Voltage correction circuit and display device

Abstract

The present invention discloses a voltage correction circuit and a display device. The voltage correction circuit includes: a correction module and a driving module connected in series between the output end and the control end of the power supply circuit; wherein the correction module includes: an amplification unit, a multiplication correction unit, and a signal correction unit; the multiplication correction unit is connected between the input end and the output end of the amplification unit; the multiplication correction unit is used to adjust the amplification factor of the amplification unit; the signal correction unit is electrically connected to the input end of the amplification unit; the signal correction unit is used to adjust a first adjustment signal transmitted to the input end of the amplification unit; the amplification unit is electrically connected to the driving module; the amplification unit generates a correction signal in response to the first adjustment signal and the amplification factor, so that the driving module controls the output voltage of the power supply circuit. The embodiments of the present invention can improve the accuracy of the output voltage of the power supply circuit, thereby improving the display effect of the display device.

Description

Technical Field

[0001] The present invention relates to the field of display technology, and in particular to a voltage correction circuit and a display device. Background Art

[0002] In existing display devices, the output voltage range of the power supply circuit in the driver chip is relatively wide. Due to limitations such as the voltage reference or bandwidth in the power supply loop, the output voltage of the power supply circuit has deviations. In particular, when the output voltage reaches near the maximum or minimum value of the output voltage range, the output voltage accuracy deviation is relatively large, which can easily cause problems such as display screen abnormalities. Summary of the Invention

[0003] The present invention provides a voltage correction circuit and a display device, so as to improve the accuracy of the output voltage of a power supply circuit, thereby improving the display effect of the display device.

[0004] To achieve the above technical objectives, the embodiments of the present invention provide the following technical solutions:

[0005] A voltage correction circuit comprises: a correction module and a driving module connected in series between an output terminal and a control terminal of a power supply circuit;

[0006] Wherein, the correction module includes: an amplification unit, a multiplication correction unit and a signal correction unit;

[0007] The magnification correction unit is connected between the input end and the output end of the amplifying unit; the magnification correction unit is used to adjust the amplification factor of the amplifying unit;

[0008] The signal correction unit is electrically connected to the input end of the amplifying unit; the signal correction unit is used to adjust the first adjustment signal transmitted to the input end of the amplifying unit;

[0009] The amplifying unit is electrically connected to the driving module; the amplifying unit generates a correction signal in response to the first adjustment signal and the amplification factor, so that the driving module controls the output voltage of the power supply circuit.

[0010] Optionally, the correction module also includes: a control unit, which is electrically connected to the output end of the power supply circuit, the multiplier correction unit and the signal correction unit respectively; the control unit is used to control the multiplier correction unit to adjust the amplification factor of the amplification unit according to the output voltage of the power supply circuit, and to control the signal correction unit to adjust the first adjustment signal according to the output voltage of the power supply circuit.

[0011] Optionally, the magnification correction unit has an adjustable impedance; the magnification correction unit is used to adjust the amplification factor of the amplification unit by adjusting its impedance;

[0012] The signal correction unit has an adjustable impedance; the signal correction unit is used to adjust the first adjustment signal transmitted to the input end of the amplification unit by adjusting its impedance.

[0013] Optionally, the output voltage of the power supply circuit is a positive value; when the output voltage of the power supply circuit exceeds a first threshold voltage, the impedance of the multiplication correction unit is adjusted;

[0014] When the output voltage of the power supply circuit is lower than a second threshold voltage, adjusting the impedance of the signal correction unit;

[0015] The first threshold voltage is greater than the second threshold voltage.

[0016] Optionally, the multiplication correction unit includes: a first potentiometer; a first end of the first potentiometer is electrically connected to the input end of the amplifying unit, and a sliding end of the first potentiometer is electrically connected to the output end of the amplifying unit;

[0017] Preferably, the multiplication correction unit further includes: a first resistor; the first resistor and the first potentiometer are connected in series between the input end and the output end of the amplification unit.

[0018] Optionally, the signal correction unit includes: a second potentiometer and a second resistor; the first end of the second potentiometer is connected to the first reference signal, the second end of the second potentiometer is grounded, the sliding end of the second potentiometer is electrically connected to the first end of the second resistor, and the second end of the second resistor is electrically connected to the input end of the amplification unit.

[0019] Optionally, the amplifying unit includes: a first amplifier and a third resistor;

[0020] The first input end of the first amplifier serves as the input end of the amplifying unit, the second input end of the first amplifier is electrically connected to the first end of the third resistor, the second end of the third resistor is grounded, and the output end of the first amplifier serves as the output end of the amplifying unit.

