LCD display power supply system, electronic equipment and LCD display equipment

Abstract

The invention provides an LCD display power supply system, an electronic device and an LCD display device.The LCD display power supply system comprises a first voltage conversion circuit, a second voltage conversion circuit and a control circuit; the first voltage conversion circuit is used for reducing the voltage of an input voltage signal to obtain a first voltage signal; the second voltage conversion circuit is used for stabilizing or reducing the voltage of the first voltage signal to obtain a second voltage signal, and driving a data driving chip of the LCD display equipment by using the second voltage signal; and the control circuit is used for controlling the second voltage conversion circuit to work normally. According to the application, a driving signal required by a data driving chip in the LCD is transmitted by utilizing a'voltage reduction + voltage stabilization 'or'voltage reduction + voltage reduction' framework, so that the cost and the area of peripheral devices can be reduced, the power loss is also reduced, and the power supply efficiency of a power supply system is improved; in addition, a boosting module does not need to be arranged in the PMIC, and the hardware cost of the PMIC is reduced.

Description

Technical Field

[0001] The present application relates to the field of power supply technology, and in particular to an LCD display power supply system, an electronic device and an LCD display device. Background Art

[0002] Liquid Crystal Display (LCD) is a flat ultra-thin display screen. It is widely used in various industries, such as monitors, laptops, and televisions (TVs), due to its advantages of low power consumption, small size, and low radiation. LCD display devices supply power to data driver chips (source driver, gate driver, etc.) through a direct current-direct current (DCDC) conversion circuit or an alternating current direct current (ACDC) conversion circuit to enable the data driver chip to work, thereby enabling the LCD display to display images. Specifically, the power supply process is as follows: the DCDC conversion circuit or the ACDC conversion circuit outputs a power supply voltage signal to a power management integrated chip (PMIC), and the PMIC converts the power supply voltage signal into a driving voltage signal required to drive the data driver chip in the LCD display device.

[0003] In the related art, a boost module is set in the PMIC, and the boost module is used to convert the supply voltage into a driving voltage when the LCD display device is powered. The above power supply method leads to low power supply efficiency and is relatively complex, which also leads to high hardware costs.

[0004] Therefore, how to improve the power supply efficiency of LCD display devices and reduce the hardware cost of the power supply system has become a technical problem that urgently needs to be solved. Summary of the invention

[0005] The present application provides an LCD display power supply system, an electronic device and an LCD display device, which can improve the power supply efficiency of the LCD display device and reduce the hardware cost of the power supply system.

[0006] In a first aspect, the present application provides an LCD display power supply system, comprising: a first voltage conversion circuit, a control circuit, and a second voltage conversion circuit; a first input end of the first voltage conversion circuit is used to receive an input voltage signal, a first output end of the first voltage conversion circuit is electrically connected to a first end of the second voltage conversion circuit, and a second end of the second voltage conversion circuit is electrically connected to a data driving chip of a liquid crystal LCD display device; a control end of the second voltage conversion circuit is electrically connected to a first output end of the control circuit;

[0007] The control circuit is used to provide a control signal to the second voltage conversion circuit to control the operation of the second voltage conversion circuit;

[0008] The first voltage conversion circuit is used to step down the input voltage signal to obtain a first voltage signal, and input the first voltage signal to the second voltage conversion circuit; the magnitude of the first voltage signal meets the voltage required by the data driver chip, or the magnitude of the first voltage signal is higher than the voltage required by the data driver chip;

[0009] The second voltage conversion circuit is used to perform voltage stabilization or voltage reduction or switch control on the first voltage signal to obtain a second voltage signal, and transmit the second voltage signal to the data driver chip to drive the data driver chip to work.

[0010] In the solution of this embodiment, the LCD display power supply system can stably output the power supply signal required by the data driving chip inside the LCD display, and the LCD display power supply system has low cost and high power supply efficiency.

[0011] In a possible design, the second voltage conversion circuit is a linear DC regulator (Low-dropout regulator, LDO), or a step-down conversion circuit, or a switching tube.

[0012] In a possible design, when the second voltage conversion circuit is an LDO, the second voltage conversion circuit supports voltage stabilization and switch control of the first voltage signal at the same time;

[0013] When the second voltage conversion circuit is a step-down conversion circuit, the second voltage conversion circuit supports simultaneous step-down processing and switch control of the first voltage signal.

[0014] In a possible design, the second output terminal of the control circuit is electrically connected to the second input terminal of the first voltage conversion circuit;

[0015] The control circuit is further configured to generate a feedback control signal and send the feedback control signal to the first voltage conversion circuit;

[0016] The first voltage conversion circuit is further used to adjust the first voltage signal output by the voltage conversion circuit according to the feedback control signal.

[0017] In one possible design, the second voltage conversion circuit and / or the control circuit are integrated into a power management integrated chip PMIC.

[0018] In a possible design, the first output end of the first voltage conversion circuit is also electrically connected to the audio output device of the LCD display device, so as to provide an operating voltage to the audio output device.

[0019] In the solution of this embodiment, the audio output device and the data driver chip share one output, thereby saving the cost of one output and reducing the cost of the power supply system.

