Power supply circuit and AMOLED display device

Abstract

The invention provides a power supply circuit and an AMOLED display device. The power supply voltage comprises a power level module comprising a first inductor, a second inductor, a first group of switching tubes and a second group of switching tubes, a first end of the first inductor is connected with a first switching node, a second end of the first inductor is connected with a second switching node, the first group of switching tubes are arranged between a first power supply input end and a plurality of positive power supply output ends, and the second group of switching tubes are arranged between a second power supply input end and a plurality of negative power supply output ends; the first end of the second inductor is connected with the second reference ground, the second end of the second inductor is connected with the third switching node, and the second group of switching tubes are arranged between the second power supply input end and the negative power supply output end; and the logic control module is used for controlling the first group of switch tubes or the second group of switch tubes. According to the power supply circuit, the negative power supply voltage can be generated without using a negative voltage charge pump in the circuit, so that the power supply circuit can be suitable for relatively wide input and output voltage ranges and has extremely high practicability and compatibility.

Description

Technical Field

[0001] The present invention relates to the technical field of power supply circuits, and in particular to a power supply circuit and an AMOLED display device. Background Art

[0002] Power supply is an important component of electronic products. Using fewer power supplies in electronic products to simplify power supply requirements is the current technological trend. However, in some special electronic applications, multiple power supplies are required, especially in some applications, positive and negative power supplies must be used at the same time.

[0003] Electronic applications that use both positive and negative power supplies include: the local interface circuit of traditional telephones, liquid crystal display, OLED (Organic Light-Emitting Diode) display, CCD (Charge Coupled Device) bias, power amplifier circuits, and the front-end part of analog input of instruments and meters. Except for the front-end analog part of instruments and meters, the others are large-scale power supply applications, and a large number of specialized mature commercial products have appeared. Due to the special requirements of the test for the front-end analog part of instruments and meters, a combination of discrete power supply circuits is generally used to realize positive and negative power supplies.

[0004] Compared with traditional LCD panels, active matrix organic light-emitting diode (AMOLED) display panels have the characteristics of faster response speed, higher contrast, and wider viewing angle. They have been widely used in smart bracelets, smart watches, smart phones, tablets, laptops, etc.

[0005] In the application of smart bracelets, smart watches or smart phones, the power circuit of the AMOLED display panel generally needs to provide at least three power supplies, namely ELVDD, ELVSS and AVDD. ELVDD and ELVSS are the LED power supplies in the AMOLED display panel, and AVDD is the analog power supply provided to the display driver chip. The display driver chip converts AVDD into the gate drive power supply VGH and VGL of the transistor (TFT) in the AMOLED display panel.

[0006] Most existing power chips or power circuits (such as AMOLED power) use independent boost power converters to provide power AVDD. The typical application is to boost a single lithium battery to around 7.3V. In smart bracelets or smart watches, 2.8V to 3.3V is used as the system power supply. The AVDD power supply is generally directly taken from the lithium battery voltage and output after being stabilized by LDO (Low Dropout Regulator), or taken from the common high-voltage power supply of power AVDD, ELVDD and ELVSS and then output after being stabilized by LDO. Both methods have certain disadvantages.

[0007] For the first solution, the circuit efficiency is very low when the battery discharge voltage is high (for example, 4.4V). Moreover, for batteries such as silicon negative electrode batteries whose discharge voltage can reach 2V to 2.5V, it is far from meeting the LDO output requirement of 2.8V to 3.3V, and has great limitations.