[0021] Optionally, the correction module further includes: a voltage dividing unit; the voltage correction circuit further includes: a sampling module;

[0022] The sampling module is electrically connected to the output end of the power supply circuit; the sampling module is used to collect the output voltage of the power supply circuit and generate a sampling signal according to the output voltage;

[0023] The voltage divider unit is electrically connected to the input end of the amplifying unit and the sampling module respectively; the voltage divider unit is used to generate a second adjustment signal according to the sampling signal; the amplifying unit generates a correction signal in response to the first adjustment signal, the amplification factor and the second adjustment signal;

[0024] Preferably, the voltage dividing unit includes: a fourth resistor; a first end of the fourth resistor is electrically connected to the sampling module, and a second end of the fourth resistor is electrically connected to the input end of the amplifying unit;

[0025] Preferably, the sampling module includes: a fifth resistor and a sixth resistor; a first end of the fifth resistor is electrically connected to the output end of the power supply circuit; a second end of the fifth resistor is electrically connected to the first end of the sixth resistor and serves as the output end of the sampling module; and a second end of the sixth resistor is grounded.

[0026] Preferably, the sampling module further includes: an error amplifier; a first input terminal of the error amplifier is electrically connected to the second terminal of the fifth resistor, a second terminal of the error amplifier is connected to a second reference signal, and an output terminal of the error amplifier serves as an output terminal of the sampling module;

[0027] Preferably, the sampling module further includes: a voltage follower; the input end of the voltage follower is electrically connected to the output end of the error amplifier, and the output end of the voltage follower serves as the output end of the sampling module.

[0028] Optionally, the driving module includes: a comparator; the power supply circuit includes: a power switching device;

[0029] The first input terminal of the comparator is electrically connected to the output terminal of the correction module, the second input terminal of the comparator is connected to the triangular wave signal, and the output terminal of the comparator is electrically connected to the control terminal of the power switching device;

[0030] The control end of the power switch device serves as the control end of the power circuit, and the power switch device is used to control the output of the power circuit according to the signal at its control end.

[0031] Correspondingly, an embodiment of the present invention further provides a display device, comprising a power supply circuit and a voltage correction circuit as provided in any embodiment of the present invention.

[0032] The voltage correction circuit provided in an embodiment of the present invention comprises a correction module and a driving module. The correction module includes an amplification unit, a multiplication correction unit, and a signal correction unit. The multiplication correction unit adjusts the correction signal output by the correction module by adjusting the amplification factor of the amplification unit. The multiplication correction unit has a strong adjustment capability and is more suitable for situations where the output voltage amplitude of the power supply circuit is large and / or the output voltage differs significantly from its theoretical value. A smaller adjustment amount can provide a more significant adjustment effect on the correction signal, thereby enabling the correction module to respond quickly to changes in the output voltage. The signal correction unit adjusts the correction signal by adjusting the magnitude of a first adjustment signal. Compared with the multiplication correction unit, the signal correction unit can achieve more precise adjustment of the correction signal. The signal correction unit is more suitable for situations where the output voltage amplitude is small and / or the output voltage differs slightly from its theoretical value. This allows for fine adjustment of the correction signal, avoids overshoot of the correction signal caused by the large adjustment capability of the multiplication correction unit, and ensures the stability of the adjustment. In this embodiment of the present invention, the correction unit to be activated can be selected based on the output condition of the power supply circuit, or the ratio of the two correction units can be adjusted to achieve a balance between the speed and accuracy of the power supply circuit output voltage adjustment. Therefore, compared with the prior art, the embodiments of the present invention can improve the accuracy of the output voltage of the power circuit, stabilize the power signal transmitted to the display device, and thus improve the display effect of the display device.

[0033] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present invention, nor is it intended to limit the scope of the present invention. Other features of the present invention will become readily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0035] Figure 1 1 is a schematic structural diagram of a voltage correction circuit provided by an embodiment of the present invention;

[0036] Figure 2 is a structural diagram of another voltage correction circuit provided by an embodiment of the present invention;

[0037] Figure 3 1 is a schematic structural diagram of another voltage correction circuit provided by an embodiment of the present invention;

[0038] Figure 4 1 is a schematic structural diagram of another voltage correction circuit provided by an embodiment of the present invention;

[0039] Figure 5 This is a structural diagram of another voltage correction circuit provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0040] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0041] It should be noted that the terms "first," "second," and the like in the description and claims of the present invention and the accompanying drawings are used to distinguish similar items and are not necessarily used to describe a particular order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate, such that the embodiments of the present invention described herein can be implemented in sequences other than those illustrated or described herein. Furthermore, the terms "including," "having," and any variations thereof are intended to cover non-exclusive inclusions.

[0042] As described in the background art, in existing display devices, the output voltage of the power supply circuit in the driver chip has a deviation. Taking the reference voltage signal used to initialize the gate of the driver transistor and / or the anode of the light-emitting device in the pixel circuit as an example, its value is usually negative. In order to verify the output deviation of the power supply circuit, the inventors compared the measured and theoretical values of the reference voltage signal within its entire output voltage range (e.g., -7.5-0V) and calculated the deviation. The test results show that the measured value of the reference voltage signal has a certain deviation from the theoretical value throughout the output range, and the deviation is larger when the output voltage is close to 0V and close to -7.5V. Specifically, when the corresponding theoretical value exceeds -2.5V and is lower than -7.1V, the deviation between the measured value and the theoretical value of the power supply circuit output voltage exceeds 1%; when the corresponding theoretical value is between -7.1 and -2.5V, the deviation between the measured value and the theoretical value of the power supply circuit output voltage is between 0.7% and 1%.

