Common electrode voltage generating circuit, power supply device and electronic equipment

Abstract

The invention is suitable for the technical field of electronic circuits, and provides a common electrode voltage generation circuit, a power supply device and electronic equipment. The common electrode voltage generating circuit comprises a bias current generating module, a resistor module, a first operational amplifier module, a voltage dividing module, a second operational amplifier module and a voltage output module, the first operational amplifier module is electrically connected with the bias current generating module, the resistor module and the voltage dividing module, and the voltage output module is electrically connected with the voltage dividing module and the second operational amplifier module. The bias current generating module generates bias current, the resistor module generates bias voltage, and the first operational amplifier module outputs second node voltage. The voltage dividing module outputs a first voltage, the second operational amplifier module outputs a second voltage, and the voltage output module outputs a common electrode voltage. According to the common electrode voltage generation circuit provided by the embodiment of the invention, the interference of AVEE negative voltage on the common electrode voltage is reduced, and the noise suppression capability of the common electrode voltage on the AVEE negative voltage is effectively improved.

Description

Technical Field

[0001] This application belongs to the technical field of electronic circuits, and particularly relates to a common electrode voltage generation circuit, a power supply device, and an electronic device. Background Art

[0002] In electronic devices such as LCD (Liquid Crystal Display), VCOM (Common Voltage) is a key electrical parameter. Its polarity selection is closely related to the driving method, power consumption optimization, and display performance, and directly affects the display quality and stability. To dynamically adjust VCOM to improve the trailing effect of high-refresh-rate images, it is necessary to set it in the form of independent configuration outputs of two sets of parameters, VCOMMIN and OFFSET. Among them, VCOMMIN and OFFSET can adjust the output voltage by changing the internal register parameters. In the prior art, multiple operational amplifiers are usually used to generate positive and negative voltages through internal reference voltage operations. However, in this solution, multiple operational amplifiers all use the AVEE negative voltage as the reference ground. Since the AVEE negative voltage is usually generated by a switching power supply and has a large noise, there is a large noise in VCOM. Summary of the Invention

[0003] The embodiments of this application provide a common electrode voltage generation circuit, a power supply device, and an electronic device, which can solve the problem that in the existing common electrode voltage generation circuit, multiple operational amplifiers all use the AVEE negative voltage as the reference ground, resulting in a large noise in VCOM.

[0004] In a first aspect, the embodiments of this application provide a common electrode voltage generation circuit, including a bias current generation module, a resistor module, a first operational amplifier module, a voltage division module, a second operational amplifier module, and a voltage output module. The first operational amplifier module is electrically connected to the bias current generation module, the resistor module, and the voltage division module respectively, and the voltage output module is electrically connected to the voltage division module and the second operational amplifier module respectively; The bias current generation module is used to generate a bias current; the resistor module is used to generate a bias voltage according to the bias current; the first operational amplifier module is used to output a second node voltage according to a reference voltage and a first node voltage, where the first node voltage is the voltage at the common terminal of the first operational amplifier module and the bias current generation module, the second node voltage is the voltage at the common terminal of the first operational amplifier module and the voltage division module, and the second node voltage is the sum of the reference voltage and the bias voltage; the voltage division module is used to output a first voltage to the voltage output module according to the second node voltage; the second operational amplifier module is used to output a second voltage to the voltage output module according to a configured voltage; the voltage output module is used to output a common electrode voltage according to the first voltage and the second voltage.

[0005] In a possible implementation of the first aspect, the bias current generation module includes a current source. A first end of the current source is electrically connected to the first operational amplifier module and the resistor module respectively, and a second end of the current source is grounded. In a possible implementation of the first aspect, the first operational amplifier module includes a first operational amplifier. A first input terminal of the first operational amplifier is used to receive the reference voltage. A second input terminal of the first operational amplifier is electrically connected to the bias current generation module and the resistor module respectively. An output terminal of the first operational amplifier is electrically connected to the resistor module and the voltage division module respectively. In a possible implementation of the first aspect, the voltage division module includes a first resistor and a second resistor. A first end of the first resistor is electrically connected to the first operational amplifier module and the resistor module respectively. A second end of the first resistor is electrically connected to a first end of the second resistor and the voltage output module respectively. A second end of the second resistor is grounded. In a possible implementation of the first aspect, the second operational amplifier module includes a second operational amplifier. A first input terminal of the second operational amplifier is used to receive the configuration voltage. A second input terminal of the second operational amplifier is electrically connected to an output terminal of the second operational amplifier and the voltage output module respectively. In a possible implementation of the first aspect, the resistor module includes a third resistor. A first end of the third resistor is electrically connected to the first operational amplifier module and the bias current generation module respectively. A second end of the third resistor is electrically connected to the first operational amplifier module and the voltage division module respectively. In a possible implementation of the first aspect, the output module includes a fourth resistor, a fifth resistor, and a third operational amplifier. A first end of the fourth resistor is electrically connected to the second operational amplifier module. A second end of the fourth resistor is electrically connected to a first end of the fifth resistor and a second input terminal of the third operational amplifier respectively. A first input terminal of the third operational amplifier is electrically connected to the voltage division module. An output terminal of the third operational amplifier is electrically connected to a second end of the fifth resistor. In a possible implementation of the first aspect, the output module further includes a fourth operational amplifier. A first input terminal of the fourth operational amplifier is electrically connected to an output terminal of the third operational amplifier and a second end of the fifth resistor respectively. A second input terminal of the fourth operational amplifier is electrically connected to an output terminal of the fourth operational amplifier. In a second aspect, an embodiment of the present application provides a power supply device, including the common electrode voltage generation circuit according to any one of the first aspect.

