Voltage conversion circuit and method thereof, power management device, and display apparatus

Abstract

Embodiments of the present application relate to a voltage conversion circuit and method thereof, a power management device and a display device. The voltage conversion circuit comprises a DC-DC converter configured to perform a boost conversion on an input voltage to output a target voltage, the DC-DC converter being configured with three operating modes, i.e., a synchronous mode, a semi-synchronous mode and an asynchronous mode, the voltage increment ranges of the three operating modes being different, the voltage increment being a difference between the target voltage and the input voltage; and a controller connected to the DC-DC converter, configured to control the DC-DC converter to switch from the synchronous mode to the semi-synchronous mode when the input voltage increases to a first threshold voltage, and to control the DC-DC converter to switch from the semi-synchronous mode to the asynchronous mode when the input voltage increases to a second threshold voltage, wherein the first threshold voltage is less than the second threshold voltage.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application relate to the technical field of power supply, and in particular, to a voltage conversion circuit and method thereof, a power management device, and a display device. BACKGROUND

[0002] With the continuous development of electronic devices, electronic devices can implement more and more functions, and therefore, higher requirements are put forward for power management devices. Among them, the voltage conversion circuit for realizing the voltage boosting function is a key structure in the power management device. However, the flexibility of the current voltage conversion circuit is insufficient, and it cannot adapt to the increasingly rich functions of electronic devices. SUMMARY

[0003] Embodiments of the present application provide a voltage conversion circuit and method thereof, a power management device, and a display device, which can optimize and improve the flexibility of the voltage conversion circuit.

[0004] A voltage conversion circuit comprises:

[0005] A DC-DC converter is configured to boost convert an input voltage to output a target voltage, and is configured with three working modes of a synchronous mode, a semi-synchronous mode, and an asynchronous mode, the voltage increments of the three working modes being different, the voltage increment being a difference between the target voltage and the input voltage.

[0006] A controller is connected to the DC-DC converter, configured to control the DC-DC converter to switch from the synchronous mode to the semi-synchronous mode when the input voltage increases to a first threshold voltage, and to control the DC-DC converter to switch from the semi-synchronous mode to the asynchronous mode when the input voltage increases to a second threshold voltage, wherein the first threshold voltage is less than the second threshold voltage.

[0007] A voltage conversion method comprises:

[0008] Obtaining an input voltage of a voltage conversion circuit;

[0009] Controlling a DC-DC converter to switch from a synchronous mode to a semi-synchronous mode when the input voltage increases to a first threshold voltage;

[0010] Controlling the DC-DC converter to switch from the semi-synchronous mode to an asynchronous mode when the input voltage increases to a second threshold voltage, wherein the first threshold voltage is less than the second threshold voltage.

[0011] A power management device comprises:

[0012] a memory storing preset mode switching logic, the mode switching logic including a mapping relationship between an input voltage and an operating mode;

[0013] The voltage conversion circuit as claimed in any one of the preceding claims, wherein a controller of the voltage conversion circuit is connected to the memory, the controller being configured to acquire the mode switching logic and control the DC-DC converter to switch operating modes according to the mode switching logic and the input voltage.

[0014] A display device, comprising:

[0015] a display panel;

[0016] The power management apparatus as claimed in any one of the preceding claims, wherein the power management apparatus is configured to supply the target voltage to the display panel.

[0017] The voltage conversion circuit, the method thereof, the power management apparatus and the display device, the voltage conversion circuit comprising: a DC-DC converter configured to convert an input voltage to a target voltage, the DC-DC converter being configured with three operating modes, i.e., a synchronous mode, a semi-synchronous mode and an asynchronous mode, the three operating modes having different voltage increment ranges, the voltage increment being a difference between the target voltage and the input voltage; a controller connected to the DC-DC converter, the controller being configured to control the DC-DC converter to switch from the synchronous mode to the semi-synchronous mode when the input voltage increases to a first threshold voltage, and to control the DC-DC converter to switch from the semi-synchronous mode to the asynchronous mode when the input voltage increases to a second threshold voltage, wherein the first threshold voltage is less than the second threshold voltage. In the embodiments of the present application, by configuring the DC-DC converter with three different operating modes, the controller can determine the most appropriate operating mode according to the voltage increment between the input voltage of the voltage conversion circuit and the target voltage, thereby improving the accuracy of the output voltage of the DC-DC converter to achieve better matching between the output voltage and the target voltage, and improving the control flexibility of the voltage conversion circuit to control the DC-DC converter more flexibly according to the input voltage. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related art, the drawings needed to be used in the embodiments or the related art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative effort.

