

[0088] The connection relationship between the modules in the power stage circuit 20 is as follows: the first end of the first switch SW1 is connected to the power input terminal 21, the second end of the first switch SW1 is connected to the first end LX1 of the inductor module 22, the second end LX2 of the inductor module 22 is connected to the first end of the third switch SW3, and the second end of the third switch SW3 is connected to the positive output capacitor C OP The first terminal of the positive output capacitor C OP The second end is connected to the negative output capacitor C ON The first terminal, negative output capacitor C ON The second end of the positive output capacitor C is connected to the first end of the fourth switch SW4, the second end of the fourth switch SW4 is connected to the first end LX1 of the inductor module, and the positive output capacitor C OP The second terminal and the negative output capacitor C ON The first ends of the second switch SW2 are connected to the ground end 25 , the first end of the second switch SW2 is connected to the second end LX2 of the inductor module 22 , and the second end of the second switch SW2 is connected to the ground end 25 .

[0089] The first switch SW1, the second switch SW2, the third switch SW3 and the fourth switch SW4 are configured as follows:

[0090] As shown in Figure 8(a), when the first pulse control signal D1 and the second pulse control signal D2 are both high, the first switch SW1 and the second switch SW2 are simultaneously turned on, while the third switch SW3 and the fourth switch SW4 are simultaneously turned off. The current in the power stage circuit 20 flows along the first path Φ1. The current flows from the power input terminal 21, through the inductor module 22, and to the ground terminal 25, where the inductor module 22 is charged and stores energy.

[0091] As shown in FIG8(b), when the first pulse control signal D1 is at a low level and the second pulse control signal D2 is at a low level, the first switch SW1 and the second switch SW2 are synchronously turned off, the third switch SW3 and the fourth switch SW4 are synchronously turned on, and the current in the power stage circuit 20 operates in the second path Φ2. The current flows out from the negative voltage output terminal 24, flows through the inductor module 22, and flows to the positive voltage output terminal 23. More specifically, the current flows from the negative output capacitor C ON The current flows out of the second end, flows through the inductor module 22, and flows to the positive output capacitor C OP The first end.

[0092] As shown in FIG8(c), when the first pulse control signal D1 is at a low level and the second pulse control signal D2 is at a high level, the first switch SW1 and the third switch SW3 are synchronously disconnected, the second switch SW2 and the fourth switch SW4 are synchronously turned on, and the current in the power stage circuit 20 operates in the third path Φ3. The current flows out from the negative voltage output terminal 24. More specifically, the current flows from the negative output capacitor C ON The current flows out of the second end of the inductor module 22 and flows to the ground terminal 25, while no current flows into the positive output capacitor C OP The first terminal, positive output voltage V OP Falling, negative output voltage V ON rise.

[0093] As shown in Figure 8(d), when the first pulse control signal D1 is at a high level and the second pulse control signal D2 is at a low level, the first switch SW1 and the third switch SW3 are turned on synchronously, and the second switch SW2 and the fourth switch SW4 are turned off synchronously. The current in the power stage circuit 20 operates in the fourth path Φ4. The current flows out from the power input terminal 21, flows through the inductor module 22, and flows to the positive output capacitor C OP The first terminal, while no current flows from the negative output capacitor C ON The second end flows out, the positive output voltage V OP Rising, negative output voltage V ON decline.

[0094] Figures 9(a), 9(b), 9(c), and 9(d) are schematic diagrams of the structure of another power stage circuit provided in an embodiment of the present disclosure. The power stage circuit 20 may further include a conducting capacitor. The switch module further includes a fifth switch SW5. A first end of the conducting capacitor is connected to the first end LX1 of the inductor module 22. A second end of the conducting capacitor is connected to the first end of the fifth switch SW5. A second end of the fifth switch SW5 is connected to the second end of the second switch SW2.

[0095] The first switch SW1, the second switch SW2, the third switch SW3, the fourth switch SW4 and the fifth switch SW5 are configured as follows:

[0096] As shown in FIG9( a ), when the first pulse control signal D1 is at a high level and the second pulse control signal D2 is at a high level, the first switch SW1 , the second switch SW2 , and the fifth switch SW5 are synchronously turned on, and the third switch SW3 and the fourth switch SW4 are synchronously turned off, and the current in the power stage circuit 20 operates in the first path Φ1.