[0020] In one possible design, the voltage conversion circuit is an adjustable ACDC conversion circuit, or the voltage conversion circuit is an adjustable DCDC conversion circuit.

[0021] In some possible designs, the first output end of the first voltage conversion circuit is also electrically connected to the voltage input end of the DCDC conversion circuit of the system main control board of the LCD display device, and the system main control board DCDC conversion circuit is used to supply power to the chip on the main control board.

[0022] In the solution of this embodiment, the system main control board DCDC conversion circuit and the data driver chip share one output, which saves one output cost compared to each separate output, and reduces the cost of the power supply system. When the system main control board DCDC conversion circuit, the audio output device and the data driver chip share one output, at least two output costs are saved compared to each separate output.

[0023] In a second aspect, the present application provides an electronic device, comprising: an LCD display power supply system as described in any one of the first aspects.

[0024] In a third aspect, the present application provides an LCD display device, an LCD display screen, and an LCD display power supply system according to any one of the first aspects, wherein the LCD display power supply system is electrically connected to a data driver chip in the LCD display screen;

[0025] The LCD display power supply system is used to provide a second voltage signal to the data driving chip;

[0026] The data driving chip is used to work under the drive of the second voltage signal to enable the LCD display screen to display an image.

[0027] The present application provides an LCD display power supply system, an electronic device and an LCD display device, wherein the LCD display power supply system includes: a first voltage conversion circuit, a second voltage conversion circuit and a control circuit; the first voltage conversion circuit is used to step down the input voltage signal to obtain a first voltage signal; the second voltage conversion circuit is used to stabilize or step down the first voltage signal to obtain a second voltage signal, and use the second voltage signal to drive the data driver chip of the LCD display device; the control circuit is used to control the second voltage conversion circuit to work normally. The present application uses the "step-down + voltage stabilization" architecture or the "step-down + step-down" architecture to provide the driving voltage signal required by the data driver chip inside the LCD, which can reduce the cost and area of ​​peripheral devices, reduce power loss, and improve the power supply efficiency of the power supply system; the present application also does not need to set a boost module in the PMIC, reducing the hardware cost of the PMIC. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1A The power supply system architecture diagram of a notebook computer / monitor in the related art is exemplified;

[0029] Figure 1B Schematic diagram of the structure of the peripheral circuit and the control circuit in the related art;

[0030] Figure 1C The power supply system architecture diagram of a TV in the related art is exemplified;

[0031] Figure 2 A structural diagram of an LCD display power supply system provided in one embodiment of the present application;

[0032] Figure 3A A structural diagram of an LCD display power supply system provided by another embodiment of the present application;

[0033] Figure 3B A structural diagram of an LCD display power supply system provided by another embodiment of the present application;

[0034] Figure 4 A structural diagram of an LCD display power supply system provided by another embodiment of the present application;

[0035] Figure 5 A structural diagram of an LCD display power supply system provided by another embodiment of the present application;

[0036] Figure 6 A structural diagram of an LCD display device provided in one embodiment of the present application. DETAILED DESCRIPTION

[0037] In this application, "at least one" means one or more, and "plurality" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. The character " / " generally indicates that the associated objects before and after are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b, or c alone can represent: a, b, c, a and b, a and c, or a, b, and c, where a, b, and c can be single or multiple. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0038] The directions or positional relationships indicated by terms such as "center", "longitudinal", "lateral", "up", "down", "left", "right", "front", and "back" are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present application and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present application.

[0039] The terms "connected" and "connected" should be understood in a broad sense. For example, the "connected" or "connected" of a circuit structure can refer to not only physical connection, but also electrical connection or signal connection. For example, it can be directly connected, that is, physically connected, or indirectly connected through at least one intermediate element, as long as the circuit is connected, or it can be the internal connection of two elements; signal connection can refer to signal connection through a circuit or through a media medium, such as radio waves. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0040] Figure 1A This is a diagram of the power supply system architecture of a laptop / monitor in the related art. Figure 1A As shown, the power supply system of the notebook computer / monitor mainly includes a main board and a boost module. The main board includes: a DCDC conversion circuit. The boost module can also be called a boost module, a boost conversion circuit, a boost circuit module, etc., and is mainly used for boost conversion.

[0041] The DCDC conversion circuit on the mainboard receives the DC voltage signal input by the external adapter (the DC voltage signal input by the adapter can be a fixed 12V / 19V / 24V), and then converts the DC voltage signal into a 12V power supply voltage; the 12V power supply voltage is then boosted by the boost module, and the 12V power supply voltage is converted into a 15.2V high voltage required by the data driver chip. The external adapter is used to receive the AC input voltage of the power grid and convert the AC input voltage into a DC voltage signal.

[0042] The power supply method in the related technology adopts the "step-down + step-up" architecture, which performs two voltage conversions. The voltage difference before and after each voltage conversion is large, so the power loss is large and the power supply efficiency is low. The overall power supply efficiency is the product of the efficiencies of the two voltage conversions. Since the power loss caused by each voltage conversion is large, the power supply efficiency will be greatly reduced after multiplication.