[0019] Figure 1 is a structural block diagram of a voltage conversion circuit of an embodiment;

[0020] Figure 2 Operation mode schematic diagram of a DC-DC converter of an embodiment;

[0021] Figure 3 Structure block diagram of a voltage conversion circuit of an embodiment;

[0022] Figure 4 Structure block diagram of a voltage conversion circuit of an embodiment;

[0023] Figure 5 Signal timing diagram of a DC-DC converter of an embodiment in synchronous mode;

[0024] Figure 6 Signal timing diagram of a DC-DC converter of an embodiment in semi-synchronous mode;

[0025] Figure 7 Signal timing diagram of a DC-DC converter of an embodiment in asynchronous mode;

[0026] Figure 8 Structure block diagram of a voltage conversion circuit of an embodiment;

[0027] Figure 9 Flow chart of a voltage conversion method of an embodiment;

[0028] Figure 10 Structure block diagram of a power management device of an embodiment;

[0029] Figure 11 Structure block diagram of a power management device of an embodiment.

[0030] Element number explanation:

[0031] Power management device: 10; voltage conversion circuit: 11; DC-DC converter: 100; boost module: 110; PWM regulating unit: 111; first switch unit: 112; second switch unit: 113; feedback module: 120; voltage comparator: 121; delay unit: 122; voltage dividing unit: 123; controller: 200; memory: 12; display panel: 20; battery: 30. DETAILED DESCRIPTION

[0032] In order to facilitate the understanding of the embodiments of the present application, the embodiments of the present application will be described more fully and completely by reference to the related drawings. The preferred embodiments of the present application are shown in the drawings. However, the embodiments of the present application can be realized in many different forms, and are not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the disclosure of the embodiments of the present application more thorough and complete.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which embodiments of the application belong. The terminology used in the description herein is for the purpose of describing particular embodiments only and is not intended to be limiting of embodiments of the application. As used in this description, the terms "may" and "might" include any one or all of possible combination of the outcomes. The terms "first," "second," and the like, do not denote any order, quantity, or importance, but rather are used to identify one element from another, and the "and / or" is used to include one or all possible combinations of the associated listed items.

[0034] It is to be understood that the terms "first," "second," and the like, can be used herein to describe various elements, but the elements should not be limited by these terms. The terms are only used to distinguish one element from another. For example, a first threshold voltage could be termed a second threshold voltage, and, similarly, a second threshold voltage could be termed a first threshold voltage, without departing from the scope of the present application, and the first and second threshold voltages are both threshold voltages, but they are not the same threshold voltage.

[0035] In addition, the terms "first," "second," and the like, merely mean "one," "two," and so on, unless otherwise specifically stated, and are used only to identify and distinguish one element from another. Thus, a first feature could be termed a second feature, and, similarly, a second feature could be termed a first feature without departing from the scope of the present application. The terms "and / or" and "at least one of" join a list of items, wherein at least one of the items, including alternatives, can be selected. The terms "primarily composed of" and "consisting essentially of" permit the inclusion of substances that can affect the specified characteristic(s) of a composition, solution, or article without significantly changing the essential characteristic(s) of the composition, solution, or article.

[0036] Embodiments of the present application provide a voltage conversion circuit applied to an electronic device. The electronic device can be a smartphone, a tablet computer, a game device, an augmented reality (AR) device, a notebook, a desktop computing device, a wearable device, etc. For the convenience of understanding, the electronic device is exemplified as a smartphone in the following.

[0037] Figure 1 Fig. 1 is a structural block diagram of a voltage conversion circuit 11 according to an embodiment of the present application. The voltage conversion circuit 11 is applied to an electronic device, such as a smartphone, a tablet computer, a game device, an augmented reality (AR) device, a notebook, a desktop computing device, a wearable device, etc. Figure 1 In the present embodiment, the voltage conversion circuit 11 includes a DC-DC converter 100 and a controller 200.