[0006] In a third aspect, an embodiment of the present application provides an electronic device, including the power supply device according to the second aspect.

[0007] The beneficial effects of the embodiments of the present application compared with the prior art are as follows: The common electrode voltage generation circuit provided by the embodiments of the present application includes a bias current generation module, a resistor module, a first operational amplifier module, a voltage division module, a second operational amplifier module, and a voltage output module. Among them, the bias current generation module can generate a bias current. When the bias current flows through the resistor module, a voltage drop, that is, a bias voltage, can be generated. Therefore, the bias voltage is equal to the product of the bias current and the resistance value of the resistor module. The first operational amplifier module outputs a second node voltage according to the reference voltage and the first node voltage, and the second node voltage is the sum of the reference voltage and the bias voltage. The voltage division module divides the received second node voltage and outputs a first voltage to the voltage output module. The second operational amplifier module outputs a second voltage to the voltage output module according to the configured voltage, and the voltage output module outputs the common electrode voltage according to the first voltage and the second voltage. It can be seen that in the process of outputting the common electrode voltage by the common electrode voltage generation circuit provided by the embodiments of the present application, since the second node voltage output by the first operational amplifier module is equal to the sum of the reference voltage and the bias voltage, and both the reference voltage and the bias voltage are positive voltages, the second node voltage is a positive voltage. This enables the devices in the first operational amplifier module to use GND as the reference ground, without the need to use the AVEE negative voltage as the reference ground. Thus, the interference of the common electrode voltage by the AVEE negative voltage is reduced, and the noise suppression ability of the common electrode voltage to the AVEE negative voltage is effectively improved. Description of the Drawings

[0008] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0009] Figure 1 is a connection schematic diagram of an existing common electrode voltage generation circuit; Figure 2 is a principle block diagram of a common electrode voltage generation circuit provided by an embodiment of the present application; Figure 3 is a circuit connection schematic diagram of a common electrode voltage generation circuit provided by an embodiment of the present application.

[0010] In the figure, 10 is the common electrode voltage generation circuit; 101 is the bias current generation module; 102 is the resistor module; 103 is the first operational amplifier module; 104 is the voltage division module; 105 is the second operational amplifier module; 106 is the voltage output module. Detailed Embodiments

[0011] In the following description, specific details such as specific system architectures, technologies, etc. are presented for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, those skilled in the art should clearly understand that the present application can also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to avoid unnecessary details from interfering with the description of the present application.

[0012] It should be understood that when used in the specification and the appended claims of the present application, the term "comprising" indicates the presence of the described features, wholes, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components, and / or their combinations.

[0013] It should also be understood that the term "and / or" used in the specification and the appended claims of the present application refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0014] As used in the specification and the appended claims of the present application, the term "if" can be interpreted as "when" or "once" or "in response to determining" or "in response to detecting" according to the context. Similarly, the phrase "if determined" or "if [the described condition or event] is detected" can be interpreted as meaning "once determined" or "in response to determining" or "once [the described condition or event] is detected" or "in response to detecting [the described condition or event]" according to the context.

[0015] In addition, in the description of the specification and the appended claims of the present application, the terms "first", "second", "third", etc. are only used for differentiating descriptions and cannot be understood as indicating or implying relative importance.