[0043] Figure 1A The boost module shown includes: a peripheral circuit and a boost control circuit. The peripheral circuit is mainly used to realize voltage conversion; the boost control circuit is used to control the working state of each electronic component in the peripheral circuit. Figure 1B FIG. 1 is a block diagram of an exemplary peripheral circuit and a boost control circuit. Figure 1B As shown, the peripheral circuit includes: an inductor L0, a first switch tube M1, and M1 is an N-channel Metal-Oxide-Semiconductor (NMOS), a diode VD1, and a second switch tube M2, M2 is a P-type Metal-Oxide Semiconductor Field Effect Transistor (positive channel Metal Oxide Semiconductor, MOS), wherein the first switch tube M1 is grounded through a resistor. The boost control circuit is used to control the working state of each electronic component in the peripheral circuit, so that the peripheral circuit works normally.

[0044] Figure 1C This is a diagram of the power supply system architecture of a TV in the related art. Figure 1C As shown, the power supply system of the TV mainly includes a power board and a boost module. Among them, the power board includes: ACDC conversion circuit.

[0045] The ACDC conversion circuit on the power board receives the 220V AC input voltage from the power grid and converts it into a 12V supply voltage; the 12V supply voltage is then boosted by the boost module to convert the 12V supply voltage into the 15.2V high voltage required by the data driver chip.

[0046] Among them, the boost module in the TV power supply system can also be used as follows Figure 1B The circuit implementation shown is not described here in detail for the sake of simplicity.

[0047] In summary, combined Figure 1A , Figure 1B as well as Figure 1C As shown, in the related art, the peripheral circuit has a large number of electronic components and a complex design, resulting in a high hardware cost for the power supply system.

[0048] Therefore, how to solve the low power supply efficiency and reduce hardware costs has become a technical problem that needs to be solved urgently.

[0049] In order to solve the above problems, the present application provides an LCD display power supply system, an electronic device and an LCD display device. The LCD display power supply system of the present application collects a two-stage cascade architecture of "step-down + voltage regulation" or a two-stage cascade architecture of "step-down + step-down" to convert the input voltage signal into the voltage required by the LCD internal data driver chip. In the present application, the power loss caused by each stage of voltage conversion is small, so the power loss is greatly reduced, thereby improving the power supply efficiency of the LCD display power supply system; in addition, in the power supply system provided by the present application, the peripheral circuit structure that cooperates with the second-stage voltage conversion circuit is simple, and requires fewer electronic components to implement, thereby reducing the hardware cost. In addition, on the basis of the present application, it is also possible to eliminate the need to set a boost module in the PMIC, further reducing the hardware cost of the power supply system.

[0050] The LCD display power supply system provided in this application is applicable to any of the following types of LCD display devices. For example, laptops, monitors, televisions, desktop computers, vertical advertising machines, wall-mounted advertising machines, elevator building advertising machines, horizontal query machines, self-service terminals, teaching machines, outdoor electronic newspaper racks, smart lamp poles, smart garbage classification boxes, smart bus stops, vehicle-mounted equipment, smart home equipment, LCD splicing display equipment, smart robots, industrial control equipment, etc.

[0051] Next, the LCD display power supply system provided by the present application is introduced in detail through some specific embodiments.

[0052] Figure 2 This is a structural diagram of an LCD display power supply system provided by an embodiment of the present application. Figure 2 As shown, the LCD display power supply system 20 includes: a first voltage conversion circuit 21, a control circuit 22 and a second voltage conversion circuit 23.

[0053] The first input terminal ( Figure 2 denoted by reference numeral 1) is used to receive the input voltage signal V IN The first output terminal ( Figure 22) and the first terminal ( Figure 2 1 in the figure) is electrically connected to the second end ( Figure 2 The control terminal ( denoted by reference numeral 2 ) of the second voltage conversion circuit 23 is electrically connected to a pin on the data driver chip of the LCD display device for receiving a driving voltage signal. The pin for receiving a driving voltage signal may be, but is not limited to, an AVDD pin. The following embodiments are all described using the AVDD pin as an example. Figure 2 denoted by reference numeral 3) and the first output terminal of the control circuit 22 ( Figure 2 Indicated by reference numeral 1) connection.

[0054] The first voltage conversion circuit 21 may be an ACDC conversion circuit or a DCDC conversion circuit. In practical applications, the type of the first voltage conversion circuit 21 used by the first voltage conversion circuit 21 depends on whether the circuit module at the front end of the first voltage conversion circuit 21 in the LCD display device can provide an AC or DC input voltage signal. The present application does not limit the specific structure of the first voltage conversion circuit 21.

[0055] For example, if the LCD display device is a device with a small LCD screen size, such as a monitor or a notebook, if there is a circuit module in such a device that converts the AC input voltage signal of the power grid into a DC voltage signal and is cascaded at the front end of the first voltage conversion circuit 21, then the first voltage conversion circuit 21 is a DCDC conversion circuit. If the LCD display device is a device with a large LCD screen size, such as a TV, the first voltage conversion circuit 21 in such a device may be an ACDC conversion circuit.