[0038] The DC-DC converter 100 is used to boost the input voltage to output a target voltage ELVDD. That is, the DC-DC converter 100 of this application can be understood as a boost circuit. The input voltage can be the voltage provided by a device in the electronic device that provides power, such as a battery. The input voltage changes according to the amount of charge stored in the battery. Specifically, the more charge stored in the battery, the higher the input voltage; the less charge stored in the battery, the lower the input voltage. The target voltage can be the power supply voltage of other devices in the electronic device, such as the 4.6V power supply voltage required by the display panel 20. Therefore, if the input voltage changes, the internal circuit structure and / or signals of the DC-DC converter 100 also need to change accordingly to make the output voltage of the DC-DC converter 100 more stable, thereby stabilizing the power supply voltage of other devices in the electronic device.

[0039] Figure 2 This is a schematic diagram of the operating mode of a DC-DC converter 100 according to an embodiment, with reference to... Figure 2 The DC-DC converter 100 is configured with three operating modes: synchronous mode (Sync), semi-synchronous mode (Hsync), and asynchronous mode (Async). The voltage increment ranges for these three modes differ, and the voltage increment is the difference between the target voltage and the input voltage. Specifically, the voltage increment in synchronous mode may be greater than that in semi-synchronous mode, and vice versa. For example, taking the 4.6V power supply voltage required by the display panel 20 as an example, if the voltage increment in synchronous mode is greater than 0.3V, and the current input voltage provided by the battery is 4.5V, it will be impossible to achieve the required 4.6V for the display panel 20 through voltage boosting. Therefore, it is necessary to control the DC-DC converter 100 to enter another operating mode with a smaller voltage increment, such as semi-synchronous mode, in order to output the required power supply voltage.

[0040] Continue to refer to Figure 1 and Figure 2 The controller 200 is connected to the DC-DC converter 100 and is used to control the DC-DC converter 100 to switch from the synchronous mode to the semi-synchronous mode when the input voltage increases to a first threshold voltage; and to control the DC-DC converter 100 to switch from the semi-synchronous mode to the asynchronous mode when the input voltage increases to a second threshold voltage. The first threshold voltage is less than the second threshold voltage. By adopting the above settings, the controller 200 can determine a corresponding operating mode from synchronous mode, semi-synchronous mode, and asynchronous mode based on the difference between the input voltage and the target voltage ELVDD.

[0041] In the embodiment, by configuring three different working modes for the DC-DC converter 100, the controller 200 can determine the most appropriate working mode according to the voltage increment between the input voltage of the voltage conversion circuit 11 and the target voltage to be reached. Thus, the accuracy of the output voltage of the DC-DC converter 100 can be improved to achieve better matching between the output voltage and the target voltage, so that the DC-DC converter 100 can stably output the target voltage, and the DC-DC converter 100 can be more flexibly controlled according to the input voltage, that is, the control flexibility of the voltage conversion circuit 11 as a whole is improved.

[0042] With reference to the foregoing Figure 2 In one embodiment, the controller 200 is further configured to control the DC-DC converter 100 to switch from the asynchronous mode to the synchronous mode when the input voltage decreases to less than or equal to a third threshold voltage. The third threshold voltage is less than the second threshold voltage. Alternatively, the third threshold voltage can be equal to the first threshold voltage.

[0043] It can be understood that when the battery is fully charged and continues to be used with the power adapter connected, on the one hand, the power adapter is in the connected state, and on the other hand, the user performs operations such as making and receiving calls and playing music, which causes the battery to discharge, thereby causing the power of the battery to continue to fluctuate, and further causing the output voltage of the battery (i.e., the input voltage of the DC-DC converter 100) to continue to fluctuate. Therefore, in the voltage decreasing phase, if the synchronous mode, the semi-synchronous mode and the asynchronous mode are configured, and the threshold voltage for switching from the asynchronous mode to the semi-synchronous mode is close to the voltage output by the battery when the battery is fully charged, there is a risk that the input voltage fluctuation causes the DC-DC converter 100 to frequently switch working modes. At the same time, there is a certain output voltage ripple at the moment of switching the working mode of the DC-DC converter 100, for example, 80 mv to 250 mv. If the DC-DC converter 100 only performs normal mode switching, the voltage ripple has relatively small influence on other devices. However, if the DC-DC converter 100 frequently switches working modes, the power voltage of other devices in the electronic device will fluctuate frequently, thereby causing insufficient working stability of the other devices, which greatly affects the user experience.