[0008] For the second option, Figure 1 As shown, in the existing power supply circuit 100 for AMOLED display panels, the (boost type or buck-boost type) DC-DC converter 110 based on the inductor structure multiplies or bucks the voltage connected to the power input terminal VIN to near the required voltage, and generates an intermediate node voltage VOP whose absolute voltage is slightly higher than the output positive voltage and the output negative voltage. The intermediate node voltage VOP generates positive voltage power supplies ELVDD and AVDD after passing through LDO 120 and 130, and uses a negative voltage charge pump ((Negative Voltage Charge Pump)) 140 and LDO 150 to generate an output negative voltage power supply ELVSS. The main disadvantage of this solution is that the common node power supply VOP needs to be higher than the one with the highest absolute value voltage among AVDD, ELVDD and ELVSS. If the absolute values ​​of these three voltages are greatly different, the efficiency of the lower power rail will be reduced. Summary of the invention

[0009] In order to solve the above technical problems, the present invention provides a power supply circuit and an AMOLED display device, which can generate a negative power supply voltage without using a negative voltage charge pump in the circuit, so it can be applicable to a wider input and output voltage range and has extremely high practicality and compatibility.

[0010] According to one aspect of the present invention, there is provided a power supply circuit, which is applied to an AMOLED display device, and includes: a power stage module, which includes a first inductor, a second inductor, a first group of switch tubes and a second group of switch tubes, wherein the first end of the first inductor is connected to a first switching node, the second end of the first inductor is connected to a second switching node, the first group of switch tubes is arranged between a first power input terminal and a plurality of positive power output terminals, the first end of the second inductor is connected to a second reference ground, the second end of the second inductor is connected to a third switching node, and the second group of switch tubes is arranged between the second power input terminal and a negative power output terminal; and a logic control module, which is used to control the conduction and shutdown of the first group of switch tubes or the second group of switch tubes, so that the first inductor or the second inductor is charged or discharged, so as to provide an output voltage at the plurality of positive power output terminals or the negative power output terminal, wherein the output voltage of the negative power output terminal is a negative voltage.

[0011] Optionally, the first group of switch tubes includes first to fifth switch tubes, and the control ends of the first to fifth switch tubes are connected to the logic control module, wherein the first end of the first switch tube is connected to the first power supply input end, the second end of the first switch tube is connected to the first switching node, the first end of the second switch tube is connected to the first switching node, the second end of the second switch tube is connected to the first reference ground, the first end of the third switch tube is connected to the second switching node, the second end of the third switch tube is connected to the first reference ground, the first end of the fourth switch tube is connected to the first positive power supply output end, and the second end of the fourth switch tube is connected to the second switching node; the first end of the fifth switch tube is connected to the second positive power supply output end, and the second end of the fifth switch tube is connected to the second switching node.

[0012] Optionally, the second group of switch tubes includes a sixth and a seventh switch tube, and the control ends of the sixth and seventh switch tubes are connected to the logic control module, wherein the first end of the sixth switch tube is connected to the second power supply input end, the second end of the sixth switch tube is connected to the third switching node, the first end of the seventh switch tube is connected to the third switching node, and the second end of the seventh switch tube is connected to the negative power supply output end.

[0013] Optionally, the first group of switch tubes uses the first inductor in a time division multiplexing manner to provide output voltages of the multiple positive power supply output terminals.

[0014] Optionally, the logic control module is used to divide the entire switching cycle into multiple time slices, and control the on and off of a number of switch tubes in the first group of switch tubes in corresponding time slices to provide an independent output voltage at each of the multiple positive power supply output terminals.

[0015] Optionally, the multiple time slices include a first and a second time slice, and the logic control module is used to control the first switch tube, the second switch tube, the third switch tube and the fourth switch tube to be turned on and off in the first time slice to form a first buck-boost converter, and the logic control module is used to control the first switch tube, the second switch tube, the third switch tube and the fifth switch tube to be turned on and off in the second time slice to form a second buck-boost converter.

[0016] Optionally, the time lengths of the first and second time slices are set by the size of the load connected to the corresponding power supply output terminal.