[0043] Furthermore, taking the pixel circuits in display devices composed of P-type transistors as an example, the voltage range of the high-level signal used to turn off the P-type transistor is typically 5-15V, with a typical value of approximately 7V, but in practice it may reach 10V or even 12V. Within its output voltage range, the high-level signal also exhibits a pattern of large voltage deviations near the upper and lower limits, and smaller voltage deviations in the middle.

[0044] The above research shows that there is deviation in the output voltage of the power circuit in the driver chip. Especially when the output voltage is close to the upper and lower limits of the output voltage range, the deviation is particularly obvious, which will affect the display effect of the display device.

[0045] To solve the above problem, an embodiment of the present invention provides a voltage correction circuit to implement feedback regulation of the output voltage of a power supply circuit. Figure 1 Schematic diagram of a voltage correction circuit provided by an embodiment of the present invention. Figure 1 The voltage correction circuit 100 includes a correction module 20 and a driving module 30 connected in series between the output terminal and the control terminal of the power supply circuit 200. The correction module 20 is used to generate a correction signal; the driving module 30 is used to control the output voltage Vo of the power supply circuit 200 according to the correction signal.

[0046] Specifically, the correction module 20 includes: an amplification unit 210, a magnification correction unit 231, and a signal correction unit 232. The magnification correction unit 231 is connected between the input and output terminals of the amplification unit 210; the magnification correction unit 231 is used to adjust the amplification factor of the amplification unit 210. The signal correction unit 232 is electrically connected to the input terminal of the amplification unit 210; the signal correction unit 232 is used to adjust the first adjustment signal transmitted to the input terminal of the amplification unit 210. The amplification unit 210 is electrically connected to the driving module 30; the amplification unit 210 generates a correction signal in response to the first adjustment signal and the amplification factor, so that the driving module 30 controls the output voltage Vo of the power supply circuit 200.

[0047] The output of amplifier unit 210 serves as the output of correction module 20. Amplifier unit 210 is configured to output a correction signal. The output of amplifier unit 210 is controlled by both multiplier correction unit 231 and signal correction unit 232. Specifically, when adjusting the amplification factor of amplifier unit 210, a relatively small adjustment amount can significantly impact the correction signal. When adjusting the input signal of amplifier unit 210, a relatively large adjustment amount is required to significantly impact the correction signal. Therefore, when the actual output voltage differs slightly from the theoretical value, voltage correction can be performed more by adjusting the first adjustment signal connected to the input of amplifier unit 210 by signal correction unit 232. When the actual output voltage differs significantly from the theoretical value, voltage correction can be performed more by adjusting the amplification factor of amplifier unit 210 by multiplier correction unit 321. This balances the adjustment methods for output voltage Vo under various deviation conditions, ensuring that the desired adjustment effect can be achieved with a relatively small adjustment amount in each condition. Voltage overshoot caused by adjusting the amplification factor is minimized, ensuring that the output voltage changes as linearly as possible.

[0048] The voltage correction circuit 100 provided in the embodiment of the present invention is provided with a correction module 20 and a driving module 30. The correction module 20 includes an amplification unit 210, a multiplication correction unit 231, and a signal correction unit 232. The multiplication correction unit 231 adjusts the correction signal output by the correction module 20 by adjusting the amplification factor of the amplification unit 210. The multiplication correction unit 231 has a strong adjustment capability and is more suitable for situations where the amplitude of the output voltage Vo of the power supply circuit 200 is large and / or the output voltage Vo differs significantly from its theoretical value. A relatively small adjustment amount can provide a more significant adjustment effect to the correction signal, thereby enabling the correction module 20 to respond quickly to changes in the output voltage Vo. The signal correction unit 232 adjusts the correction signal by adjusting the magnitude of the first adjustment signal. Compared with the multiplication correction unit 231, the signal correction unit 232 can achieve more precise adjustment of the correction signal. The signal correction unit 232 is more suitable for situations where the amplitude of the output voltage Vo is small, and / or the output voltage Vo differs little from its theoretical value, so as to achieve fine adjustment of the correction signal, avoid overshoot of the correction signal caused by the large adjustment capacity of the multiplication correction unit 231, and ensure the stability of the adjustment. The embodiment of the present invention can select the correction unit that needs to work or adjust the action ratio of the two correction units according to the output situation of the power supply circuit 200, so as to take into account the speed and accuracy of the output voltage adjustment of the power supply circuit. Therefore, compared with the prior art, the embodiment of the present invention can improve the accuracy of the output voltage of the power supply circuit, stabilize the power signal transmitted to the display device, and thus improve the display effect of the display device.