[0044] Specifically, taking the electronic device as a display device as an example, the display device refers to an electronic device with a display function. The battery provides an input voltage to the DC-DC converter 100, and the DC-DC converter 100 outputs a target voltage after voltage boosting. The display device includes a display panel, and the target voltage is a power voltage provided to a pixel driving circuit of the display panel. Further, the driving current of a light emitting device in the display panel satisfies the following formula:

[0045] I D =β(ELVDD-V) Data ) 2

[0046] Here, ELVDD refers to the power supply voltage provided to the display panel, V. Data This refers to the data voltage corresponding to the luminous intensity of the light-emitting device, and β is a preset coefficient. Based on the above formula, it can be seen that the driving current is positively correlated with the square of the power supply voltage. Therefore, if the power supply voltage produces ripple, the driving current will experience even more severe fluctuations. For display panels, these fluctuations can lead to problems such as screen flickering and horizontal lines.

[0047] Furthermore, as human demands for display quality increase, display panel resolution has gradually evolved from FHD (Full High Definition) to QHD (Quarter High Definition), refresh rate has increased from 60Hz to 120Hz, display panel technology has progressed from rigid screens to flexible screens, and the form of display panels has changed from flat to curved. These changes also have a significant impact on the internal circuitry of the display panel; simply put, the resistance and capacitance of the display panel have increased. Therefore, as the load of the DC-DC converter 100, the horizontal flickering lines on the display panel will become increasingly noticeable with these upgrades.

[0048] Therefore, by configuring only synchronous and asynchronous operating modes during the input voltage decrease phase, this embodiment effectively avoids the problem of frequent switching of the operating mode of the DC-DC converter 100, thereby improving the display quality of the display panel. Meanwhile, during the input voltage increase phase, since the aforementioned problem of frequent switching of operating modes typically does not occur, configuring three operating modes during this phase can improve the control flexibility of the DC-DC converter 100 and the accuracy of the output voltage.

[0049] Figure 3 This is a second block diagram of the voltage conversion circuit 11 according to one embodiment, referencing... Figure 3 In this embodiment, the DC-DC converter 100 includes a boost module 110 and a feedback module 120. The controller 200 is used to output a mode signal to the DC-DC converter 100 to control the operating mode of the DC-DC converter 100.

[0050] The input terminal of the feedback module 120 is connected to the output terminal of the boost module 110. The feedback module 120 is used to generate a feedback signal based on the output voltage of the boost module 110. The two input terminals of the boost module 110 are respectively connected to the output terminals of the controller 200 and the feedback module 120. The boost module 110 is used to adjust the output voltage to the target voltage ELVDD based on the feedback signal and the mode signal. Specifically, based on the mode signal, the internal circuit structure of the DC-DC converter 100 can be switched to control the range of voltage increments of the DC-DC converter 100. Based on the feedback signal, the output voltage of the DC-DC converter 100 can be fine-tuned within the aforementioned voltage increment range, thereby enabling the DC-DC converter 100 to output an accurate target voltage.

[0051] Figure 4 This is a third structural block diagram of a voltage conversion circuit 11 according to an embodiment, referencing... Figure 4 In this embodiment, the boost module 110 includes a PWM adjustment unit 111, a first inductor L1, a first switching unit 112, and a second switching unit 113.

[0052] One end of the first inductor L1 is used to receive the input voltage Vbat, and the other end of the first inductor L1 is connected to node A. The first inductor L1 is used to transmit the input voltage Vbat to node A and suppress voltage fluctuations at node A, thereby improving the stability of the output voltage of the boost module 110.

[0053] A first switching unit 112 has two signal terminals connected to a ground terminal and the other end of the first inductor L1, respectively. The control terminal of the first switching unit 112 is connected to one output terminal of the PWM adjustment unit 111. The first switching unit 112 is used to control the on / off state between the two signal terminals according to the first control signal. The first switching unit 112 can be a transistor, such as an NMOS transistor. When the first switching unit 112 is an NMOS transistor, the gate of the NMOS transistor is connected to one output terminal of the PWM adjustment unit 111, the source of the NMOS transistor is grounded, and the drain of the NMOS transistor is connected to node A. The NMOS transistor is used to turn on node A and the ground terminal when the first control signal is high. The NMOS transistor is also used to turn off node A and the ground terminal when the first control signal is low, thereby regulating the voltage of node A.