[0056] The magnitude of the first voltage signal output by the first voltage conversion circuit 21 can meet the voltage required by the data driving chip, or the magnitude of the first voltage signal is higher than the voltage required by the data driving chip.

[0057] exist Figure 2 On the basis of the illustrated embodiment, the first voltage conversion circuit 21 may be a circuit module or chip that outputs a non-adjustable voltage, or may be a circuit module or chip that can output an adjustable voltage. The present application does not limit the voltage range that the first voltage conversion circuit 21 can output. For example, when the first voltage conversion circuit 21 is an ACDC conversion circuit, it may output a DC voltage signal in the range of 15V-16.5V, or, when the first voltage conversion circuit 21 is a DCDC conversion circuit, it may output a DC voltage signal in the range of 14V-20V.

[0058] Among them, when the output of the first voltage conversion circuit 21 is adjustable, the LCD display power supply system provided by the present application can be applied to LCD display screens of various specifications. Among them, when the output of the first voltage conversion circuit 21 is not adjustable, and the second voltage conversion circuit 23 adopts a buck architecture for step-down, the LCD display power supply system provided by the present application can also be applied to LCD display screens of various specifications (such as the following situation 3); if the output of the first voltage conversion circuit 21 is adjustable, and the second voltage conversion circuit 23 adopts a buck architecture for step-down, the power supply efficiency of the LCD display power supply system provided by the present application will be higher, and the cost may be lower.

[0059] In some embodiments, the second voltage conversion circuit 23 and / or the control circuit 22 are integrated into a PMIC of the LCD display device.

[0060] For example, the control circuit 22 is integrated in the PMIC, and the second voltage conversion circuit 23 is a circuit module or chip (such as Figure 3B ).

[0061] For another example, the second voltage conversion circuit 23 and the control circuit 22 are both integrated in the PMIC (eg Figure 3A shown).

[0062] For another example, the second voltage conversion circuit 23 is integrated in the PMIC, and the control circuit 22 is a circuit module or chip arranged outside the PMIC.

[0063] It should be noted that the second voltage conversion circuit 23 and the control circuit 22 may not be integrated in the PMIC.

[0064] The second voltage conversion circuit 23 has at least one of a voltage stabilization function, a voltage reduction function, and a switch control function. In some special cases, the second voltage conversion circuit 23 has both a voltage stabilization function and a switch control function, or has both a voltage reduction function and a switch control function.

[0065] Regarding the voltage stabilization function, the present application takes into account that during the operation of the LCD display power supply system, the first voltage signal output by the first voltage conversion circuit 21 may be limited by the dynamic response or affected by the noise signal, and the output first voltage signal may be jittery. Furthermore, if an unstable power supply is transmitted to the data driver chip, the stability of the data driver chip may be reduced, thereby failing to stably control the LCD display screen. Based on this, the present application considers the second voltage conversion circuit 23 to perform voltage stabilization processing on the first voltage signal, remove the noise signal in the first voltage signal, and stabilize the voltage signal input to the data driver chip, thereby improving the stability of the data driver chip and the stability of the LCD display device. In addition, the voltage stabilization processing usually causes a small change in the signal voltage difference before and after the processing, so the power loss is also small, which is also beneficial to improving the power supply efficiency of the LCD display power supply system.

[0066] Regarding the switch control function, considering that the first voltage conversion circuit 21 of the previous stage converts the input voltage signal into a voltage required by the data driver chip, the switch control can be used to supply power to or stop the data driver chip, and basically no power loss will occur, which can improve the control flexibility of the power supply system.

[0067] The second voltage conversion circuit 23 has two working states: an on state and an off state. When the second voltage conversion circuit 23 is in the on state, the first voltage signal output by the first voltage conversion circuit 21 can be successfully transmitted to the data driver chip as a driving voltage signal; when the second voltage conversion circuit 23 is in the off state, the first voltage signal output by the first voltage conversion circuit 21 cannot be transmitted to the data driver chip, that is, the power supply to the data driver chip stops.

[0068] Regarding the step-down function, considering that the first voltage conversion circuit 21 of the previous stage converts the input voltage signal into a voltage slightly higher than the voltage required by the data driver chip, the step-down function can be used to further step down the first voltage signal output by the first voltage conversion circuit 21. Since the first voltage signal is close to the voltage required by the data driver chip, the power loss caused by the second-stage voltage conversion circuit is relatively small, which is beneficial to improving the power supply efficiency.

[0069] The second voltage conversion circuit 23 may be an LDO, a buck circuit or a switch tube.

[0070] Case (1): the second voltage conversion circuit 23 is an LDO.

[0071] LDO can provide voltage regulation and switch control functions at the same time.

[0072] The present application may adopt any existing type of LDO. Among them, the LDO can be implemented by a power transistor, and the power transistor can be but is not limited to a bipolar transistor or a field effect transistor. Exemplarily, when the LDO is implemented by a controllable PMOS, the gate of the PMOS is electrically connected to the first end of the control circuit 22, the source of the PMOS is electrically connected to the first output end of the first voltage conversion circuit 21, and the drain of the PMOS is electrically connected to the data driver chip. The control circuit 22 controls the state of the PMOS by inputting a control signal to the PMOS.