[0017] Optionally, the logic control module includes: a feedback compensation unit, used to compare the output voltages of the first positive power supply output terminal, the second positive power supply output terminal and the negative power supply output terminal with corresponding reference voltages, thereby generating multiple error signals; a time-sharing control unit, used to provide switch control signals to the multiple switch tubes through logic control according to the multiple error signals; and a driving unit, used to provide drive signals to the multiple switch tubes according to the switch control signals.

[0018] Optionally, the power supply circuit further includes: a plurality of low voltage dropout linear regulators arranged at the first positive power supply output terminal, the second positive power supply output terminal and the negative power supply output terminal.

[0019] Optionally, the first switch tube, the fourth switch tube, the fifth switch tube and the sixth switch tube are PMOS transistors, and the second switch tube, the third switch tube and the seventh switch tube are NMOS transistors.

[0020] Optionally, the first power input terminal and the second power input terminal are short-circuited together to serve as a common power input terminal.

[0021] According to another aspect of the present invention, an AMOLED display device is provided, comprising: an AMOLED display panel; a driving circuit for driving light-emitting elements on the AMOLED display panel; and the above-mentioned power supply circuit, wherein the power supply circuit is used to provide multiple output voltages to the driving circuit.

[0022] In summary, the power supply circuit for an AMOLED display device provided by the embodiment of the present invention uses dual power inductors and multiple switching tubes to generate the positive power supply voltage and the negative power supply voltage required by the driving circuit. Therefore, the output voltage of the circuit can be applicable to a wider input voltage range, and the output voltages are also independent of each other and can be adjusted arbitrarily. Therefore, the practicality and compatibility of the AMOLED display device using the power supply circuit can be greatly improved.

[0023] In addition, the power supply circuit of the embodiment of the present invention uses a first inductor and a first group of switch tubes to generate the required positive power supply voltage, and uses a second inductor and a second group of switch tubes to generate the required negative power supply voltage, so that the positive voltage device and the negative voltage device can be independent of each other. Compared with the single inductor multi output circuit (SIMO for short), the size of the power inductor can be significantly reduced, so it is easier to implement when used in application scenarios such as smart watches and smart bracelets that are sensitive to the size of the inductor. In addition, the switch tube of the embodiment of the present invention does not need to have a very high voltage resistance performance, so the size is smaller, which can significantly reduce the size and cost of the circuit and improve the light load efficiency of the circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The above and other objects, features and advantages of the present invention will become more apparent through the following description of the embodiments of the present invention with reference to the accompanying drawings.

[0025] Figure 1 A schematic structural diagram of a power supply circuit for an AMOLED display device according to the prior art is shown.

[0026] Figure 2 A schematic structural diagram of a power supply circuit for an AMOLED display device according to a first embodiment of the present invention is shown.

[0027] Figure 3 A schematic structural diagram of a power supply circuit for an AMOLED display device according to a second embodiment of the present invention is shown.

[0028] Figure 4 A schematic diagram of the chip structure of a power supply circuit according to an embodiment of the present invention is shown.

[0029] Figure 5 A schematic structural diagram of a power supply control system applied to an AMOLED display device according to an embodiment of the present invention is shown.

[0030] Figure 6 Show Figure 5 Schematic diagram of the driving circuit in . DETAILED DESCRIPTION

[0031] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present invention are given in the drawings. However, the present invention can be implemented in different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the content of the present invention more thorough and comprehensive.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The present invention is described in detail below with reference to the accompanying drawings.

[0033] In all embodiments of the present invention, since the source and drain of the metal oxide semiconductor (MOS) transistor are symmetrical, and the conduction current directions between the source and drain of the N-type transistor and the P-type transistor are opposite, in the embodiments of the present invention, the controlled middle pole of the MOS transistor is referred to as the control terminal, and the other two ends of the MOS transistor are referred to as the first terminal and the second terminal, respectively. For the convenience of unified expression, in the context, the source, drain and gate of the PMOS transistor are referred to as the first terminal, the second terminal and the control terminal, respectively, and the drain, source and gate of the NMOS transistor are referred to as the first terminal, the second terminal and the control terminal, respectively. In addition, the PMOS and NMOS in the circuit of the invention only represent a switch MOSFET. In actual use, the PMOS can also be replaced with a smaller NMOS and matched with a corresponding drive circuit to achieve the same circuit effect.