[0054] The second switching unit 113 has one end connected to the other end of the first inductor L1, and the other end used to output the target voltage ELVDD. The control terminal of the second switching unit 113 is connected to the other output terminal of the PWM adjustment unit 111. The second switching unit 113 is used to control the on / off state between the two signal terminals according to the second control signal. The second switching unit 113 can be a transistor, such as a PMOS transistor. When the second switching unit 113 is a PMOS transistor, the gate of the PMOS transistor is connected to the other output terminal of the PWM unit, the source of the PMOS transistor is connected to capacitor C2, and the drain of the PMOS transistor is connected to node A. The PMOS transistor is used to turn on node A and capacitor C2 when the second control signal is low, to charge capacitor C2, thereby enabling the boost circuit to output a stable voltage. The PMOS transistor is also used to turn off node A and capacitor C2 when the second control signal is high, thereby stopping the charging of capacitor C2.

[0055] The PWM adjustment unit 111 is connected to the output terminals of the controller 200 and the feedback module 120 respectively. The PWM adjustment unit 111 is used to generate a first control signal based on the feedback signal and the mode signal, and to generate a second control signal based on the feedback signal and the mode signal.

[0056] In this embodiment, by changing the level of the first control signal, the first switching unit 112 can be in a corresponding on or off state. Simultaneously, by changing the level of the second control signal, the second switching unit 113 can be in a corresponding on or off state. By coordinating the states of the first switching unit 112 and the second switching unit 113, the DC-DC converter 100 can operate in the desired mode, thereby outputting an accurate target voltage ELVDD.

[0057] Specifically, the first threshold voltage can be 4.45V. When the input voltage is less than 4.45V, the DC-DC converter 100 is in synchronous mode. Figure 5 This is a signal timing diagram of a DC-DC converter 100 in synchronous mode according to one embodiment. (Refer to reference...) Figure 4 and Figure 5When the DC-DC converter 100 is in the synchronous mode, the first control signal can be a pulse signal, and the first switching unit 112 can continuously turn on and off in response to the first control signal. Simultaneously, the second control signal can also be a pulse signal, and the second switching unit 113 can continuously turn on and off in response to the second control signal. The on / off states of the first switching unit 112 and the second switching unit 113 are opposite. For example, when the first switching unit 112 is on, the second switching unit 113 is off; when the first switching unit 112 is off, the second switching unit 113 is on. That is, the states of the first switching unit 112 and the second switching unit 113 change simultaneously, hence the name synchronous mode. By continuously switching the states of the first switching unit 112 and the second switching unit 113, the voltage at node A can be stabilized, thereby controlling the stable output of the DC-DC converter 100.

[0058] The second threshold voltage can be 4.5V. When the input voltage is less than 4.5V, the DC-DC converter 100 is in semi-synchronous mode. Figure 6 This is a signal timing diagram of a DC-DC converter 100 in semi-synchronous mode according to one embodiment. (Refer to reference...) Figure 4 and Figure 6 When the DC-DC converter 100 is in the semi-synchronous mode, when the second control signal switches from a low-level voltage to a high-level voltage, the second control signal gradually changes from the low-level voltage to the high-level voltage. It is understood that the voltage range of the semi-synchronous mode is relatively small; therefore, the semi-synchronous mode can also be understood as a transition mode between synchronous and asynchronous modes. By setting a gradual voltage change method, abrupt changes in the voltage of the second control signal can be avoided, thus resulting in relatively small ripple when switching from synchronous mode to semi-synchronous mode, and also relatively small ripple when switching from semi-synchronous mode to asynchronous mode. Therefore, after setting the semi-synchronous mode, the overall ripple generated is smaller than when switching directly from synchronous mode to asynchronous mode, which is beneficial to the stability of the output voltage.

[0059] Among them, continue to refer to Figure 6The voltage can be gradually varied using a step-like approach. Specifically, the second control signal can rise from a low-level voltage to a transition voltage, maintain the transition voltage for a first preset duration, and then rise to a high-level voltage. Similarly, the second control signal can also fall from a high-level voltage to a transition voltage, maintain the transition voltage for a second preset duration, and then fall back to a low-level voltage. The difference between the transition voltage and the high-level voltage can be 1 / 8 to 1 / 10 of the high-level voltage. For example, if the low-level voltage is 0V and the high-level voltage is 5V, the transition voltage can be 4.5V. Furthermore, the first preset duration can be equal to the second preset duration, both being half the high-level duration, thereby achieving a more stable voltage change.

[0060] When the input voltage is greater than 4.5V, the DC-DC converter 100 is in asynchronous mode. Understandably, as the input voltage Vbat increases, the voltage difference across the first inductor L1 becomes smaller, causing the first switching unit 112 and the second switching unit 113 to malfunction. Therefore, it is necessary to switch the operating mode of the DC-DC converter 100 to enable the first switching unit 112 and the second switching unit 113 to function properly.