[0073] In case 1, the input AC voltage signal is 220V, and the voltage required by the data driver chip is 15.2V. Figure 2 The working process of the power supply system shown is as follows: the first voltage conversion circuit 21 receives the input voltage signal V IN , input voltage signal V IN The first voltage conversion circuit 21 converts the 220V input voltage signal V IN The first voltage signal is converted into a first voltage signal. The first voltage signal may also be called bus power supply voltage, bus power supply, or other names. The magnitude of the first voltage signal may be 15.2V or may be slightly higher than 15.2V, such as 16.0V. At the same time, the control circuit 22 inputs a control signal to the second voltage conversion circuit 23 to turn on the second voltage conversion circuit 23. The LDO then stabilizes the first voltage signal and outputs a 15.2V second voltage signal V AVDD In this way, the second voltage signal is input to the AVDD pin of the data driver chip as a driving voltage signal, and the data driver chip is based on the second voltage signal V AVDD Get to work.

[0074] When the first voltage conversion circuit 21 is higher than the first voltage signal required by the data driver chip, the voltage difference between the first voltage signal and the voltage signal required by the data driver chip may be less than or equal to a preset threshold. The present application does not limit the value of the preset threshold, for example, it may be 0.2, 0.5, 0.8, etc.

[0075] Case (2): the second voltage conversion circuit 23 is a switch tube.

[0076] The switch tube may refer to a MOS, such as NMOS, PMOS, etc. Exemplarily, the second voltage conversion circuit 23 is a PMOS, the gate of the PMOS is electrically connected to the first end of the control circuit 22, the source of the PMOS is electrically connected to the first output end of the first voltage conversion circuit 21, and the drain of the PMOS is electrically connected to the data driver chip. The control circuit 22 controls the PMOS to turn on or off by inputting a control signal to the PMOS.

[0077] The switch tube may also refer to a group of back-to-back MOS tubes, wherein the back-to-back MOS tubes refer to two MOS tubes whose gates are connected together to form a bidirectional switch.

[0078] In case (2), take the input voltage signal as 220V and the voltage required by the data driver chip as 15.2V as an example. Figure 2 The working process of the power supply system shown is as follows: the first voltage conversion circuit 21 receives the input voltage signal V IN , input voltage signal V IN The first voltage conversion circuit 21 converts the 220V input voltage signal V IN The first voltage signal is converted into a first voltage signal with a magnitude of 15.2V. At the same time, the control circuit 22 inputs a control signal to the second voltage conversion circuit 23, so that the second voltage conversion circuit 23 is in a conducting state. In this way, the first voltage signal passes through the switch tube to obtain a 15.2V second voltage signal V AVDD It is input to the AVDD pin of the data driver chip as a driving voltage signal.

[0079] For situations (1) and (2), Figure 1B Compared with the peripheral circuit shown in the figure, the peripheral circuit in the related art includes four electronic components: inductor L0, NMOS tube, diode VD1 and PMOS tube. When the second voltage conversion circuit 23 of the LCD display power supply system provided by the present application can be realized by a PMOS, Figure 1B Compared with the peripheral circuit shown, the inductor L0, NMOS tube and diode VD1 save a total of three electronic components, thereby saving the hardware cost of the power supply system. In addition, there is no need to set a circuit module for controlling the inductor L0, NMOS tube and diode VD1 in the PMIC, which further saves the hardware cost of the power supply system. When the second voltage conversion circuit 23 in the LCD display power supply system provided by the present application is implemented by back-to-back MOS tubes, at least two electronic components, the inductor L0 and the diode VD1, can be saved, thereby saving the hardware cost of the power supply system.

[0080] Case (3): the second voltage conversion circuit 23 is a buck circuit.

[0081] The buck circuit can provide both voltage regulation and switch control functions.

[0082] The present application does not limit the structure of the buck circuit. Exemplarily, the buck circuit includes: a switch tube and an LC low-pass filter, and the LC low-pass filter is composed of an inductor and a capacitor. The control circuit 22 can control the output voltage and the conduction state of the buck circuit by controlling the state of the switch tube in the buck circuit.

[0083] In case (3), take the input voltage signal as 220V and the voltage required by the data driver chip as 15.2V as an example. Figure 2 The working process of the power supply system shown is as follows: the first voltage conversion circuit 21 receives the input voltage signal V IN , input voltage signal V IN The first voltage conversion circuit 21 converts the 220V input voltage signal V IN The first voltage signal is converted into a first voltage signal with a magnitude of 20V. At the same time, the control circuit 22 inputs a control signal to the second voltage conversion circuit 23, so that the second voltage conversion circuit 23 is in a conducting state. In this way, the first voltage signal becomes a second voltage signal V of 15.2V after passing through the buck circuit. AVDD And it is input to the AVDD pin of the data driver chip as a driving voltage signal.

[0084] For situation (3), Figure 1B Compared with the peripheral circuit shown in the figure, the peripheral circuit in the related art includes four electronic components: inductor L0, NMOS tube, diode VD1 and PMOS tube. When the second voltage conversion circuit 23 of the LCD display power supply system provided by the present application can be implemented by a buck circuit, Figure 1B Compared with the peripheral circuit shown, one electronic component is basically saved, thereby saving the hardware cost of the power supply system.