[0034] Figure 2 FIG. 2 is a schematic diagram showing a structure of a power supply circuit for an AMOLED display device according to a first embodiment of the present invention. Figure 2 As shown, the power supply circuit 200 includes a power stage module 210 and a logic control module 220. The power stage module 210 includes a first inductor L1, a second inductor L2, a first group of switch tubes (for example, switch tubes FET1 to FET3, FETA and FETP) and a second group of switch tubes (for example, switch tubes FET6 and FET7). The first end of the first inductor L1 is connected to the first switching node SW1, the second end of the inductor L1 is connected to the second switching node SW2, the first group of switch tubes is arranged between the first power input terminal PVIN1 and a plurality of positive power output terminals (for example, positive power output terminals AVDD and ELVDD), the first end of the second inductor L2 is connected to the second reference ground PGND2, the second end of the second inductor L2 is connected to the third switching node SW3, and the second group of switch tubes is arranged between the second power input terminal PVIN2 and the negative power output terminal ELVSS. The logic control module 220 is used to control the on and off of the first group of switch tubes or the second group of switch tubes, so that the first inductor L1 or the second inductor L2 is charged or discharged, so as to provide output voltages at the multiple positive power output terminals AVDD and ELVDD and the negative power output terminal ELVSS. The output voltage of the negative power output terminal ELVSS is a negative voltage.

[0035] Further, the switch tube FET1 is, for example, a PMOS transistor, a first end of which is connected to the first power input terminal PVIN1, and a second end of which is connected to the first switching node SW1. The switch tube FET2 is, for example, an NMOS transistor, a first end of which is connected to the first switching node SW1, and a second end of which is connected to the first reference ground PGND1. The switch tube FET3 is, for example, an NMOS transistor, a second end of which is connected to the first reference ground PGND1, and a first end of which is connected to the second switching node SW2. The switch tube FETA is, for example, a PMOS transistor, a second end of which is connected to the second switching node SW2, and a first end of which is connected to the positive power output terminal AVDD. The switch tube FETP is, for example, a PMOS transistor, a second end of which is connected to the second switching node SW2, and a first end of which is connected to the positive power output terminal ELVDD. The switch tube FET6 is, for example, a PMOS transistor, a first end of which is connected to the second power input terminal PVIN2, and a second end of which is connected to the third switching node SW3. The switch tube FET7 is, for example, an NMOS transistor, a first end of which is connected to the third switching node, and a second end of which is connected to the negative power output terminal ELVSS.

[0036] Furthermore, the first group of switches uses the first inductor L1 in a time-division multiplexing manner to provide output voltages of the positive power output terminals AVDD and ELVDD, and the second group of switches uses the second inductor L2 to provide output voltages of the negative power output terminal ELVSS.

[0037] Furthermore, the control ends of the first group of switch tubes and the second group of switch tubes of the power stage module 210 are connected to the logic control module 220, and the logic control module 220 is used to divide the entire switching cycle into multiple time slices, and control the conduction and shutdown of a number of switch tubes in the first group of switch tubes within the corresponding time slices to provide an independent output voltage at each of the multiple positive power supply output ends.

[0038] Further, the logic control module 220 divides the entire switching cycle into a first and a second time slice. The logic control module 220 is used to control the switch tube FETP to be in an off state in the first time slice, and then control the switch tubes FET1, FET2, FET3 and FETA to be turned on and off, and generate the output voltage at the power output terminal AVDD by controlling the first buck-boost converter composed of the switch tubes FET1, FET2, FET3 and FETA and the first inductor L1. The logic control module 220 is used to control the switch tube FETA to be in an off state in the second time slice, and then control the switch tubes FET1, FET2, FET3 and FETP to be turned on and off, and generate the output voltage at the power output terminal ELVDD by controlling the second buck-boost converter composed of the switch tubes FET1, FET2, FET3 and FETP and the first inductor L1.