[0016] The reference to "one embodiment" or "some embodiments" or the like described in the specification of the present application means that a specific feature, structure, or characteristic described in connection with the embodiment is included in one or more embodiments of the present application. Thus, statements such as "in one embodiment", "in some embodiments", "in other some embodiments", "in still other embodiments", etc. that appear in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "comprising", "including", "having", and their variants all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0017] In electronic devices such as LCDs, VCOM is a key electrical parameter. The selection of its polarity is closely related to the driving method, power consumption optimization, and display performance, and directly affects the display quality and stability. To dynamically adjust VCOM to improve the trailing effect of high-refresh-rate images, it is necessary to set it to an output form with two sets of parameters, VCOMMIN and OFFSET, configured independently. Among them, VCOMMIN and OFFSET can adjust the output voltage by changing the internal register parameters. In the prior art, as Figure 1 shown, multiple operational amplifiers are usually used to generate positive and negative voltages through internal reference voltage operations. However, in this solution, multiple operational amplifiers (such as OP1, OP3, and VCOM_OP) all use the AVEE negative voltage as the reference ground. Since the AVEE negative voltage is usually generated by a switching power supply and has a large amount of noise, it causes a large amount of noise in VCOM.

[0018] Among them, GND represents the chip ground potential, AVEE represents the negative voltage potential, VDD represents the internal low positive voltage power supply, AVDD represents the internal high voltage power supply, VB represents the internal reference voltage, DAC_vcom_min represents the voltage that can be configured through a DAC (Digital-to-Analog Converter), and DAC_vcomoffset represents the bias voltage that can be configured through a DAC.

[0019] It should be noted that when the voltage output by the operational amplifier is positive and negative, the AVEE negative voltage needs to be used as the reference ground.

[0020] Exemplarily, taking Figure 1 as an example, the voltage vcom_min output by OP1 = R1*(1 / R1 + 1 / R2)*VB - DAC_vcom_min*R1 / R2. It can be seen from this that the voltage output by OP1 is positive and negative. Therefore, OP1 needs to use the AVEE negative voltage as the reference ground.

[0021] Based on the above problems, the common electrode voltage generation circuit provided in the embodiments of the present application includes a bias current generation module, a resistor module, a first operational amplifier module, a voltage division module, a second operational amplifier module, and a voltage output module. Among them, the bias current generation module can generate a bias current. When the bias current flows through the resistor module, a voltage drop, that is, a bias voltage, can be generated. Therefore, the bias voltage is equal to the product of the bias current and the resistance value of the resistor module. The first operational amplifier module outputs a second node voltage according to a reference voltage and a first node voltage, and the second node voltage is the sum of the reference voltage and the bias voltage. The voltage division module divides the received second node voltage and outputs a first voltage to the voltage output module. The second operational amplifier module outputs a second voltage to the voltage output module according to a configured voltage, and the voltage output module outputs a common electrode voltage according to the first voltage and the second voltage. It can be seen that in the process of outputting the common electrode voltage by the common electrode voltage generation circuit provided in the embodiments of the present application, since the second node voltage output by the first operational amplifier module is equal to the sum of the reference voltage and the bias voltage, and both the reference voltage and the bias voltage are positive voltages, the second node voltage is a positive voltage. This enables the devices in the first operational amplifier module to use GND as the reference ground, without using the AVEE negative voltage as the reference ground, thereby reducing the interference of the common electrode voltage by the AVEE negative voltage and effectively improving the noise suppression ability of the common electrode voltage against the AVEE negative voltage.

[0022] To illustrate the technical solutions described in the present application, the following will be described through specific embodiments.

[0023] Figure 2 The principle block diagram of a common electrode voltage generation circuit 10 provided in an embodiment of the present application is shown. Refer to Figure 2 As shown, the common electrode voltage generation circuit 10 includes a bias current generation module 101, a resistor module 102, a first operational amplifier module 103, a voltage division module 104, a second operational amplifier module 105, and a voltage output module 106. The first operational amplifier module 103 is electrically connected to the bias current generation module 101, the resistor module 102, and the voltage division module 104 respectively, and the voltage output module 106 is electrically connected to the voltage division module 104 and the second operational amplifier module 105 respectively.

[0024] Specifically, the bias current generation module 101 can generate a bias current IDAC_OFFSET. When the bias current IDAC_OFFSET flows through the resistor module 102, a voltage drop can be generated, that is, a bias voltage offset. Therefore, the bias voltage offset is equal to the product of the bias current IDAC_OFFSET and the resistance value of the resistor module 102. The first operational amplifier module 103 outputs a second node voltage according to the reference voltage VB and the first node voltage, and the second node voltage is the sum of the reference voltage VB and the bias voltage offset. The voltage division module 104 divides the received second node voltage and outputs a first voltage to the voltage output module 106. The second operational amplifier module 105 outputs a second voltage to the voltage output module 106 according to the configured voltage DAC_vcom_min, and the voltage output module 106 outputs the common electrode voltage VCOM according to the first voltage and the second voltage. It can be seen that in the process of outputting the common electrode voltage VCOM by the common electrode voltage generation circuit 10 provided in the embodiment of the present application, since the second node voltage output by the first operational amplifier module 103 is equal to the sum of the reference voltage VB and the bias voltage offset, and both the reference voltage VB and the bias voltage offset are positive voltages, the second node voltage is a positive voltage. This enables the devices in the first operational amplifier module 103 to use GND as the reference ground instead of the AVEE negative voltage as the reference ground, thereby reducing the interference of the common electrode voltage VCOM by the AVEE negative voltage and effectively improving the noise suppression ability of the common electrode voltage VCOM to the AVEE negative voltage.