[0049] Based on the above embodiments, optionally, both the multiplication correction unit 231 and the signal correction unit 232 have adjustable impedances. The two correction units implement adjustment and correction as follows: the multiplication correction unit 231 adjusts the amplification factor of the amplification unit 210 by adjusting its own impedance. The signal correction unit 232 adjusts the first adjustment signal transmitted to the input end of the amplification unit 210 by adjusting its own impedance.

[0050] Figure 2 FIG is a schematic diagram of another voltage correction circuit provided by an embodiment of the present invention. Figure 2Based on the above embodiments, the correction module 20 optionally further includes a control unit 240 electrically connected to the output terminal of the power circuit 200, the multiplication correction unit 231, and the signal correction unit 232. The control unit 240 is configured to control the multiplication correction unit 231 to adjust the amplification factor of the amplification unit 210 according to the output voltage Vo of the power circuit 200, and to control the signal correction unit 232 to adjust the first adjustment signal according to the output voltage Vo of the power circuit 200. Specifically, the control unit 240 adjusts the impedance of the multiplication correction unit 231 and the signal correction unit 232 according to the output voltage Vo. In this embodiment, a control unit 240 is provided to directly adjust the impedance of the multiplication correction unit 231 and the signal correction unit 232 according to the output signal Vo, which is equivalent to providing two correction branches, namely the control unit 240-multiplication correction unit 231-amplification unit 210, and the control unit 240-signal correction unit 232-amplification unit 210, for feedback adjustment of the correction signal according to the output signal Vo, thereby providing conditions for real-time adjustment of the two correction units during the operation of the power supply circuit 200.

[0051] Continue to see Figure 2 Based on the above embodiments, the correction module 20 optionally further includes a voltage divider 220, and the voltage correction circuit 100 further includes a sampling module 10. The sampling module 10 is electrically connected to the output terminal of the power supply circuit 200. The sampling module 10 is configured to collect the output voltage Vo of the power supply circuit 200 and generate a sampling signal based on the output voltage Vo. The voltage divider 220 is electrically connected to the input terminal of the amplification unit 210 and the sampling module 10, respectively. The voltage divider 210 is configured to generate a second adjustment signal based on the sampling signal. The amplification unit 210 generates the correction signal in response to the first adjustment signal, the amplification factor, and the second adjustment signal.

[0052] This configuration is equivalent to adding a correction branch to the voltage correction circuit 100: a feedback adjustment branch consisting of the sampling module 10, the voltage divider unit 220, and the amplifier unit 210. Similar to the first adjustment signal, the second adjustment signal output by the voltage divider unit 220 also acts on the input of the amplifier unit 210, thereby controlling the output of the amplifier unit 210 and achieving more precise adjustment of the correction signal. This correction branch cooperates with the correction branches of the two correction units, allowing the first adjustment signal, the amplification factor, and the second adjustment signal to act simultaneously on the amplifier unit 210 to adjust the correction signal, thereby increasing the flexibility and reliability of the power correction circuit 100. The adjustment amount of the relevant parameters in the amplifier unit 210 by the voltage divider unit 220 and the two correction units can be adjusted based on the difference between the actual output voltage and the theoretical value, thereby achieving precise adjustment of the output voltage Vo across the entire voltage output range. Furthermore, even if one correction branch fails, the other correction branches can still provide feedback adjustment of the output voltage Vo, effectively ensuring the reliability of the power correction circuit 100.

[0053] Exemplarily, the voltage divider unit 220 is an impedance unit that can convert the sampling signal output by the sampling module 10 into a current signal and transmit it to the amplifying unit 210. The second regulated signal transmitted by the voltage divider unit 220 to the input end of the amplifying unit 210 is denoted as I1. Furthermore, the signal correction unit 232 can receive a reference voltage signal and, after impedance adjustment, convert the reference voltage signal into a current signal and transmit it to the amplifying unit 210. The first regulated signal transmitted by the signal correction unit 232 to the input end of the amplifying unit 210 is denoted as I2. The impedance of the multiplication correction unit 231 is denoted as R01. Therefore, the current flowing through the multiplication correction unit 231 is actually the sum of the second regulated signal and the first regulated signal. The correction signal (denoted as Vc) output by the amplifying unit 210 is: Vc = R01*(I1+I2). Thus, when the impedance of the voltage divider unit 220 is fixed, if the amplitude of the output voltage Vo is large and / or the output voltage Vo differs greatly from its theoretical value, the correction signal Vc can be adjusted by adjusting the impedance of the multiplier correction unit 231, so that the correction module 20 responds quickly to the change of the output voltage Vo, and a more obvious correction signal Vc adjustment effect is achieved through a smaller impedance adjustment amount; if the amplitude of the output voltage Vo is small and / or the output voltage Vo differs little from its theoretical value, the correction signal Vc can be adjusted by adjusting the impedance of the signal correction unit 232 to achieve fine adjustment of the correction signal Vc, thereby avoiding overshoot of the correction signal Vc caused by the impedance change of the multiplier correction unit 231. In addition, the voltage divider unit 220 can also be set as an impedance unit with adjustable impedance. In this way, by adjusting the impedance of the voltage divider unit 220, the participation (adjustment ratio) of the adjustment branch where the voltage divider unit 220 is located in this adjustment process can be adjusted, thereby improving the flexibility of the adjustment process. Among them, the impedance adjustment of the voltage divider unit 220 can also be achieved based on the output voltage Vo.