[0039] Furthermore, the control of the switch tubes FET6 and FET7 by the logic control module 220 is relatively independent of the multiple switch tubes in the first group of switch tubes. The logic control module 220 is also used to control the on and off of the switch tubes FET6 and FET7 at the appropriate time of the switching cycle, and generate the output voltage at the power output terminal ELVSS through the negative voltage step-up and step-down (inverting Buck-Boost) converter composed of the switch tubes FET6 and FET7 and the second inductor L2. It should be noted that the output sequence of the multiple power output terminals in the above embodiment is only exemplary, and the output sequence of the multiple power output terminals in the present invention is not limited to the above embodiment.

[0040] Furthermore, the time length of each of the first and second time slices in this embodiment can be set by the logic control module 220 according to the size of the load connected to the corresponding power output terminal.

[0041] Furthermore, the logic control module 220 includes a feedback compensation unit 221 , a time-sharing control unit 222 and a driving unit 223 .

[0042] The feedback compensation unit 221 is used to compare the output voltages of the multiple power supply output terminals with the corresponding reference voltages to generate multiple error signals. For example, the feedback compensation unit 221 may include multiple error amplifiers EA1 to EA3, each error amplifier is used to compare the output voltage of the corresponding power supply output terminal with the corresponding reference voltage to generate an error signal. For example, the error amplifier EA1 compares the output voltage AVDD with the reference voltage V REFA The error amplifier EA2 compares the output voltage ELVDD with the reference voltage VREFP The error amplifier EA3 compares the output voltage ELVSS with the reference voltage V REFN The time-sharing control unit 222 is used to generate a plurality of switch control signals S1 to S7 and SP and SN according to the plurality of error signals Vea1 to Vea3 and the set control logic. The driving unit 223 is used to control the on and off of the first group of switch tubes and the second group of switch tubes in the power stage module 210 according to the plurality of switch control signals S1 to S7 and SP and SN, so as to adjust the output voltages AVDD, ELVDD and ELVSS to the set voltage values.

[0043] Figure 3 A schematic diagram of the structure of a power supply circuit for an AMOLED display device according to a second embodiment of the present invention is shown. In some applications, the ripple requirements for the output voltages AVDD, ELVDD, and ELVSS are relatively high, or the area of ​​the voltage-stabilizing capacitor outside the power supply circuit is required to be relatively small. Therefore, in these applications, a low-dropout linear regulator (LDO) is required to be provided inside the power supply circuit to suppress the ripple voltage of the output voltage. It is known that the low-dropout linear regulator has low cost, low noise, and low quiescent current, which are its outstanding advantages, and it requires few external components and has low losses. Figure 3 As shown, the power supply circuit 300 includes a plurality of intermediate node voltage terminals VOA, VOP and VON, which are the output voltages of the first buck-boost converter, the second buck-boost converter and the negative voltage buck-boost converter, respectively. In addition, the power supply circuit 300 also includes a plurality of LDOs 331 to 333, wherein the LDOs 331 to 333 are respectively arranged between the intermediate node voltage terminals VOA, VOP and VON and the power output terminals AVDD, ELVDD and ELVSS. In addition, the power stage module 310 and the logic control module 320 of this embodiment are exactly the same as those of the first embodiment, and are not described in detail here.