[0025] It should be noted that the bias current generation module 101 is also connected to the ground, and the current flow direction of the bias current IDAC_OFFSET is from the first node to the ground, where the first node is the common terminal of the first operational amplifier module 103 and the resistor module 102. The configured voltage DAC_vcom_min can be a voltage configured by the DAC, and the bias voltage offset is the product of the bias current IDAC_OFFSET and the resistance value of the resistor module 102, that is, offset = IDAC_OFFSET*R 电阻 . Wherein, R 电阻 is the resistance value of the resistor module 102.

[0026] In an embodiment of the present application, as Figure 3 shown, the bias current generation module 101 includes a current source. The first end of the current source is electrically connected to the first operational amplifier module 103 and the resistor module 102 respectively, and the second end of the current source is grounded.

[0027] Specifically, the current source is mainly used to generate a stable bias current IDAC_OFFSET to provide a basic current signal for the resistor module 102. Specifically, the current source adopts a multi-group current mirror structure. By flexibly configuring the switching states of the current mirrors, different magnitudes of the bias current IDAC_OFFSET can be output. Since the bias voltage offset is equal to the product of the bias current IDAC_OFFSET and the resistance value of the resistor module 102, by adjusting the magnitude of the bias current IDAC_OFFSET, a voltage drop that meets the circuit requirements can be generated on the resistor module 102, thereby realizing the OFFSET voltage, and further providing the required bias voltage offset for the first operational amplifier module 103 to ensure the stable operation of the entire common electrode voltage generation circuit 10.

[0028] It should be noted that only one circuit structure of the bias current generation module 101 is shown in the embodiments provided in this application, which does not mean that only this one circuit structure can implement the function of the bias current generation module 101. Other circuit structures that can implement this function can also be substituted, and are not limited thereto.

[0029] In an embodiment of the present application, as Figure 3 shown, the first operational amplifier module 103 includes a first operational amplifier OP1. The first input terminal of the first operational amplifier OP1 is used to receive a reference voltage VB. The second input terminal of the first operational amplifier OP1 is electrically connected to both the bias current generation module 101 and the resistor module 102. The output terminal of the first operational amplifier OP1 is electrically connected to both the resistor module 102 and the voltage division module 104.

[0030] Specifically, the positive input terminal of the first operational amplifier OP1 serves as the first input terminal of the first operational amplifier OP1, and the negative input terminal of the first operational amplifier OP1 serves as the second input terminal of the first operational amplifier OP1. Through the differential input and negative feedback mechanism, the first operational amplifier OP1 precisely superimposes the reference voltage VB and the bias voltage offset to generate a stable second node voltage. Its positive input terminal receives the constant reference voltage VB, and the negative input terminal introduces the voltage drop generated by the bias current IDAC_OFFSET through the resistor network. By utilizing the "virtual short" characteristic of the operational amplifier, the voltages at both ends are forced to be equal, and thus a second node voltage equal to "reference voltage VB + bias voltage offset" is formed at the output terminal. This design not only isolates the mutual influence between the reference voltage VB source and the bias circuit, but also improves the voltage superposition accuracy through high-gain amplification and deep negative feedback, providing a low-impedance and high-stability voltage reference for the subsequent voltage division module 104 to ensure the accuracy of the common electrode voltage VCOM is not affected by load changes. In addition, since the second node voltage output by the first operational amplifier OP1 is a positive voltage, the first operational amplifier OP1 can use GND as the reference ground instead of the AVEE negative voltage as the reference ground, thereby reducing the number of operational amplifiers using the AVEE negative voltage as the reference ground and improving the anti-interference ability of the common electrode voltage VCOM against the AVEE negative voltage.

[0031] It should be noted that only one circuit structure of the first operational amplifier module 103 is shown in the embodiments provided in this application, which does not mean that only this one circuit structure can implement the function of the first operational amplifier module 103. Other circuit structures that can achieve this function can also be substituted, and are not limited thereto.