[0097] As shown in FIG9( b ), when the first pulse control signal D1 is at a low level and the second pulse control signal D2 is at a low level, the first switch SW1 , the second switch SW2 , and the fifth switch SW5 are synchronously disconnected, and the third switch SW3 and the fourth switch SW4 are synchronously turned on, and the current in the power stage circuit 20 operates in the second path Φ2 .

[0098] As shown in FIG9( c ), when the first pulse control signal D1 is at a low level and the second pulse control signal D2 is at a high level, the first switch SW1 , the third switch SW3 , and the fifth switch SW5 are synchronously disconnected, and the second switch SW2 and the fourth switch SW4 are synchronously turned on, and the current in the power stage circuit 20 operates in the third path Φ3 .

[0099] As shown in FIG9( d ), when the first pulse control signal D1 is at a high level and the second pulse control signal D2 is at a low level, the first switch SW1 , the third switch SW3 , and the fifth switch SW5 are synchronously turned on, the second switch SW2 and the fourth switch SW4 are synchronously turned off, and the current in the power stage circuit 20 operates in the fourth path Φ4 .

[0100] The first path Φ1, the second path Φ2, the third path Φ3 and the fourth path Φ4 shown in Figures 9(a), 9(b), 9(c) and 9(d), respectively, are consistent with the first path Φ1, the second path Φ2, the third path Φ3 and the fourth path Φ4 shown in Figures 8(a), 8(b), 8(c) and 8(d), and are not further described here.

[0101] It should be understood that the structural diagrams of the two exemplary power stage circuits provided in the embodiments of the present disclosure are intended to illustrate the feasibility of the bipolar output voltage conversion circuit 200 provided in the present disclosure.

[0102] According to an embodiment of the present disclosure, the bipolar output voltage conversion circuit 200 may be a SIBO DC-DC bipolar output voltage converter. The SIBO DC-DC bipolar output voltage converter can output a positive output voltage V at both ends of the inductor. OP and negative output voltage V ON Furthermore, the SIBO DC-DC bipolar output voltage converter uses only one inductor, effectively reducing the manufacturing cost and size of off-chip components. The SIBO DC-DC bipolar output voltage converter circuit can be applied to display panels, such as, but not limited to, AMOLED display panels.

[0103] An embodiment of the present disclosure provides a bipolar output voltage conversion circuit control method. As shown in FIG10 , the bipolar output voltage conversion circuit control method 1000 includes:

[0104] First, at step S1001 , a positive voltage error signal and a negative voltage error signal are received by a common mode control circuit, and a common mode error signal is output. The common mode error signal is used to control the total energy input into the power stage circuit.

[0105] Secondly, at step S1002, a positive voltage error signal and a negative voltage error signal are received by a differential mode control circuit, and a differential mode error signal is output. The differential mode error signal is used to control the energy allocated to the positive voltage output voltage and the negative voltage output voltage in the power stage circuit.

[0106] Then, at step S1003 , a first pulse control signal and a second pulse control signal are generated respectively according to the common-mode error signal and the differential-mode error signal by a pulse width modulation logic control circuit.

[0107] Finally, at step S1004 , the current path of the power stage circuit is controlled according to the first pulse control signal and the second pulse control signal to modulate the positive output voltage and the negative output voltage.

[0108] Compared with the related art, the bipolar output voltage conversion circuit and the bipolar output voltage conversion circuit control method provided by the present disclosure can generate a common mode error signal V based on the common mode control circuit 31 and the differential mode control circuit 32. EA_CM and differential error signal V EA_DM , the pulse width modulation logic control circuit 33 is based on the common mode error signal V EA_CM and differential error signal V EA_DM Generate a first pulse control signal D1 and a second pulse control signal D2 to control the current path to achieve a positive output voltage V in the power stage circuit 20 OP and negative output voltage V ON Simultaneous modulation effectively suppresses intermodulation interference and improves the stability and quality of the output voltage.

[0109] Those skilled in the art will appreciate that the features described in the various embodiments and / or claims of this disclosure may be combined and / or coupled in various ways, even if such combinations and / or couplings are not explicitly described in this disclosure. In particular, the features described in the various embodiments and / or claims of this disclosure may be combined and / or coupled in various ways without departing from the spirit and teachings of this disclosure. All such combinations and / or couplings are intended to fall within the scope of this disclosure.