[0044] Figure 4 FIG. 2 shows a schematic diagram of a chip structure of a power supply circuit according to an embodiment of the present invention. Figure 3Taking the power supply circuit 300 in FIG. 1 as an example, the power supply circuit of the embodiment of the present invention integrates the power stage module 310 and the logic control module 320 in the same chip, and integrates the inductor L1 outside the chip. The chip includes a first power input pin PVIN1, a second power input pin PVIN2, a first switching pin SW1, a second switching pin SW2, a third switching pin SW3, a first ground pin PGND1, a second ground pin PGND2, intermediate node pins VOA, VOP and VON, and power output pins AVDD, ELVDD and ELVSS. Among them, the first power input pin PVIN1 and the second power input pin PVIN2 are used to connect to the battery voltage V BAT The power supply circuit of this embodiment further includes an input capacitor Cin connected between the power input pin VIN and the ground, a first inductor L1 and a second inductor L2 are connected outside the chip, and the first inductor L1 is connected to the first switching pin SW1 and the second switching pin SW2, the second inductor L2 is connected to the second ground pin PGND2 and the third switching pin SW3, the first ground pin PGND1 and the second ground pin PGND2 are used to be connected to the reference ground, and the intermediate node pins VOA, VOP and VON are respectively used to connect to the voltage stabilizing capacitor C outside the chip. OA , C OP and C ON The power output pins AVDD, ELVDD and ELVSS are respectively used to connect to the voltage stabilizing capacitors Cout1, Cout2 and Cout3 outside the chip.

[0045] It can be understood that in some other embodiments, in the chip for the power supply circuit 200, the intermediate node pins VOA, VOP and VON and the voltage stabilizing capacitors C connected thereto can be OA , C OP and C ON The present invention does not limit this.

[0046] Figure 5 FIG. 2 is a schematic diagram showing a structure of a power supply control system applied to an AMOLED display device according to an embodiment of the present invention. Figure 5As shown, the power supply control system 10 includes a power supply circuit 400 and a driving circuit 500. The power supply circuit 400 can be implemented by the power supply circuits 200 and 300 of the above embodiments, and provides voltage signals AVDD, ELVDD and ELVSS to the driving circuit 500. The driving circuit 500 generates a scan signal SCAN (not shown in the figure) of the AMOLED display panel based on the voltage signal AVDD, and the voltage obtained by the driving circuit 500 based on the voltage signal ELVDD is the positive voltage of the organic light-emitting component of the AMOLED display panel, and the voltage obtained by the driving circuit 500 based on the voltage signal ELVSS is the negative voltage of the organic light-emitting component of the AMOLED display panel.

[0047] Figure 6 Show Figure 5 Schematic diagram of the driving circuit in . Figure 6 The driving circuit 500 is a relatively mature circuit product in the prior art, and is described here for comprehension, for example, including: a transistor T1, a transistor T2, a transistor T3, a transistor T4, a transistor T5 and a transistor T6, as well as a storage capacitor Cst and a light-emitting element DLE.

[0048] The first end of the transistor T1 is connected to the data signal DATA, and the second end is connected to the transistor T2. Figure 4 The power output terminal ELVDD of the power circuit 400 is connected to the control terminal of the (n)th level scan signal SCAN[n]. It can be understood that the (n)th level scan signal SCAN[n] can be generated by the voltage signal AVDD through the charge pump boost circuit.

[0049] The transistor T3, the transistor T4 and the light emitting element DLE are connected in series between the connection node of the transistor T1 and the transistor T2 and the power output terminal ELVSS of the power circuit 400, and the control terminal of the transistor T4 and the control terminal of the transistor T2 are commonly connected to the (n)th stage enable signal EM[n];

[0050] The storage capacitor Cst and the transistor T5 are connected in series, and the positive electrode of the storage capacitor Cst is connected to the power output terminal ELVDD of the power circuit 400, and the negative electrode is connected to the first end of the transistor T5. The control end of the transistor T5 is connected to the (n-1)th level scan signal SCAN[n-1], and the second end receives the low level Vint;

[0051] The first end of the transistor T6 is connected to the control end of the transistor T3 , the second end is connected to the second end of the transistor T3 , and the control end is connected to the control end of the transistor T1 .