[0061] Specifically, Figure 7 This is a signal timing diagram of a DC-DC converter 100 in asynchronous mode according to one embodiment. (Refer to reference...) Figure 4 and Figure 7 When the DC-DC converter 100 is in the asynchronous mode, the first switching unit 112 can continuously turn on and off in response to the first control signal, and the second switching unit 113 can remain off in response to the second control signal. When the second switching unit 113 is a PMOS transistor, the PMOS transistor itself has a parasitic diode D1. Therefore, when the second switching unit 113 is off, the parasitic diode D1 clamps the voltage at node A to the sum of the power supply voltage and the forward voltage drop Vf of the parasitic diode D1, thereby increasing the voltage difference across the first inductor L1, allowing the NMOS transistor of the first switching unit 112 to operate normally. The forward voltage drop Vf of the parasitic diode D1 can be, for example, 0.5V. It is understood that if the second switching unit 113 is not a PMOS transistor, other devices with voltage clamping functions can also be used to regulate the voltage at node A.

[0062] Continue to refer to Figure 4In one embodiment, the feedback module 120 includes a voltage comparator 121 and a delay unit 122. The delay unit 122 receives a reference voltage signal Vref and delays the reference voltage signal Vref. A first input terminal of the voltage comparator 121 is connected to the output terminal of the boost module 110, a second input terminal of the voltage comparator 121 is connected to the delay unit 122, and the output terminal of the voltage comparator 121 is connected to one of the input terminals of the boost module 110. Specifically, the inverting input terminal of the voltage comparator 121 is connected to the output terminal of the boost module 110, and the non-inverting input terminal of the voltage comparator 121 is connected to the delay unit 122. The voltage comparator 121 generates the feedback signal based on the output voltage and the delayed reference voltage signal Vref. The delay time of the delay unit 122 can be, for example, greater than 20 ms, thereby increasing the delay between the output terminal of the voltage comparator 121 and the reference voltage signal Vref.

[0063] It is understandable that for voltage comparator 121, increasing the delay between the reference voltage signal Vref and the output signal will reduce the sensitivity of voltage comparator 121, thereby reducing the impact of the feedback signal on the PWM adjustment unit 111, and further reducing the fluctuations of the first control signal and the second control signal. It should be noted that this embodiment does not specifically limit the type of delay unit 122; any structure with signal delay function falls within the protection scope of this embodiment. In other embodiments, the feedback module 120 including the delay unit 122 can also be applied to other voltage conversion circuits, that is, it is not limited to a DC-DC converter with three operating modes configured during the voltage rise phase, and the internal structure of the DC-DC converter is not limited to... Figure 4 Example. For instance, if the DC-DC converter is configured with two operating modes in both the voltage rise phase and the voltage fall phase, or with three operating modes respectively, the delay unit 122 of this embodiment can also perform delay processing on the signal input to the voltage comparator 121, thereby avoiding the problem of frequent mode switching and suppressing the ripple of the output voltage.

[0064] Continue to refer to Figure 4In one embodiment, the delay unit 122 includes a first resistor R1 and a first capacitor C1. One end of the first resistor R1 is connected to a first terminal of the voltage comparator 121, and the other end of the first resistor R1 is used to receive the reference voltage signal Vref. One end of the first capacitor C1 is connected to the other end of the first resistor R1, and the other end of the first capacitor C1 is grounded. Specifically, under the combined action of the first resistor R1 and the first capacitor C1, the feedback signal output by the voltage comparator 121 cannot be immediately reversed. Therefore, there is a delay between the feedback signal and the reference signal, and the delay time is determined by the first resistor R1 and the first capacitor C1. For example, if the first capacitor C1 becomes larger, the charging speed slows down, the voltage change rate on the first capacitor C1 slows down, thereby reducing the frequency of signal fluctuations and, consequently, the frequency of mode switching.

[0065] Figure 8 This is a fourth block diagram of a voltage conversion circuit 11 according to one embodiment, referencing... Figure 8 ,compared to Figure 4 In this embodiment, the boost module 110 further includes a voltage divider unit 123. Specifically, the voltage divider unit 123 includes a second resistor R2 and a third resistor R3. One end of the second resistor R2 is grounded, and the other end is connected to one end of the third resistor R3. The other end of the third resistor R3 is connected to the source of the PMOS transistor. By setting the second resistor R2 and the third resistor R3, the output voltage can be divided to reduce the voltage value transmitted to the voltage comparator 121, thereby allowing the use of a smaller reference voltage Vref, and further reducing the overall power consumption of the voltage conversion circuit 11.