[0085] It should be noted that the examples in the above situations (1) to (3) all use the first voltage conversion circuit 21 as an ACDC conversion circuit, and the input voltage signal V IN Taking a 220V AC input voltage signal as an example, when the input voltage signal V IN In the case of a DC voltage signal, the working process of the LCD display power supply system is similar to the examples in the above situations (1) to (3), except that the first voltage conversion circuit 21 is a DCDC conversion circuit.

[0086] In summary, the LCD display power supply system provided in this embodiment adopts a two-stage cascade architecture of "step-down + voltage regulation" or a two-stage cascade architecture of "step-down + step-down", which can effectively reduce the power loss caused by voltage conversion, thereby improving the power supply efficiency of the power supply system; in addition, in this application, the peripheral circuit structure that cooperates with the second voltage conversion circuit is simple, requiring fewer electronic components to implement, reducing hardware costs. In addition, based on this application, there is no need to set a boost module in the PMIC, further reducing the hardware cost of the power supply system.

[0087] Figure 4 This is a structural diagram of an LCD display power supply system provided by another embodiment of the present application. Figure 4 As shown, in this embodiment Figure 2 Based on the embodiment shown, the first output terminal of the first voltage conversion circuit 21 is also electrically connected to the first terminal of the control circuit 22, and the second output terminal of the control circuit 22 is also electrically connected to the second input terminal of the first voltage conversion circuit 21. Figure 4 Indicated by reference numeral 3) connection.

[0088] The control circuit 22 is used to generate a feedback control signal (feed back), and the control circuit 22 sends the feedback control signal to the first voltage conversion circuit 21. The first voltage conversion circuit 21 is also used to adjust the output first voltage signal according to the feedback control signal to adapt to the second voltage conversion circuit 23, thereby improving the stability and accuracy of the output second voltage signal (that is, the driving voltage signal required by the data driver chip).

[0089] The present application does not limit the implementation method of the control circuit 22 generating the feedback control signal.

[0090] In some embodiments, the control circuit 22 includes a first input terminal and a second input terminal, the first input terminal is electrically connected to the first output terminal of the first voltage conversion circuit 21, and the second input terminal is electrically connected to the second terminal of the second voltage conversion circuit 23. Based on this, the control circuit 22 collects the first voltage signal and the second voltage signal, and then inputs the two collected signals into the error amplifier in the control circuit 22, and uses the error amplifier to process the two collected signals to obtain the error signal of the first voltage signal and the second voltage signal, and transmits the error result as a feedback control signal to the first voltage conversion circuit 21, thereby adjusting the first voltage signal output by the first voltage conversion circuit 21 to adapt to the second voltage conversion circuit 23. Among them, the control circuit 22 can collect the first voltage signal and the second voltage signal through a voltage divider circuit, and the voltage divider circuit can be realized by connecting multiple resistors in series, and the voltage divider circuit can provide a fixed voltage divider coefficient.

[0091] In other embodiments, an input terminal of the control circuit 22 is electrically connected to the first output terminal of the first voltage conversion circuit 21. The control circuit 22 collects the first voltage signal actually outputted, determines the error signal between the first voltage signal actually outputted and the expected first voltage signal, and then outputs the error signal as a feedback control signal to the first voltage conversion circuit 21, thereby adjusting the first voltage signal outputted by the first voltage conversion circuit 21, and further adapting the second voltage conversion circuit 23, adjusting the actual output of the second voltage conversion circuit 23, so that the actual output of the second voltage conversion circuit 23 meets the requirements of the data driver chip.

[0092] In other embodiments, an input terminal of the control circuit 22 is electrically connected to the output terminal of the second voltage conversion circuit. The control circuit 22 collects the second voltage signal actually output, determines the error signal between the second voltage signal actually output and the expected second voltage signal, and then outputs the error signal as a feedback control signal to the first voltage conversion circuit 21, thereby adjusting the first voltage signal output by the first voltage conversion circuit 21, and further adapting the second voltage conversion circuit 23, adjusting the actual output of the second voltage conversion circuit 23, so that the actual output of the second voltage conversion circuit 23 meets the requirements of the data driver chip.

[0093] The LCD display power supply system provided in this embodiment adds a feedback branch so that the first voltage conversion circuit of the previous stage can be continuously adjusted according to the actual output of itself or the second voltage conversion circuit of the next stage, so that the actual output of the second voltage conversion circuit 23 meets the requirements of the data driver chip.

[0094] Figure 5 This is a structural diagram of an LCD display power supply system provided by another embodiment of the present application. Figure 5 As shown, in this embodiment Figure 2 On the basis of the illustrated embodiment, the first output terminal of the first voltage conversion circuit 21 may also be electrically connected to an audio output device to provide an operating voltage to the audio output device.

[0095] The audio output device is used to play audio content and is an essential and important module in the LCD display device. The audio output device can be a speaker, i.e., a "speaker". The speaker can be, but is not limited to, an electric speaker, an electrostatic speaker, an electromagnetic speaker, and a piezoelectric speaker.

