WO2022247472A1

WO2022247472A1 - Voltage conversion circuit and method therefor, and power management apparatus and display device

Info

Publication number: WO2022247472A1
Application number: PCT/CN2022/085280
Authority: WO
Inventors: 左鸿阳; 刘磊
Original assignee: Oppo广东移动通信有限公司
Priority date: 2021-05-28
Filing date: 2022-04-06
Publication date: 2022-12-01
Also published as: CN115411938A

Abstract

A voltage conversion circuit (11), comprising: a DC-DC converter (100), which is used for performing boost conversion on an input voltage, so as to output a target voltage, wherein the DC-DC converter (100) is configured to have three working modes, i.e. a synchronous mode, a semi-synchronous mode and an asynchronous mode, and voltage increment ranges for the three working modes are different, a voltage increment being the difference between the target voltage and the input voltage; and a controller (200), which is connected to the DC-DC converter (100), and is used for, when the input voltage increases to a first threshold voltage, controlling the DC-DC converter (100) to switch from the synchronous mode to the semi-synchronous mode, and when the input voltage increases to a second threshold voltage, controlling the DC-DC converter (100) to switch from the semi-synchronous mode to the asynchronous mode, wherein the first threshold voltage is smaller than the second threshold voltage.

Description

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

Cross References to Related Applications

This application claims the priority of the Chinese patent application with the application number 2021105930064 and the title of the invention "voltage conversion circuit and its method, power management device and display device" submitted to the China Patent Office on May 28, 2021, the entire content of which is passed References are incorporated in this application.

technical field

The present application relates to the technical field of power supply, in particular to a voltage conversion circuit and its method, a power management device and a display device.

Background technique

The statements herein merely provide background information related to the present application and do not necessarily constitute exemplary techniques.

With the continuous development of electronic equipment, the electronic equipment can realize more and more functions. Therefore, higher requirements are put forward for the power management device. Among them, the voltage conversion circuit for realizing the function of voltage raising and lowering is the key structure in the power management device. However, current voltage conversion circuits are not flexible enough to adapt to the increasingly rich functions of electronic devices.

Contents of the invention

According to various embodiments of the present application, a voltage conversion circuit and method thereof, a power management device and a display device are provided.

A voltage conversion circuit comprising:

The DC-DC converter is used to step-up convert the input voltage to output the target voltage. The DC-DC converter is configured with three operating modes: synchronous mode, semi-synchronous mode and asynchronous mode. The three operating modes The range of the voltage increment is different, and the voltage increment is the difference between the target voltage and the input voltage;

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 when the input voltage increases to a second threshold voltage, control the DC-DC converter to switch from the semi-synchronous mode to the asynchronous mode, wherein the first threshold voltage is less than the second threshold voltage Voltage.

A voltage conversion method, comprising:

obtaining the input voltage of the voltage conversion circuit;

When the input voltage increases to a first threshold voltage, controlling the DC-DC converter to switch from a synchronous mode to a semi-synchronous mode;

When the input voltage increases to a second threshold voltage, the DC-DC converter is controlled to switch from the semi-synchronous mode to the asynchronous mode, wherein the first threshold voltage is smaller than the second threshold voltage.

A power management device, comprising:

The memory stores preset mode switching logic, and the mode switching logic includes a mapping relationship between the input voltage and the working mode;

As in the above-mentioned voltage conversion circuit, the controller of the voltage conversion circuit is connected to the memory, and the controller is used to obtain the mode switching logic and control the DC- The DC converter switches the operation mode.

A display device comprising:

display panel;

As in the above power management device, the power management device is configured to supply power to the display panel with the target voltage.

The details of one or more embodiments of the application are set forth in the accompanying drawings and the description below. Other features, objects and advantages of the present application will be apparent from the description, drawings and claims.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments or exemplary technologies of the present application, the following will briefly introduce the accompanying drawings that need to be used in the descriptions of the embodiments or exemplary technologies. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present application. Those skilled in the art can also obtain the drawings of other embodiments according to these drawings without creative work.

Fig. 1 is one of structural block diagrams of the voltage conversion circuit of an embodiment;

FIG. 2 is a schematic diagram of a working mode of a DC-DC converter in an embodiment;

Fig. 3 is the second structural block diagram of the voltage conversion circuit of an embodiment;

Fig. 4 is the third structural block diagram of the voltage conversion circuit of an embodiment;

FIG. 5 is a signal timing diagram when the DC-DC converter in an embodiment is in a synchronous mode;

FIG. 6 is a signal timing diagram when the DC-DC converter of an embodiment is in a semi-synchronous mode;

FIG. 7 is a signal timing diagram when the DC-DC converter in an embodiment is in an asynchronous mode;

FIG. 8 is a fourth structural block diagram of a voltage conversion circuit of an embodiment;

FIG. 9 is a flowchart of a voltage conversion method according to an embodiment;

FIG. 10 is a structural block diagram of a power management device according to an embodiment;

Fig. 11 is a structural block diagram of a display device according to an embodiment.