[0032] In an embodiment of the present application, as Figure 3 shown, the voltage division module 104 includes a first resistor R1 and a second resistor R2. The first end of the first resistor R1 is electrically connected to the first operational amplifier module 103 and the resistor module 102 respectively. The second end of the first resistor R1 is electrically connected to the first end of the second resistor R2 and the voltage output module 106 respectively. The second end of the second resistor R2 is grounded.

[0033] Specifically, the first resistor R1 and the second resistor R2 form a stable voltage division network through series voltage division to divide the second node voltage output by the first operational amplifier OP1. According to the voltage distribution principle of a series circuit, the second node voltage is distributed on the two resistors according to the resistance ratio, and finally a stable first voltage is generated at the connection node of the first resistor R1 and the second resistor R2. This first voltage serves as the voltage reference of the voltage output module 106, providing a stable reference for the final output of the common electrode voltage VCOM to ensure the accuracy and stability of the output voltage.

[0034] Exemplarily, the resistance values of the first resistor R1 and the second resistor R2 are not limited herein. For example, the resistance values of the first resistor R1 and the second resistor R2 can both be fixed resistance values or variable resistance values. In addition, in addition to using one first resistor R1 and one second resistor R2, the designer can also use other quantities of the first resistor R1 and the second resistor R2. For example, 2, 3, etc. of the first resistors R1 can be used for series-parallel connection, and 2, 3, etc. of the second resistors R2 can be used for series-parallel connection. This application Figure 3 only shows the circuit structure in which the voltage dividing module 104 includes a first resistor R1 with a fixed resistance value and a second resistor R2 with a fixed resistance value connected in series. Resistors with different quantities, different types, or different connection relationships can be used to replace the first resistor R1 and the second resistor R2, and their basic working principles are similar, so no further elaboration will be made here.

[0035] It should be noted that only one circuit structure of the voltage dividing module 104 is shown in the embodiments provided in this application, which does not mean that only this one circuit structure can achieve the function of the voltage dividing module 104. Other circuit structures that can achieve this function can also be replaced, and are not limited thereto.

[0036] In an embodiment of this application, as Figure 3 shown, the second operational amplifier module 105 includes a second operational amplifier OP2. The first input terminal of the second operational amplifier OP2 is used to receive the configuration voltage DAC_vcom_min, and the second input terminal of the second operational amplifier OP2 is electrically connected to the output terminal of the second operational amplifier OP2 and the voltage output module 106 respectively.

[0037] Specifically, the positive input terminal of the second operational amplifier OP2 serves as the first input terminal of the second operational amplifier OP2, and the negative input terminal of the second operational amplifier OP2 serves as the second input terminal of the second operational amplifier OP2. Since the negative input terminal and the output terminal of the second operational amplifier OP2 are connected, it is thus characterized that the second operational amplifier OP2 adopts the structure form of a voltage follower. Its core function is to stabilize the output configuration voltage DAC_vcom_min and provide a buffer drive with a high input impedance and a low output impedance for the voltage output module 106. Specifically, the second operational amplifier OP2 accesses the configuration voltage DAC_vcom_min to the positive input terminal, uses the "virtual short" characteristic to make the voltage of the negative input terminal equal to it, and at the same time relies on the direct connection between the output terminal and the negative input terminal to form a closed-loop feedback to ensure that the output voltage (the second voltage) accurately follows the change of the configuration voltage DAC_vcom_min. This design effectively isolates the mutual influence between the voltage output module 106 and the front-end configuration voltage DAC_vcom_min source, avoids voltage fluctuations caused by load changes, provides a stable and reliable reference signal for the generation of the common electrode voltage VCOM, and at the same time reduces the loss and interference in the signal transmission process, and improves the driving ability and stability of the overall circuit.

[0038] It should be noted that since the common electrode voltage VCOM output by the second operational amplifier OP2 is a positive voltage, the second operational amplifier OP2 uses GND as the reference ground.

[0039] It should be noted that only one circuit structure of the second operational amplifier module 105 is shown in the embodiments provided in this application, which does not mean that only this circuit structure can implement the function of the second operational amplifier module 105. Other circuit structures that can implement this function can also be substituted, and are not limited thereto.

[0040] In an embodiment of the present application, as Figure 3 shown, the resistor module 102 includes a third resistor R3. The first end of the third resistor R3 is electrically connected to the first operational amplifier module 103 and the bias current generation module 101 respectively, and the second end of the third resistor R3 is electrically connected to the first operational amplifier module 103 and the voltage division module 104 respectively.