[0110] The embodiments of the present disclosure are described above. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of the present disclosure. Although each embodiment has been described separately above, this does not mean that the measures in each embodiment cannot be used in combination to advantage. The scope of the present disclosure is defined by the appended claims and their equivalents. Without departing from the scope of the present disclosure, those skilled in the art may make various substitutions and modifications, which should all fall within the scope of the present disclosure.

Claims

1. A bipolar output voltage conversion circuit, comprising: A control circuit, comprising: A common-mode control circuit, configured to output a common-mode error signal according to the received positive voltage error signal and negative voltage error signal, and the common-mode error signal is used to control the total energy input to the power stage circuit; A differential-mode control circuit, configured to output a differential-mode error signal according to the received positive voltage error signal and negative voltage error signal, and the differential-mode error signal is used to control the energy allocated to the positive voltage output and negative voltage output of the power stage circuit; and A pulse width modulation logic control circuit, respectively connected to the common-mode control circuit and the differential-mode control circuit, configured to output a first pulse control signal and a second pulse control signal according to the received common-mode error signal and differential-mode error signal; The power stage circuit, configured to control the current path according to the first pulse control signal and the second pulse control signal to modulate the positive voltage output and the negative voltage output.

2. The bipolar output voltage conversion circuit according to claim 1, wherein the control circuit further comprises: A positive voltage error amplifier, configured to output the positive voltage error signal according to the received positive voltage output and positive voltage reference voltage, and the output end of the positive voltage error amplifier is respectively connected to the input end of the common-mode control circuit and the input end of the differential-mode control circuit; And A negative voltage error amplifier, configured to output the negative voltage error signal according to the received negative voltage output and negative voltage reference voltage, and the output end of the negative voltage amplifier is respectively connected to the input end of the common-mode control circuit and the input end of the differential-mode control circuit.

3. The bipolar output voltage conversion circuit according to claim 1 or 2, wherein the common-mode error signal is obtained by adding the positive voltage error signal and the negative voltage error signal; the differential-mode error signal is obtained by subtracting the negative voltage error signal from the positive voltage error signal.

4. The bipolar output voltage conversion circuit according to claim 2, wherein the power stage circuit comprises: A power input terminal, configured to receive an input voltage; An inductor module, configured to store and transfer the energy of the input voltage; A positive voltage output terminal, configured to output the positive voltage output at one end of the inductor module; A negative voltage output terminal, configured to output the negative voltage output at the other end of the inductor module; A ground terminal; And A switch module, connected to the output end of the pulse width modulation logic control circuit, configured to control the current path according to the received first Pulse control signal and the second pulse control signal.

5. The bipolar output voltage conversion circuit according to claim 4, wherein the current path comprises: When the first pulse control signal is at a high level and the second pulse control signal is at a high level, the switch module is used to control the current in the power stage circuit to work in a first path, and the first path is the path where the current in the power stage circuit flows from the power input terminal to the ground terminal; When the first pulse control signal is at a low level and the second pulse control signal is at a low level, the switch module is used to control the current in the power stage circuit to work on a second path, where the second path is the path for the current in the power stage circuit to flow from the negative voltage output terminal to the positive voltage output terminal; When the first pulse control signal is at a low level and the second pulse control signal is at a high level, the switch module is used to control the current in the power stage circuit to work on a third path, where the third path is the path for the current in the power stage circuit to flow from the negative voltage output terminal to the ground terminal; When the first pulse control signal is at a high level and the second pulse control signal is at a low level, the switch module is used to control the current in the power stage circuit to work on a fourth path, where the fourth path is the path for the current in the power stage circuit to flow from the power input terminal to the positive voltage output terminal.

6. The bipolar output voltage conversion circuit according to claim 5, wherein the power stage circuit is configured as follows: When the differential mode error signal is zero, the pulse widths of the first pulse control signal and the second pulse control signal generated by the pulse width modulation logic control circuit are the same, and the current in the power stage circuit alternately works on the first path and the second path under the control of the switch module; When the differential mode error signal is greater than zero, the pulse width of the first pulse control signal generated by the pulse width modulation logic control circuit is wider than the pulse width of the second pulse control signal, and the current in the power stage circuit alternately works on the first path, the fourth path, and the second path under the control of the switch module; When the differential mode error signal is less than zero, the pulse width of the first pulse control signal generated by the pulse width modulation logic control circuit is narrower than the pulse width of the second pulse control signal, and the current in the power stage circuit alternately works on the first path, the third path, and the second path under the control of the switch module; When the common mode error signal is rising, the pulse width modulation logic control circuit increases the pulse widths of the first pulse control signal and the second pulse control signal, and increases the working time of the current in the power stage circuit on the first path; When the common mode error signal is falling, the pulse width modulation logic control circuit decreases the pulse widths of the first pulse control signal and the second pulse control signal, and decreases the time of the current in the power stage circuit working on the first path.