[0066] Further reference Figure 8 A fourth resistor R4 can be connected in parallel between the non-inverting output terminal and the output terminal of voltage comparator 121 to form a hysteresis comparator together with voltage comparator 121, so as to avoid interference from disturbance signals and thus improve the stability and reliability of the comparator.

[0067] In one embodiment, the controller 200 includes a threshold voltage generation module and a mode selector. The threshold voltage generation module receives an input voltage Vbat and generates multiple threshold voltages, such as a first threshold voltage and a second threshold voltage. The mode selector can determine whether to switch from a synchronous mode to a semi-synchronous mode based on the first threshold voltage, and whether to switch from a semi-synchronous mode to an asynchronous mode based on the second threshold voltage.

[0068] Figure 9 Here is a flowchart of a voltage conversion method according to one embodiment, see reference. Figure 9 In this embodiment, the voltage conversion method includes steps 100 to 300.

[0069] Step 100: Obtain the input voltage of the voltage conversion circuit;

[0070] Step 200: When the input voltage increases to the first threshold voltage, the DC-DC converter 100 is controlled to switch from synchronous mode to semi-synchronous mode.

[0071] Step 300: When the input voltage increases to the second threshold voltage, control the DC-DC converter 100 to switch from the semi-synchronous mode to the asynchronous mode, wherein the first threshold voltage is less than the second threshold voltage.

[0072] The voltage conversion method of this embodiment can be applied to the controller 200 in the aforementioned voltage conversion circuit 11. Specific limitations of the voltage conversion method can be found in the above description of the limitations of the voltage conversion circuit 11, and will not be repeated here. This embodiment, through the aforementioned voltage conversion method, allows for flexible switching of the operating mode of the DC-DC converter 100, enabling the DC-DC converter 100 to output a stable and reliable target voltage, thereby improving the stability of the electronic device.

[0073] This application also provides a computer-readable storage medium. One or more non-volatile computer-readable storage media containing computer-executable instructions, which, when executed by one or more processors, cause the processors to perform the steps of a voltage conversion method.

[0074] It should be understood that, although Figure 9 The steps in the flowchart are shown sequentially as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order in which these steps are executed, and they can be performed in other orders. Figure 9 At least some of the steps in the process may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least some of the sub-steps or stages of other steps.

[0075] Figure 10 This is a structural block diagram of a power management device 10 according to an embodiment, with reference to... Figure 10 In this embodiment, the power management device 10 includes a memory 12 and a voltage conversion circuit 11 as described above.

[0076] The memory 12 stores preset mode switching logic, which includes a mapping relationship between input voltage and operating mode. The memory 12 can be an OTP (One-Time Programmable) memory. The controller 200 of the voltage conversion circuit 11 is connected to the memory 12. The controller 200 is used to acquire the mode switching logic and control the DC-DC converter 100 to switch operating modes according to the mode switching logic and the input voltage. In this embodiment, by using the OTP memory 12, flexible configuration of the mode switching logic of the DC-DC converter 100 can be achieved without modifying the circuit.

[0077] It is understood that any references to memory, databases, or other media used in this application may include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory may include random access memory (RAM), which is used as external cache memory. By way of illustration and not limitation, RAM is available in a variety of forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), RAMbus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and RAMbus dynamic RAM (RDRAM).

[0078] Figure 11 This is a structural block diagram of a power management device 10 according to an embodiment, with reference to... Figure 11 In this embodiment, the display device includes a display panel 20 and a power management device 10 as described above. Further, the display device also includes a battery 30 connected to the power management device 10, thereby providing an input voltage Vbat to the power management device 10. The power management device 10 is used to power the display panel 20 with the target voltage ELVDD. By setting the power management device 10 as described above, the display stability of the display panel 20 can be greatly improved, preventing problems such as horizontal lines, thereby improving the display quality of the display device and thus enhancing the user experience.

[0079] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0080] The above-described embodiments are merely illustrative of several implementation methods of the embodiments of this application, and their descriptions are relatively specific and detailed. However, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the embodiments of this application, and these all fall within the protection scope of the embodiments of this application. Therefore, the protection scope of the patent for the embodiments of this application should be determined by the appended claims.