[0041] Specifically, the third resistor R3 acts as a key current-voltage conversion element in the circuit, and realizes the conversion of the bias current IDAC_OFFSET to the bias voltage offset based on Ohm's law. One end of it is connected to the stable bias current IDAC_OFFSET output by the bias current generation module 101, and the other end is connected to the output end of the first operational amplifier OP1 and the voltage division module 104 to form a complete current loop. When the bias current IDAC_OFFSET flows through the third resistor R3, according to the quantitative relationship between voltage, current and resistance (i.e., voltage = current * resistance), a voltage drop proportional to the bias current IDAC_OFFSET is generated across the third resistor R3, and this voltage drop is the bias voltage offset. (The bias voltage offset can be changed by changing the magnitude of the bias current IDAC_OFFSET, so as to obtain the required bias voltage offset for the circuit). The generated bias voltage offset is used as a feedback signal to access the negative input terminal of the first operational amplifier OP1, and participates in the superposition operation of the reference voltage VB and the bias voltage offset. On the other hand, it provides a basic voltage signal for the voltage division module 104, directly affecting the generation of the final common electrode voltage VCOM, and ensuring that the entire circuit realizes precise voltage regulation.

[0042] It should be noted that only one circuit structure of the resistor module 102 is shown in the embodiments provided in this application, which does not mean that only this circuit structure can implement the function of the resistor module 102. Other circuit structures that can implement this function can also be substituted, and are not limited thereto.

[0043] In an embodiment of the present application, as Figure 3As shown, the output module includes a fourth resistor R4, a fifth resistor R5, and a third operational amplifier OP3. The first end of the fourth resistor R4 is electrically connected to the second operational amplifier module 105. The second end of the fourth resistor R4 is respectively electrically connected to the first end of the fifth resistor R5 and the second input terminal of the third operational amplifier OP3. The first input terminal of the third operational amplifier OP3 is electrically connected to the voltage division module 104. The output terminal of the third operational amplifier OP3 is electrically connected to the second end of the fifth resistor R5.

[0044] Specifically, the positive input terminal of the third operational amplifier OP3 serves as the first input terminal of the third operational amplifier OP3, and the negative input terminal of the third operational amplifier OP serves as the second input terminal of the third operational amplifier OP3. The fourth resistor R4, the fifth resistor R5, and the third operational amplifier OP3 together form a differential amplification circuit, whose function is to perform weighted synthesis on the first voltage output by the voltage division module 104 and the second voltage output by the second operational amplifier module 105 to generate an accurate common electrode voltage VCOM. Specifically, the positive input terminal of the third operational amplifier OP3 receives the first voltage from the voltage division module 104 as a reference signal, and the negative input terminal is connected to the second voltage output by the second operational amplifier OP2 through the fourth resistor R4, and forms a feedback loop with the output terminal through the fifth resistor R5. Utilizing the differential amplification characteristics of the operational amplifier, the output voltage satisfies the weighted superposition relationship based on the resistance ratio, thereby synthesizing the two voltage signals according to a preset ratio to obtain the final common electrode voltage VCOM. At the same time, the high input impedance of the third operational amplifier OP3 isolates the load effect of the previous-stage circuit, and the low output impedance provides a stable driving ability for the common electrode voltage VCOM, ensuring the accuracy and stability of the output voltage.

[0045] It should be noted that the resistance value of the fourth resistor R4 is the same as that of the first resistor R1, and the resistance value of the fifth resistor R5 is the same as that of the second resistor R2. By constructing a symmetric resistor network, accurate matching of the voltage division ratio and the feedback coefficient is achieved, thereby significantly improving the generation accuracy and stability of the common electrode voltage VCOM. Specifically, the first resistor R1 and the second resistor R2 in the voltage division module 104 divide the voltage of the second node according to the ratio of R2 / (R1 + R2), while the fourth resistor R4 and the fifth resistor R5 in the output module form a feedback network with the same ratio (R4 / (R4 + R5)), ensuring that the ratio relationship between the input voltage and the feedback voltage in the differential amplification process is strictly corresponding, fundamentally eliminating the voltage error caused by resistor mismatch. In addition, this symmetric design can effectively suppress the influence of common-mode interference (such as power supply fluctuations, temperature drift, etc.) on the output voltage. When environmental factors cause all resistors to change synchronously, the consistency of the voltage division ratio and the feedback coefficient can still be maintained, greatly improving the anti-interference ability of the circuit. At the same time, the standardized resistance value matching simplifies the circuit debugging process, reduces the dependence on high-precision resistors, and significantly improves the production efficiency and cost controllability while ensuring the voltage accuracy, especially suitable for application scenarios such as display driving circuits with strict requirements for voltage stability.