[0052] Furthermore, the aforementioned display panel is an active matrix organic light emitting diode panel (AMOLED), and the aforementioned light emitting element DLE is a light emitting diode.

[0053] Furthermore, the aforementioned transistors T1, T2, T3, T4, T5 and T6 are all PMOS thin film transistors. Specifically, transistor T3 is a driver thin film transistor (Driver TFT), and transistor T1 is a switch thin film transistor (Switch TFT). The remaining transistor combinations are used as compensation circuits to compensate for the change in the driving current of the driving light-emitting element DLE caused by the drift of the threshold voltage of the driving thin film transistor T3 on the one hand, and to stabilize the potential of the gate of the driving thin film transistor T3 on the other hand, thereby stabilizing the driving current of the driving element DLE generated by the driving circuit 500. The stability of the driving current of the light-emitting element DLE will not affect the luminous brightness of the light-emitting element DLE, thereby improving the image quality of the display panel to which the driving circuit 500 is applied.

[0054] In summary, the power supply circuit for an AMOLED display device provided by the embodiment of the present invention uses dual power inductors and multiple switching tubes to generate the positive power supply voltage and the negative power supply voltage required by the driving circuit. Therefore, the output voltage of the circuit can be applicable to a wider input voltage range, and the output voltages are also independent of each other and can be adjusted arbitrarily. Therefore, the practicality and compatibility of the AMOLED display device using the power supply circuit can be greatly improved.

[0055] In addition, the power supply circuit of the embodiment of the present invention uses a first inductor and a first group of switch tubes to generate the required positive power supply voltage, and uses a second inductor and a second group of switch tubes to generate the required negative power supply voltage, so that the positive voltage device and the negative voltage device can be independent of each other. Compared with the single inductor multi output circuit (SIMO for short), the size of the power inductor can be significantly reduced, so it is easier to implement when used in application scenarios such as smart watches and smart bracelets that are sensitive to the size of the inductor. In addition, the switch tube of the embodiment of the present invention does not need to have a very high voltage resistance performance, so the size is smaller, which can significantly reduce the size and cost of the circuit and improve the light load efficiency of the circuit.

[0056] Therefore, the power supply circuit provided by each embodiment of the present invention and the display panel and display device having the power supply circuit have extremely high practicality and compatibility, and are suitable for popularization and application.

[0057] It should be noted that it will be understood by those skilled in the art that the words "during", "when" and "when..." used in this article in connection with the operation of the circuit are not strict terms indicating an action that occurs immediately when the start-up action begins, but that there may be some small but reasonable delay or delays between it and the reaction action initiated by the start-up action, such as various transmission delays, etc. The words "approximately" or "substantially" used in this article mean that the element value has a parameter that is expected to be close to the declared value or position. However, as is well known in the art, there are always slight deviations that make it difficult for the value or position to be strictly the declared value. It has been properly determined in the art that a deviation of at least ten percent (10%) (for semiconductor doping concentrations, at least twenty percent (20%)) is a reasonable deviation from the accurate ideal target described. When used in conjunction with a signal state, the actual voltage value or logic state (e.g., "1" or "0") of the signal depends on whether positive logic or negative logic is used.

[0058] In addition, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0059] According to the embodiments of the present invention as described above, these embodiments do not describe all the details in detail, nor do they limit the invention to the specific embodiments described. Obviously, many modifications and changes can be made based on the above description. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can make good use of the present invention and the modified use based on the present invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A power supply circuit, applied to an AMOLED display device, comprising: A power stage module, comprising a first inductor, a second inductor, a first group of switch tubes and a second group of switch tubes, wherein a first end of the first inductor is connected to a first switching node, a second end of the first inductor is connected to a second switching node, the first group of switch tubes is arranged between a first power input terminal and a plurality of positive power output terminals, a first end of the second inductor is connected to a second reference ground, a second end of the second inductor is connected to a third switching node, and the second group of switch tubes is arranged between a second power input terminal and a negative power output terminal; as well as a logic control module, configured to control the on and off of the first group of switch tubes or the second group of switch tubes, so that the first inductor or the second inductor is charged or discharged, so as to provide an output voltage at the plurality of positive power output terminals or the negative power output terminals, Wherein, the output voltage of the negative power supply output terminal is a negative voltage.