[0096] The audio output device can be built into the LCD display device, or it can be set up externally and connected to the audio input / output interface provided by the LCD display device via a cable. This application does not limit this.

[0097] It should be understood that the minimum voltage signal that can be output by the first voltage conversion circuit 21 should meet the minimum output power requirement of the audio output device. In addition, the maximum voltage signal that can be output by the first voltage conversion circuit 21 should be less than the maximum operating voltage allowed by the audio output device, so that the audio output device can be prevented from malfunctioning due to an excessively high input operating voltage, so that the audio output device can operate safely and reliably.

[0098] In the related art, for example, the DCDC conversion circuit in the power supply system of a laptop / monitor and the ACDC conversion circuit in the power supply system of a TV provide voltage signals to the boost module and the audio output module through two output terminals, and the voltage signals are different in size, that is, the related art adopts a two-way output solution for the data driver chip and the audio output. In the solution of this embodiment, the data driver chip and the audio output device share one output terminal. Compared with the power supply method in the related art, the power supply method of this application saves one-way output cost, ensures that the actual output power of the audio output device meets expectations, and enables the audio output device to operate safely and reliably.

[0099] It should be noted that Figure 5 The method shown also applies to Figure 3A , Figure 3B For scenarios where Figure 4 As shown, when there is a feedback branch in the LCD display power supply system, the first output end of the first voltage conversion circuit 21 can also be electrically connected to the audio output device to provide a working voltage to the audio output device.

[0100] Please continue reading Figure 5 Optionally, the first output end of the first voltage conversion circuit 21 can also be connected to a system main control board DCDC conversion circuit, wherein the system main control board DCDC conversion circuit is used to supply power to the chip on the main control board.

[0101] The main control board refers to the circuit board in the LCD display device that is mainly used to perform control-related operations. It can also be understood as the central processing unit. The main control board includes multiple chips, such as the main control chip, the image quality chip, etc.

[0102] The system main control board DCDC conversion circuit can convert the first voltage signal output by the first voltage conversion circuit 21 into a voltage signal required by the chip on the main control board. This application does not limit the system main control board DCDC conversion circuit to one output or multiple outputs, which can be set according to actual conditions.

[0103] It should be understood that in this embodiment, the output voltage upper limit of the first voltage conversion circuit 21 needs to be compatible with the input voltage upper limit of the system DCDC, so that the system main control board DCDC conversion circuit can operate safely and reliably. Exemplarily, when the input voltage upper limit of the system main control board DCDC conversion circuit is 18V, the first voltage conversion circuit 21 can use an adjustable ACDC conversion circuit with an output voltage range of 15V-16.5V to avoid failure of the system main control board DCDC conversion circuit due to excessively high input voltage.

[0104] In the LCD display power supply system of this embodiment, the data driver chip, the audio output device and the system main control board DCDC conversion circuit share one output terminal. Compared with the power supply method of each separate output, the power supply method of this application saves the cost of 2 outputs. Combined with the example of situation (1) in the above text, the bus power supply is 15.2V or 16.0V, which can simultaneously power the system main control board DCDC conversion circuit and the audio output device, thereby saving one or two outputs of the first voltage conversion module, further saving system costs.

[0105] Exemplarily, when the first output end of the first voltage conversion circuit 21 can output a voltage range of 15V-16.5V (that is, it can adapt to the situation of the second voltage conversion circuit), the audio output device can use a 20V operating voltage, and the upper limit of the input voltage supported by the system main control board DCDC conversion circuit is 18V. In this way, the first voltage conversion circuit 21 adopts a single-port output and simultaneously powers the second voltage conversion circuit, the audio output device and the system main control board DCDC conversion circuit.

[0106] It should be noted that in some scenarios, the DC voltage signal output by the first voltage conversion circuit 21 does not match the requirements of the audio output device and cannot meet the output power requirements of the audio output device. In this case, the first voltage conversion circuit 21 can be implemented with a structure having multiple output terminals, that is, the working voltage required by the audio output device can be provided through one output alone. On this basis, the data driver chip and the system main control board DCDC conversion circuit can share one output, or the system main control board DCDC conversion circuit can share one output with the audio output device.

[0107] Exemplarily, when the first output end of the first voltage conversion circuit 21 can output a voltage range of 15V-16.5V (that is, it can adapt to the situation of the second voltage conversion circuit), the audio output device needs to use a fixed 12V working voltage, and the upper limit of the input voltage supported by the system main control board DCDC conversion circuit is 18V. In this way, the first voltage conversion circuit 21 adopts a multi-port output. For example, the first output end of the first voltage conversion circuit 21 is used to provide a first voltage signal to the second voltage conversion circuit 23, and the second output end of the first voltage conversion circuit 21 is used to provide a 12V working voltage to the audio output device and the system main control board DCDC conversion circuit. For another example, the first output end of the first voltage conversion circuit 21 is used to provide a first voltage signal to the second voltage conversion circuit 23 and the system main control board DCDC conversion circuit, and the second output end of the first voltage conversion circuit 21 is used to provide a working voltage, such as a 12V DC voltage, to the audio output device.