[0046] It should be noted that, since the common electrode voltage VCOM output by the third operational amplifier OP3 is positive and negative, the third operational amplifier OP3 uses the AVEE negative voltage as the reference ground.

[0047] In an embodiment of the present application, as Figure 3 shown, the output module further includes a fourth operational amplifier VCOM_OP. The first input terminal of the fourth operational amplifier VCOM_OP is electrically connected to the output terminal of the third operational amplifier OP3 and the second terminal of the fifth resistor R5 respectively. The second input terminal of the fourth operational amplifier VCOM_OP is electrically connected to the output terminal of the fourth operational amplifier VCOM_OP.

[0048] Specifically, the positive input terminal of the fourth operational amplifier VCOM_OP serves as the first input terminal of the fourth operational amplifier VCOM_OP, and the negative input terminal of the fourth operational amplifier VCOM_OP serves as the second input terminal of the fourth operational amplifier VCOM_OP. Since the negative input terminal and the output terminal of the fourth operational amplifier VCOM_OP are connected, it is thus characterized that the fourth operational amplifier VCOM_OP adopts the structure form of a voltage follower. Its positive input terminal is connected to the output terminal of the third operational amplifier OP3, and the negative input terminal is directly short-circuited with the output terminal to form deep negative feedback. The main function is to realize signal buffering and isolation. Specifically, the fourth operational amplifier VCOM_OP utilizes the high input impedance characteristic to avoid generating a load effect on the front-stage differential amplification circuit, ensuring that the voltage signal output by the third operational amplifier OP3 is not affected by the subsequent circuit. At the same time, through the low output impedance characteristic, the driving ability for the common electrode voltage VCOM is enhanced, enabling it to stably drive various loads (such as capacitive or inductive loads). In addition, the isolation effect of the voltage follower can also effectively suppress the influence of external interference on the output voltage, ensuring the stability and reliability of the common electrode voltage VCOM, especially suitable for scenarios that require driving large loads or have high requirements for voltage accuracy.

[0049] It should be noted that, since the common electrode voltage VCOM output by the fourth operational amplifier VCOM_OP is positive and negative, the fourth operational amplifier VCOM_OP uses the AVEE negative voltage as the reference ground.

[0050] It should be noted that only one circuit structure of the voltage output module 106 is shown in the embodiments provided in the present application, which does not mean that there is only this one circuit structure that can realize the function of the voltage output module 106. Other circuit structures that can realize this function can also be replaced, and are not limited thereto.

[0051] It should be noted that in the prior art, all use the internal reference voltage VB to realize positive and negative voltages through calculation Figure 1 For the circuit shown, the VCOM obtained after calculation = , in this way, different VCOM voltage outputs can be obtained by changing the values of two DACs, and independent configuration of vcom_min and vcomoffset can be achieved. Among them, k1, k2, and k3 are all determined by the ratio relationship between resistors. This implementation method requires precise matching among multiple resistors (such as R1, R2, R3~R7), resulting in extremely complex circuit design. However, the present application adopts the form of combining a reference voltage VB and a reference current, and the obtained VCOM = , from which it can be seen that different VCOM voltage outputs can be obtained by changing the values of IDAC_OFFSET and DAC_vcom_min, and independent configuration of vcom_min and vcomoffset can also be achieved. That is, the present application realizes the independently configurable output of VCOM and its offset voltage offset through the combination of a variable current source, a variable voltage reference, and the characteristics of multiple operational amplifiers. In addition, the first resistor R1, the second resistor R2, the third resistor R, the fourth resistor R4, and the fifth resistor R5 in the common electrode voltage generation circuit 10 of the present application do not need to be precisely matched, reducing the requirement for the number of resistor matches, thereby greatly reducing the circuit design difficulty and saving chip area at the same time.

[0052] The present application also discloses a power supply device. The power supply device adopts the above-mentioned common electrode voltage generation circuit 10, which can enable the power supply device to exhibit the advantages of low ripple, high anti-interference ability, and strong load driving ability when driving the common electrode voltage VCOM (such as the VCOM of a display screen). It can also enable the power supply device to have the dual advantages of high performance and low cost, and is particularly suitable for fields such as display and industrial control that have high requirements for voltage accuracy and stability.