2. The power supply circuit according to claim 1, wherein: The first group of switch tubes includes first to fifth switch tubes, and the control ends of the first to fifth switch tubes are connected to the logic control module. The first end of the first switch tube is connected to the first power input end, and the second end of the first switch tube is connected to the first switching node. A first end of the second switch tube is connected to the first switching node, and a second end of the second switch tube is connected to the first reference ground. A first end of a third switch tube is connected to the second switching node, and a second end of the third switch tube is connected to the first reference ground. A first end of the fourth switch tube is connected to the first positive power supply output end, and a second end of the fourth switch tube is connected to the second switching node; A first end of the fifth switch tube is connected to the second positive power supply output end, and a second end of the fifth switch tube is connected to the second switching node.

3. The power supply circuit according to claim 2, wherein: The second group of switch tubes includes a sixth switch tube and a seventh switch tube, and the control ends of the sixth switch tube and the seventh switch tube are connected to the logic control module. Wherein, a first end of the sixth switch tube is connected to the second power input end, and a second end of the sixth switch tube is connected to the third switching node. A first end of the seventh switch tube is connected to the third switching node, and a second end of the seventh switch tube is connected to the negative power supply output end.

4. The power supply circuit according to claim 3, wherein: The first group of switch tubes uses the first inductor in a time division multiplexing manner to provide output voltages of the multiple positive power supply output terminals.

5. The power supply circuit according to claim 4, wherein: The logic control module is used to divide the entire switching cycle into multiple time slices, and control the on and off of a number of switch tubes in the first group of switch tubes in corresponding time slices to provide an independent output voltage at each of the multiple positive power supply output terminals.

6. The power supply circuit according to claim 5, wherein: The plurality of time slices include first and second time slices, The logic control module is used to control the first switch tube, the second switch tube, the third switch tube and the fourth switch tube to be turned on and off in a first time slice to form a first buck-boost converter. The logic control module is used to control the first switch tube, the second switch tube, the third switch tube and the fifth switch tube to be turned on and off in a second time slice to form a second buck-boost converter.

7. The power supply circuit according to claim 6, wherein: The time lengths of the first and second time slices are set by the size of the load connected to the output terminal of the corresponding power supply.

8. The power supply circuit according to claim 5, wherein: The logic control module comprises: a feedback compensation unit, configured to compare output voltages of the first positive power output terminal, the second positive power output terminal and the negative power output terminal with corresponding reference voltages, thereby generating a plurality of error signals; A time-sharing control unit, configured to provide switch control signals for the plurality of switch tubes through logic control according to the plurality of error signals; and A driving unit is used to provide a driving signal to the plurality of switch tubes according to the switch control signal.

9. The power supply circuit according to claim 5, wherein: Also includes: A plurality of low voltage drop linear regulators are arranged at the first positive power output terminal, the second positive power output terminal and the negative power output terminal.

10. The power supply circuit according to claim 3, wherein: The first switch tube, the fourth switch tube, the fifth switch tube and the sixth switch tube are PMOS transistors, The second switch tube, the third switch tube and the seventh switch tube are NMOS transistors.

11. The power supply circuit according to claim 2 or 3, wherein: The first power input terminal and the second power input terminal are short-circuited together to serve as a common power input terminal.

12. An AMOLED display device, comprising: AMOLED display panel; A driving circuit, used to drive the light-emitting elements on the AMOLED display panel; as well as The power supply circuit according to any one of claims 1 to 11, wherein the power supply circuit is used to provide multiple output voltages to the drive circuit.

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