[0054] On the basis of the above embodiments, based on the output characteristics of the power supply circuit 200 and the adjustment characteristics of the correction module 20, the voltage correction circuit 100 may optionally be applied in the following ways, including but not limited to:

[0055] In one embodiment, optionally, before the power supply circuit 200 is put into operation, the impedance of at least one of the multiple correction unit 231 and the signal correction unit 232 is first adjusted when the output voltage Vo corresponds to the two ends of the theoretical output voltage range. When the deviation of the output voltage Vo from the theoretical value is within the allowable range throughout the entire output voltage range, the adjustment is stopped, and the operating impedance of the multiple correction unit 231 and the signal correction unit 232 is determined. Subsequently, during the use of the power supply circuit 200, the impedance of the multiple correction unit 231 and the signal correction unit 232 remains unchanged at the above operating impedance, and feedback adjustment is performed only through the correction branch where the voltage divider unit 220 is located. This configuration ensures that the multiple correction unit 231 and the signal correction unit 232 only need to operate before the power supply circuit 200 is put into operation, eliminating the need for repeated adjustment during the use of the power supply circuit 200. This can simplify the control logic of the power supply circuit 200 and reduce the operating power consumption of the power supply circuit 200.

[0056] In another embodiment, optionally, during the operation of the power supply circuit 200, the correction branch where the voltage divider unit 220 is located can be controlled to operate, as well as the correction branch where at least one correction unit among the multiple correction unit 231 and the signal correction unit 232 is located can be controlled to operate, thereby achieving at least two-fold feedback adjustment of the output voltage Vo, thereby improving the correction accuracy and the response speed of the correction circuit.

[0057] In another embodiment, multiple feedback regulation can be optionally implemented with all correction branches operating when the output voltage Vo corresponds to the upper and lower limits of the theoretical output voltage range; and when the output voltage Vo corresponds to the middle part of the theoretical output voltage range, only the correction branch where the voltage divider unit 220 is located can be used for regulation. In this way, multiple adjustments are implemented when the output voltage Vo deviates significantly from the theoretical value, and a single correction branch is used for regulation when the output voltage Vo deviates slightly from the theoretical value, so that the regulation process conforms to the variation pattern of the deviation between the output voltage Vo and the theoretical value.

[0058] To sum up, the voltage correction circuit 100 can optimize the first adjustment signal transmitted to the amplification unit 210 and the amplification factor of the amplification unit 210 on the basis of realizing feedback adjustment of the output voltage Vo, effectively improving the accuracy of the output voltage near the maximum and minimum values, so that the deviation of the output voltage Vo from the theoretical value in the full voltage range tends to be consistent, thereby improving the accuracy and linearity of the output voltage Vo and avoiding the problem of large voltage error at both ends.

[0059] Based on the above embodiments, optionally, taking the output voltage Vo of the power supply circuit 200 as a positive value as an example, when the multiplier correction unit 231 and the signal correction unit 232 are enabled, when the output voltage Vo exceeds a first threshold voltage, the control unit 240 adjusts the impedance of the multiplier correction unit 231 to adjust the amplification factor of the amplifier unit 210 so that the output voltage Vo reaches the theoretical value as quickly as possible. When the output voltage Vo is lower than a second threshold voltage, the control unit 240 adjusts the impedance of the signal correction unit 232 to adjust the first adjustment signal transmitted to the input terminal of the amplifier unit 210 to avoid overshoot of the correction voltage caused by the multiplier adjustment. The first threshold voltage is greater than the second threshold voltage.

[0060] The above embodiment is described using the example of a consistently positive output voltage Vo, but this is not intended to limit the present invention. In other embodiments, if the theoretical output voltage range of the output voltage Vo is partially or entirely negative, the correction unit for adjusting the correction signal may be selected based on the relationship between the absolute value of the output voltage and the first and second threshold voltages.

[0061] Taking the example of enabling the multiplier correction unit 231 and the signal correction unit 232 before the power supply circuit 200 is put into use, specifically, still assuming that the output voltage Vo is a positive voltage for explanation, first, when the output voltage Vo corresponds to the theoretical output voltage upper limit, the impedance of the multiplier correction unit 231 can be adjusted so that the deviation between the current output voltage and the theoretical output voltage upper limit is within the allowable range, the impedance of the multiplier correction unit 231 is fixed at the current impedance, and a test is conducted to determine whether the deviation of the output voltage Vo in the full voltage range is within the allowable range under the current impedance. If the accuracy of the output voltage Vo near the theoretical voltage lower limit still does not meet the requirements, the output voltage Vo can be adjusted to a position corresponding to the theoretical output voltage lower limit, the impedance of the signal correction unit 232 can be adjusted so that the deviation between the current output voltage and the theoretical output voltage lower limit is within the allowable range, the impedance of the signal correction unit 232 is fixed at the current impedance, and a test is conducted to determine whether the deviation of the output voltage Vo in the full voltage range is within the allowable range under the current impedance. The adjustment is repeated for multiple times until the deviation of the output voltage Vo in the full voltage range is within the allowable range, and the operating impedance of the multiple correction unit 231 and the signal correction unit 232 can be determined.