[0053] The present application also discloses an electronic device (such as an LCD or other display device), including the above-mentioned power supply device. By adopting the above-mentioned power supply device, the electronic device can significantly improve the uniformity and color reproduction of the display screen by virtue of the high-precision and high-stability design of the common electrode voltage generation circuit 10. Specifically, the power supply device generates a stable common electrode voltage VCOM by combining the reference voltage VB and the reference current, effectively eliminating common problems such as flicker, color difference, and brightness unevenness on the LCD screen; at the same time, the ability of the common electrode voltage generation circuit 10 to suppress the negative voltage interference of AVEE can reduce the influence of power supply noise on the display driving signal, and the picture can be kept stable even in a complex electromagnetic environment. In addition, the strong load driving ability of the power supply device can adapt to the capacitive load characteristics of the LCD screen, avoiding the VCOM voltage drift caused by load changes and further improving the reliability of the display image quality. This design enables the electronic device to achieve higher display performance while taking into account low power consumption and low cost, and is particularly suitable for scenarios with strict requirements for picture quality such as high-end LCD TVs and professional monitors.

[0054] Since the processing and functions implemented by the power supply device and the electronic device in this embodiment are basically corresponding to the embodiments, principles and examples of the aforementioned common electrode voltage generation circuit, for the details not described in the description of this embodiment, reference can be made to the relevant descriptions in the aforementioned embodiments, and no further elaboration will be provided here.

[0055] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements 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 the present application, and should all be included in the protection scope of the present application.

Claims

1. A common electrode voltage generating circuit, characterized in that, It includes a bias current generation module, a resistor module, a first operational amplifier module, a voltage division module, a second operational amplifier module, and a voltage output module. The first operational amplifier module is electrically connected to the bias current generation module, the resistor module, and the voltage division module respectively. The voltage output module is electrically connected to the voltage division module and the second operational amplifier module respectively. The bias current generation module is used to generate a bias current; the resistor module is used to generate a bias voltage according to the bias current; the first operational amplifier module is used to output a second node voltage according to a reference voltage and a first node voltage. Wherein, the first node voltage is the voltage at the common terminal of the first operational amplifier module and the bias current generation module, and the second node voltage is the voltage at the common terminal of the first operational amplifier module and the voltage division module. The second node voltage is the sum of the reference voltage and the bias voltage; the voltage division module is used to output a first voltage to the voltage output module according to the second node voltage; the second operational amplifier module is used to output a second voltage to the voltage output module according to a configuration voltage; the voltage output module is used to output a common electrode voltage according to the first voltage and the second voltage.

2. The common electrode voltage generation circuit according to claim 1, wherein The bias current generation module includes a current source. The first end of the current source is electrically connected to the first operational amplifier module and the resistor module respectively, and the second end of the current source is grounded.

3. The common electrode voltage generation circuit according to claim 1, wherein The first operational amplifier module includes a first operational amplifier. The first input terminal of the first operational amplifier is used to receive the reference voltage. The second input terminal of the first operational amplifier is electrically connected to the bias current generation module and the resistor module respectively. The output terminal of the first operational amplifier is electrically connected to the resistor module and the voltage division module respectively.

4. The common electrode voltage generation circuit according to claim 1, wherein The voltage division module includes a first resistor and a second resistor. The first end of the first resistor is electrically connected to the first operational amplifier module and the resistor module respectively. The second end of the first resistor is electrically connected to the first end of the second resistor and the voltage output module respectively. The second end of the second resistor is grounded.

5. The common electrode voltage generation circuit according to claim 1, characterized in that, The second operational amplifier module includes a second operational amplifier. The first input terminal of the second operational amplifier is used to receive the configuration voltage. The second input terminal of the second operational amplifier is electrically connected to the output terminal of the second operational amplifier and the voltage output module respectively.

6. The common electrode voltage generating circuit according to claim 1, wherein The resistor module includes a third resistor. The first end of the third resistor is electrically connected to the first operational amplifier module and the bias current generation module respectively. The second end of the third resistor is electrically connected to the first operational amplifier module and the voltage division module respectively.

7. The common electrode voltage generation circuit according to claim 1, wherein The output module includes a fourth resistor, a fifth resistor, and a third operational amplifier. The first end of the fourth resistor is electrically connected to the second operational amplifier module. The second end of the fourth resistor is electrically connected to the first end of the fifth resistor and the second input terminal of the third operational amplifier respectively. The first input terminal of the third operational amplifier is electrically connected to the voltage division module. The output terminal of the third operational amplifier is electrically connected to the second end of the fifth resistor.

8. The common electrode voltage generation circuit according to claim 7, wherein The output module further includes a fourth operational amplifier. A first input terminal of the fourth operational amplifier is electrically connected to an output terminal of the third operational amplifier and a second terminal of the fifth resistor respectively. A second input terminal of the fourth operational amplifier is electrically connected to an output terminal of the fourth operational amplifier.

9. A power supply device, characterized in that, It includes the common electrode voltage generation circuit according to any one of claims 1-8.

10. An electronic device, characterized in that, It includes the power supply device according to claim 9.

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