7. The bipolar output voltage conversion circuit according to claim 5, wherein the power stage circuit further includes a positive output capacitor and a negative output capacitor, the switching module includes a first switch, a second switch, a third switch, and a fourth switch, a first end of the first switch is connected to the power input terminal, a second end of the first switch is connected to a first end of the inductor module, a second end of the inductor module is connected to a first end of the third switch, a second end of the third switch is connected to a first end of the positive output capacitor, a second end of the positive output capacitor is connected to a first end of the negative output capacitor, a second end of the negative output capacitor is connected to a first end of the fourth switch, a second end of the fourth switch is connected to the first end of the inductor module, a second end of the positive output capacitor and a first end of the negative output capacitor are commonly connected to the ground terminal, a first end of the second switch is connected to the second end of the inductor module, and a second end of the second switch is connected to the ground terminal; Wherein the first switch, the second switch, the third switch, and the fourth switch are configured as follows: When the first pulse control signal is at a high level and the second pulse control signal is at a high level, the first switch and the second switch are synchronously turned on, the third switch and the fourth switch are synchronously turned off, and the current in the power stage circuit operates in the first path; When the first pulse control signal is at a low level and the second pulse control signal is at a low level, the first switch and the second switch are synchronously turned off, the third switch and the fourth switch are synchronously turned on, and the current in the power stage circuit operates in the second path; When the first pulse control signal is at a low level and the second pulse control signal is at a high level, the first switch and the third switch are synchronously turned off, the second switch and the fourth switch are synchronously turned on, and the current in the power stage circuit operates in the third path; When the first pulse control signal is at a high level and the second pulse control signal is at a low level, the first switch and the third switch are synchronously turned on, the second switch and the fourth switch are synchronously turned off, and the current in the power stage circuit operates in the fourth path.

8. The bipolar output voltage conversion circuit according to claim 7, wherein the power stage circuit further includes a conducting capacitor, the switching module further includes a fifth switch, a first end of the conducting capacitor is connected to the first end of the inductor module, a second end of the conducting capacitor is connected to a first end of the fifth switch, and a second end of the fifth switch is connected to a second end of the second switch; Wherein the first switch, the second switch, the third switch, the fourth switch, and the fifth switch are configured as follows: When the first pulse control signal is at a high level and the second pulse control signal is at a high level, the first switch, the second switch, and the fifth switch are synchronously turned on, the third switch and the fourth switch are synchronously turned off, and the current in the power stage circuit operates in the first path; When the first pulse control signal is at a low level and the second pulse control signal is at a low level, the first switch, the second switch, and the fifth switch are synchronously turned off, and the third switch and the fourth switch are synchronously turned on. The current in the power stage circuit operates on the second path. When the first pulse control signal is at a low level and the second pulse control signal is at a high level, the first switch, the third switch, and the fifth switch are synchronously turned off, the second switch and the fourth switch are synchronously turned on, and the current in the power stage circuit operates on the third path. When the first pulse control signal is at a high level and the second pulse control signal is at a low level, the first switch, the third switch, and the fifth switch are synchronously turned on, the second switch and the fourth switch are synchronously turned off, and the current in the power stage circuit operates on the fourth path.

9. The bipolar output voltage conversion circuit according to claim 1, wherein the bipolar output voltage conversion circuit is a single-inductor bipolar output DC-DC bipolar output voltage converter.

10. A method for controlling a bipolar output voltage conversion circuit, comprising: Receiving a positive voltage error signal and a negative voltage error signal through a common-mode control circuit, and outputting a common-mode error signal, the common-mode error signal being used to control the total energy input to the power stage circuit; Receiving the positive voltage error signal and the negative voltage error signal through a differential-mode control circuit, and outputting a differential-mode error signal, the differential-mode error signal being used to control the energy allocated to the positive voltage output and the negative voltage output of the power stage circuit; Generating a first pulse control signal and a second pulse control signal respectively according to the common-mode error signal and the differential-mode error signal through a pulse width modulation logic control circuit; Controlling the current path of the power stage circuit according to the first pulse control signal and the second pulse control signal to modulate the positive voltage output and the negative voltage output.

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