[0108] Figure 6 This is a structural diagram of an LCD display device provided by an embodiment of the present application. Figure 6As shown, the display device 50 provided in this embodiment includes: an LCD display power supply system and an LCD display screen.

[0109] The LCD display power supply system includes: a first voltage conversion circuit, a control circuit and a second voltage conversion circuit, wherein the output end of the second voltage conversion circuit is electrically connected to a pin (such as an AVDD pin) on the data driver chip for receiving a second voltage signal.

[0110] The LCD display power supply system can adopt the technical solution of any of the aforementioned method embodiments. Its implementation principle and technical effects can be referred to the detailed description above. For the sake of brevity, they will not be repeated here.

[0111] Specifically, the LCD display power supply system provides the required second voltage signal to the data driving chip, so that the data driving chip starts to work, thereby enabling the LCD display screen to display images.

[0112] It should be noted that the data driver chip may also require other voltage signals to work, and this application does not limit this.

[0113] In some embodiments, the LCD display device further includes: an audio output device ( Figure 6 not shown).

[0114] The first output terminal of the voltage conversion circuit in the LCD display power supply system is also electrically connected to the audio output device to provide an operating voltage to the audio output device.

[0115] In some embodiments, the LCD display device further includes: a system main control board DCDC conversion circuit ( Figure 6 not shown).

[0116] The first output end of the first voltage conversion circuit in the LCD display power supply system is also electrically connected to the input end of the system main control board DCDC conversion circuit to provide a first voltage signal as an input voltage signal to the system main control board DCDC conversion circuit, and the system main control board DCDC conversion circuit converts the first voltage signal into the power required by the chip on the main control board.

[0117] The present application also provides an electronic device, including: an LCD display power supply system provided in any of the above embodiments.

[0118] Finally, it should be noted that the above embodiments are only specific implementation methods of the present application, but the protection scope of the present application is not limited thereto, and any changes or substitutions within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. An LCD display power supply system, characterized in that: include: a first voltage conversion circuit, a control circuit, and a second voltage conversion circuit; the first input end of the first voltage conversion circuit is used to receive an input voltage signal, the first output end of the first voltage conversion circuit is electrically connected to the first end of the second voltage conversion circuit, and the second end of the second voltage conversion circuit is electrically connected to a data driving chip of a liquid crystal LCD display device; the control end of the second voltage conversion circuit is electrically connected to the first output end of the control circuit; The control circuit is used to provide a control signal to the second voltage conversion circuit to control the operation of the second voltage conversion circuit; The first voltage conversion circuit is used to step down the input voltage signal to obtain a first voltage signal, and input the first voltage signal to the second voltage conversion circuit; the magnitude of the first voltage signal meets the voltage required by the data driver chip, or the magnitude of the first voltage signal is higher than the voltage required by the data driver chip; The second voltage conversion circuit is used to perform voltage stabilization or voltage reduction or switch control on the first voltage signal to obtain a second voltage signal, and transmit the second voltage signal to the data driver chip to drive the data driver chip to work.

2. The power supply system according to claim 1, characterized in that: The second voltage conversion circuit is a linear direct current regulator LDO, or a step-down conversion circuit, or a switch tube.

3. The power supply system according to claim 2, characterized in that: When the second voltage conversion circuit is an LDO, the second voltage conversion circuit supports voltage stabilization and switch control of the first voltage signal at the same time; When the second voltage conversion circuit is a step-down conversion circuit, the second voltage conversion circuit supports simultaneous step-down processing and switch control of the first voltage signal.

4. The power supply system according to claim 1, characterized in that: The second output terminal of the control circuit is electrically connected to the second input terminal of the first voltage conversion circuit; The control circuit is further configured to generate a feedback control signal and send the feedback control signal to the first voltage conversion circuit; The first voltage conversion circuit is further used to adjust the first voltage signal output by the voltage conversion circuit according to the feedback control signal.

5. The power supply system according to claim 1, characterized in that: The second voltage conversion circuit and / or the control circuit are integrated in a power management integrated chip PMIC.

6. The power supply system according to claim 1, characterized in that: The first output end of the first voltage conversion circuit is also electrically connected to the audio output device of the LCD display device, and is used to provide an operating voltage to the audio output device.

7. The power supply system according to claim 1, characterized in that: The first voltage conversion circuit is an adjustable ACDC conversion circuit, or the voltage conversion circuit is an adjustable DCDC conversion circuit.

8. The power supply system according to claim 1, characterized in that: The first output end of the first voltage conversion circuit is also electrically connected to the voltage input end of the DCDC conversion circuit of the system main control board of the LCD display device, and the DCDC conversion circuit of the system main control board is used to supply power to the chip on the main control board.

9. An electronic device, characterized in that: include: The LCD display power supply system according to any one of claims 1 to 8.

10. An LCD display device, characterized in that: include: An LCD display screen and an LCD display power supply system according to any one of claims 1 to 8, wherein the LCD display power supply system is electrically connected to a data driving chip in the LCD display screen; The LCD display power supply system is used to provide a second voltage signal to the data driving chip; The data driving chip is used to work under the drive of the second voltage signal to enable the LCD display screen to display an image.

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