[0062] The above embodiments exemplify the functional units and modules of the voltage correction circuit. The specific structures that each functional unit and module may have are described below, but this does not limit the present invention.

[0063] Figure 3 This is a schematic diagram of the structure of another voltage correction circuit provided by an embodiment of the present invention. Figure 3In one embodiment, optionally, the amplifying unit 210 includes: a first amplifier OP1 and a third resistor R3; the first input end (reverse input end) of the first amplifier OP1 serves as the input end of the amplifying unit 210, the second input end (positive input end) of the first amplifier OP1 is electrically connected to the first end of the third resistor R3, the second end of the third resistor R3 is grounded, and the output end of the first amplifier OP1 serves as the output end of the amplifying unit 210.

[0064] Continue to see Figure 3 Based on the above embodiments, the voltage divider unit 220 optionally includes a fourth resistor R4; a first end of the fourth resistor R4 is electrically connected to the sampling module 10; and a second end of the fourth resistor R4 is electrically connected to the input of the amplification unit 210, that is, to the first input of the first amplifier OP1. In this way, the sampling signal (voltage signal) generated by the sampling module 10 after collecting the output voltage Vo can be converted into a second regulated signal (current signal) after passing through the fourth resistor R4.

[0065] Continue to see Figure 3 Based on the above embodiments, the multiplication correction unit 231 optionally includes: a first potentiometer W1; a first end of the first potentiometer W1 is electrically connected to the input end of the amplifying unit 210, and a sliding end of the first potentiometer W1 is electrically connected to the output end of the amplifying unit 210. For example, the first potentiometer W1 can be a digital potentiometer, connected to the correction circuit as a variable resistor. The control unit can control the number of resistors connected between the first end and the sliding end of the first potentiometer W1 by turning on and off each analog switch within the first potentiometer W1, thereby controlling the impedance of the first potentiometer W1 connected between the input and output ends of the amplifying unit 210, thereby achieving impedance adjustment of the multiplication correction unit 231.

[0066] Furthermore, the multiplication correction unit 231 may further include: a first resistor R1 ; the first resistor R1 and the first potentiometer W1 are connected in series between the input terminal and the output terminal of the amplification unit 210 .

[0067] Continue to see Figure 3Based on the above embodiments, the signal correction unit 232 optionally includes: a second potentiometer W2 and a second resistor R2; the first end of the second potentiometer W2 is connected to the first reference signal Vref1, the second end of the second potentiometer W2 is grounded, the sliding end of the second potentiometer W1 is electrically connected to the first end of the second resistor R2, and the second end of the second resistor R2 is electrically connected to the input end of the amplification unit 210. For example, the second potentiometer W2 can be a digital potentiometer, connected to the correction circuit as a voltage divider module. The control unit can control the number of resistors connected between the first end and the sliding end of the second potentiometer W2 by controlling the on and off of each analog switch within the second potentiometer W2, thereby achieving impedance adjustment of the multiplier correction unit 231. In this way, the voltage value output by the sliding end of the second potentiometer W2 can be controlled, that is, the reference voltage value transmitted to the second resistor R2 can be controlled. This reference voltage can be converted into a first adjustment signal in the form of a current by the second resistor R2 and transmitted to the input end of the amplification unit 210.

[0068] Figure 4 This is a schematic diagram of the structure of another voltage correction circuit provided by an embodiment of the present invention, see Figure 4 In one embodiment, the sampling module 10 optionally includes a fifth resistor R5 and a sixth resistor R6, forming a resistor-divider sampling circuit. The first end of the fifth resistor R5 is electrically connected to the output end of the power supply circuit 200; the second end of the fifth resistor R5 is electrically connected to the first end of the sixth resistor R6 and serves as the output end of the sampling module 10; and the second end of the sixth resistor R6 is grounded.

[0069] Furthermore, the sampling module 10 may further include an error amplifier EA; a first input terminal (reverse input terminal) of the error amplifier EA is electrically connected to the second terminal of the fifth resistor R5, a second terminal (positive input terminal) of the error amplifier EA is connected to the second reference signal Vref2, and an output terminal of the error amplifier EA serves as an output terminal of the sampling module 10. The value of the second reference signal Vref2 may be a theoretical value corresponding to the current output voltage Vo. By introducing the error amplifier EA, a deviation between the current output voltage Vo and the theoretical value can be obtained and amplified, so that the correction module 20 generates a correction signal based on the amplified deviation value.