Claims

1. A voltage conversion circuit, characterized in that, include: A DC-DC converter is used to boost an input voltage to output a target voltage. The DC-DC converter is configured with three operating modes: synchronous mode, semi-synchronous mode, and asynchronous mode. The voltage increment range of the three operating modes is different. The voltage increment is the difference between the target voltage and the input voltage. A controller, connected to the DC-DC converter, is configured to control the DC-DC converter to switch from the synchronous mode to the semi-synchronous mode when the input voltage increases to a first threshold voltage; and to control the DC-DC converter to switch from the semi-synchronous mode to the asynchronous mode when the input voltage increases to a second threshold voltage. The controller is further configured to control the DC-DC converter to switch from the asynchronous mode to the synchronous mode when the input voltage decreases to less than or equal to a third threshold voltage; wherein the first threshold voltage is less than the second threshold voltage, and the third threshold voltage is less than the second threshold voltage.

2. The voltage conversion circuit according to claim 1, characterized in that, The controller outputs a mode signal to the DC-DC converter to control its operating mode. The DC-DC converter includes a boost module and a feedback module. The input terminal of the feedback module is connected to the output terminal of the boost module, and the feedback module is used to generate a feedback signal based on the output voltage of the boost module. The two input terminals of the boost module are respectively connected to the output terminals of the controller and the feedback module. The boost module is used to adjust the output voltage to the target voltage according to the feedback signal and the mode signal.

3. The voltage conversion circuit according to claim 2, characterized in that, The feedback module includes a voltage comparator and a delay unit, wherein, The delay unit is used to receive a reference voltage signal and perform delay processing on the reference voltage signal; The first input terminal of the voltage comparator is connected to the output terminal of the boost module, the second input terminal of the voltage comparator is connected to the delay unit, and the output terminal of the voltage comparator is connected to one of the input terminals of the boost module. The voltage comparator is used to generate the feedback signal based on the output voltage and the delayed reference voltage signal.

4. The voltage conversion circuit according to claim 3, characterized in that, The delay unit includes: A first resistor, one end of which is connected to the first terminal of the voltage comparator, and the other end of which is used to receive the reference voltage signal; A first capacitor, one end of which is connected to the other end of the first resistor, and the other end of the first capacitor is grounded.

5. The voltage conversion circuit according to claim 2, characterized in that, The boost module includes: The PWM adjustment unit is connected to the output terminals of the controller and the feedback module respectively. The PWM adjustment unit is used to generate a first control signal based on the feedback signal and the mode signal, and to generate a second control signal based on the feedback signal and the mode signal. A first inductor, one end of which is used to receive the input voltage; The first switching unit has two signal terminals connected to the ground terminal and the other end of the first inductor, respectively. The control terminal of the first switching unit is connected to one output terminal of the PWM adjustment unit. The first switching unit is used to control the on / off state between the two signal terminals according to the first control signal. The second switching unit has one end connected to the other end of the first inductor and the other end used to output the target voltage. The control terminal of the second switching unit is connected to the other output terminal of the PWM adjustment unit. The second switching unit is used to control the on / off state between the two signal terminals according to the second control signal.

6. The voltage conversion circuit according to claim 5, characterized in that, When the DC-DC converter is in the semi-synchronous mode, when the second control signal switches from a low level voltage to a high level voltage, the second control signal gradually changes from the low level voltage to the high level voltage.

7. A voltage conversion method, characterized in that, include: Obtain the input voltage of the voltage conversion circuit; When the input voltage increases to the first threshold voltage, the DC-DC converter is controlled to switch from synchronous mode to semi-synchronous mode. When the input voltage increases to the second threshold voltage, the DC-DC converter is controlled to switch from the semi-synchronous mode to the asynchronous mode. When the input voltage decreases to less than or equal to the third threshold voltage, the DC-DC converter is controlled to switch from the asynchronous mode to the synchronous mode. Wherein, the first threshold voltage is less than the second threshold voltage, and the third threshold voltage is less than the second threshold voltage.

8. A power management device, characterized in that, include: The memory stores preset mode switching logic, which includes a mapping relationship between input voltage and operating mode. According to any one of claims 1 to 6, the voltage conversion circuit has a controller connected to the memory, and the controller is used to acquire the mode switching logic and control the DC-DC converter to switch the operating mode according to the mode switching logic and the input voltage.

9. A display device, characterized in that, include: Display panel; The power management device of claim 8, wherein the power management device is configured to supply power to the display panel at the target voltage.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the method as described in claim 7.

Images