[0070] Furthermore, the sampling module 10 also includes a voltage follower 110; the input end of the voltage follower 110 is electrically connected to the output end of the error amplifier EA, and the output end of the voltage follower 110 serves as the output end of the sampling module 10. The voltage follower 110 can serve as a buffer isolation device between the sampling module 10 and the correction module 20, ensuring that the operations of the modules do not interfere with each other and improving the accuracy of the voltage correction circuit. Specifically, the voltage follower 110 may include a second amplifier OP2 and a seventh resistor R7. The second input end (positive input end) of the second amplifier OP2 is electrically connected to the output end of the error amplifier EA, the output end of the second amplifier OP2 is electrically connected to the first end of the fourth resistor R4, and the seventh resistor R7 is connected between the first input end (negative input end) and the output end of the second amplifier OP2.

[0071] based on Figure 4 The structure shown in the figure can be used to obtain the calculation formula of the correction signal Vc:

[0072] Vc=-(W1+R1)[k(Vref2-Vfb) / R4+Vref1' / R2];

[0073] Wherein, k(Vref2-Vfb) / R4 represents the second adjustment signal, k is the amplification factor of the error amplifier EA, and Vfb is the feedback voltage output by the second end of the fifth resistor R5; Vref1' / R2 represents the first adjustment signal, Vref1' is the reference voltage transmitted to the second resistor R2 via the second potentiometer W2, and its value is related to the characteristics of the second potentiometer W2 itself, the resistance between the first end and the sliding end of the second potentiometer W2, and the value of the first reference signal Vref1, that is, Vref1'=f(Vref1,W2).

[0074] Figure 5 This is a schematic diagram of the structure of another voltage correction circuit provided by an embodiment of the present invention. Figure 5 In one embodiment, the driver module 30 optionally includes a comparator CMP; a first input terminal (positive input terminal) of the comparator CMP is electrically connected to the output terminal of the correction module 20, a second input terminal (negative input terminal) of the comparator CMP is connected to the triangular wave signal Vramp, and an output terminal of the comparator CMP is electrically connected to the control terminal of the power supply circuit 200. The driver module 30 can generate a PWM signal under the control of the correction signal and the triangular wave signal Vramp to control the operation of the power supply circuit 200.

[0075] The power supply circuit 200 may include a power switch device M1 . A control terminal of the power switch device M1 serves as a control terminal of the power supply circuit 200 . The power switch device M1 is configured to control the output of the power supply circuit 200 according to a signal from the control terminal.

[0076] For example, the power supply circuit 200 also includes a power supply E. The on / off state of the power switch device M1 determines whether the voltage of the power supply E can be transmitted to the output terminal of the power supply circuit 200. Therefore, the driving process of the driving module 30 may be as follows: when the correction signal is greater than the triangular wave signal Vramp, the comparator CMP outputs a high level, controlling the power switch device M1 to turn on, allowing the voltage of the power supply E to be transmitted to the output terminal of the power supply circuit 200; when the correction signal is less than the triangular wave signal Vramp, the comparator CMP outputs a low level, controlling the power switch device M1 to turn off, and stopping the voltage of the power supply E from being transmitted to the output terminal of the power supply circuit 200. Accordingly, the voltage correction circuit can adjust the correction signal according to the output voltage Vo, and control the output signal of the comparator CMP according to the correction signal, thereby achieving feedback regulation of the output voltage Vo.

[0077] For example, the power supply circuit 200 can have any topology including a power switching device, such as an LDO circuit, a Buck circuit, a Boost circuit, or a Buck-boost circuit. The specific structure of the power supply circuit 200 is not limited herein. The output terminal of the driver module 30 can be connected to the control terminal of any power switching device in the power supply circuit 200 to control the output state of the power supply circuit 200. The power switching device can be, for example, a MOS transistor, an IGBT, or a thyristor.

[0078] An embodiment of the present invention further provides a display device, comprising a power supply circuit and a voltage correction circuit provided by any embodiment of the present invention, which has corresponding beneficial effects. The display device can be any product or component with a display function, such as a mobile phone, a tablet computer, a television or a monitor. The power supply circuit can be a circuit structure including a power switching device, such as an LDO circuit, a Buck circuit, a Boost circuit or a Buck-boost circuit. For example, the power supply circuit and the voltage correction circuit can be integrated in the driver chip in the display device; or, the power supply circuit is provided in the driver chip, and the voltage correction circuit is provided in other control chips. The specific structure can be set according to actual needs and is not limited here. In addition, the driver chip is also used to provide a data signal to the pixel circuit in the display device to drive the light-emitting device in the pixel circuit to emit light.

[0079] The above specific embodiments do not limit the scope of protection of the present invention. Those skilled in the art will appreciate that various modifications, combinations, sub-combinations, and substitutions may be made based on design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention are intended to be included within the scope of protection of the present invention.

Claims

1. A voltage correction circuit, characterized in that: include: A correction module and a driving module connected in series between the output terminal and the control terminal of the power supply circuit; Wherein, the correction module includes: an amplification unit, a multiplication correction unit and a signal correction unit; The magnification correction unit is connected between the input end and the output end of the amplifying unit; the magnification correction unit is used to adjust the amplification factor of the amplifying unit; The signal correction unit is electrically connected to the input end of the amplifying unit; the signal correction unit is used to adjust the first adjustment signal transmitted to the input end of the amplifying unit; The amplifying unit is electrically connected to the driving module; the amplifying unit generates a correction signal in response to the first adjustment signal and the amplification factor, so that the driving module controls the output voltage of the power supply circuit; The multiplication correction unit has an adjustable impedance; the multiplication correction unit is used to adjust the amplification factor of the amplifying unit by adjusting its impedance; the signal correction unit has an adjustable impedance; the signal correction unit is used to adjust the first adjustment signal transmitted to the input end of the amplifying unit by adjusting its impedance; The output voltage of the power supply circuit is a positive value; when the output voltage of the power supply circuit exceeds a first threshold voltage, the impedance of the multiplication correction unit is adjusted; when the output voltage of the power supply circuit is lower than a second threshold voltage, the impedance of the signal correction unit is adjusted; wherein, the first threshold voltage is greater than the second threshold voltage.

2. The voltage correction circuit according to claim 1, wherein: The correction module also includes: a control unit, which is electrically connected to the output end of the power supply circuit, the multiplication correction unit and the signal correction unit respectively; the control unit is used to control the multiplication correction unit to adjust the amplification factor of the amplification unit according to the output voltage of the power supply circuit, and to control the signal correction unit to adjust the first adjustment signal according to the output voltage of the power supply circuit.

3. The voltage correction circuit according to claim 1, wherein: The multiplication correction unit includes: a first potentiometer; a first end of the first potentiometer is electrically connected to the input end of the amplifying unit, and a sliding end of the first potentiometer is electrically connected to the output end of the amplifying unit.

4. The voltage correction circuit according to claim 3, wherein: The multiplication correction unit further includes: a first resistor; the first resistor and the first potentiometer are connected in series between the input end and the output end of the amplification unit.

5. The voltage correction circuit according to claim 1, wherein: The signal correction unit includes: a second potentiometer and a second resistor; the first end of the second potentiometer is connected to the first reference signal, the second end of the second potentiometer is grounded, the sliding end of the second potentiometer is electrically connected to the first end of the second resistor, and the second end of the second resistor is electrically connected to the input end of the amplification unit.

6. The voltage correction circuit according to claim 1, wherein: The amplifying unit includes: a first amplifier and a third resistor; The first input end of the first amplifier serves as the input end of the amplifying unit, the second input end of the first amplifier is electrically connected to the first end of the third resistor, the second end of the third resistor is grounded, and the output end of the first amplifier serves as the output end of the amplifying unit.

7. The voltage correction circuit according to claim 1, wherein: The correction module further includes: a voltage dividing unit; the voltage correction circuit further includes: a sampling module; The sampling module is electrically connected to the output end of the power supply circuit; the sampling module is used to collect the output voltage of the power supply circuit and generate a sampling signal according to the output voltage; The voltage divider unit is electrically connected to the input end of the amplifying unit and the sampling module respectively; the voltage divider unit is used to generate a second adjustment signal according to the sampling signal; the amplifying unit generates a correction signal in response to the first adjustment signal, the amplification factor and the second adjustment signal.

8. The voltage correction circuit according to claim 7, wherein: The voltage dividing unit includes: a fourth resistor; a first end of the fourth resistor is electrically connected to the sampling module, and a second end of the fourth resistor is electrically connected to the input end of the amplifying unit.

9. The voltage correction circuit according to claim 7, wherein: The sampling module includes: a fifth resistor and a sixth resistor; the first end of the fifth resistor is electrically connected to the output end of the power supply circuit; the second end of the fifth resistor is electrically connected to the first end of the sixth resistor and serves as the output end of the sampling module; the second end of the sixth resistor is grounded.

10. The voltage correction circuit according to claim 9, wherein: The sampling module further includes: an error amplifier; a first input terminal of the error amplifier is electrically connected to the second terminal of the fifth resistor, a second terminal of the error amplifier is connected to a second reference signal, and an output terminal of the error amplifier serves as an output terminal of the sampling module.

11. The voltage correction circuit according to claim 10, wherein: The sampling module further includes: a voltage follower; an input end of the voltage follower is electrically connected to an output end of the error amplifier, and an output end of the voltage follower serves as an output end of the sampling module.

12. The voltage correction circuit according to claim 1, wherein: The driving module includes: a comparator; the power supply circuit includes: a power switch device; The first input terminal of the comparator is electrically connected to the output terminal of the correction module, the second input terminal of the comparator is connected to the triangular wave signal, and the output terminal of the comparator is electrically connected to the control terminal of the power switching device; The control end of the power switch device serves as the control end of the power circuit, and the power switch device is used to control the output of the power circuit according to the signal at its control end.

13. A display device, characterized in that: The device comprises a power supply circuit and a voltage correction circuit as claimed in any one of claims 1 to 12.

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