Component label description:

Power management device: 10; voltage conversion circuit: 11; DC-DC converter: 100; boost module: 110; PWM adjustment 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 ways

In order to facilitate understanding of the embodiments of the present application, the following will describe the embodiments of the present application more comprehensively with reference to related drawings. A preferred embodiment of the embodiments of the application is given in the accompanying drawings. However, the embodiments of the present application can be implemented in many different forms, and are not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the embodiments of the present application more thorough and comprehensive.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field of the embodiments of this application. The terms used herein in the description of the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the embodiments of the present application. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

It can be understood that the terms "first", "second" and the like used in this application may be used to describe various elements herein, but these elements are not limited by these terms. These terms are only used to distinguish one element from another element. 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. Both the first threshold voltage and the second threshold voltage are threshold voltages, but they are not the same threshold voltage.

In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be interpreted as indicating or implying relative importance or implicitly specifying the quantity of indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include at least one of these features. In the description of the present application, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined. In the description of the present application, "several" means at least one, such as one, two, etc., unless otherwise specifically defined.

The embodiment of the present application provides a voltage conversion circuit applied to an electronic device, and the electronic device can be a smart phone, a tablet computer, a game device, an augmented reality (Augmented Reality, AR) device, a notebook, a desktop computing device, a wearable device, etc. . For the convenience of understanding, the electronic device is used as an example for illustration below.

FIG. 1 is one of the structural block diagrams of a voltage conversion circuit 11 according to an embodiment. Referring to FIG. 1 , in this embodiment, the voltage conversion circuit 11 includes a DC-DC converter 100 and a controller 200 .

The DC-DC converter 100 is used to boost-convert an input voltage to output a target voltage ELVDD. That is, the DC-DC converter 100 of the present application can be understood as a boost circuit. Wherein, the input voltage may be a voltage provided by a device for providing electric energy in the electronic device, and the device for providing electric energy may be a battery, for example, and the input voltage may change according to the electric quantity stored in the battery. Specifically, the more power stored in the battery, the greater the input voltage; the less power stored in the battery, the lower the input voltage. The target voltage may be the power supply voltage of other devices in the electronic equipment, for example, the power supply voltage 4.6V required by the display panel 20 . Therefore, if the input voltage changes, the circuit structure and/or signals inside the DC-DC converter 100 also need to change accordingly, so that the output voltage of the DC-DC converter 100 is relatively stable, so that other devices in the electronic equipment The power supply voltage is stable.

FIG. 2 is a schematic diagram of the working mode of the DC-DC converter 100 of an embodiment. Referring to FIG. ) three working modes, the voltage increment ranges of the three working modes are different, and the voltage increment is the difference between the target voltage and the input voltage. Specifically, the voltage increment in the synchronous mode may be greater than that in the semi-synchronous mode, and the voltage increment in the semi-synchronous mode may be greater than that in the asynchronous mode. Exemplarily, still taking the power supply voltage 4.6V required by the display panel 20 as an example, if the voltage increment of the synchronous mode is greater than 0.3V, and the current input voltage provided by the battery is 4.5V, it is impossible to achieve display by boosting the voltage. The 4.6V required by the panel 20. Therefore, it is necessary to control the DC-DC converter 100 to enter another working mode with a smaller voltage increment, such as the semi-synchronous mode, in order to output the required power supply voltage.

Continuing to refer to FIG. 1 and FIG. 2, the controller 200 is connected to the DC-DC converter 100, and is used to control the DC-DC converter 100 to be controlled by the DC-DC converter 100 when the input voltage increases to a first threshold voltage. switching from the synchronous mode to the semi-synchronous mode; and controlling 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. Wherein, the first threshold voltage is smaller than the second threshold voltage. By adopting the above setting method, the controller 200 can determine a corresponding working mode from synchronous mode, semi-synchronous mode and asynchronous mode according to the difference between the input voltage and the target voltage ELVDD.

In this embodiment, by configuring three different working modes for the DC-DC converter 100, the controller 200 can determine the most appropriate working mode. Therefore, the accuracy of the output voltage of the DC-DC converter 100 can be improved, so that the output voltage can better match the target voltage, so that the DC-DC converter 100 can output the target voltage stably, and the input voltage can also be adjusted according to the input voltage. The DC-DC converter 100 performs more flexible control, that is, the overall control flexibility of the voltage conversion circuit 11 is improved.

Continuing to refer to FIG. 2, in one embodiment, the controller 200 is further configured to control the DC-DC converter 100 to be controlled by the asynchronous mode switch to the synchronous mode. Wherein, the third threshold voltage is smaller than the second threshold voltage. Optionally, the third threshold voltage may be equal to the first threshold voltage.

It is understandable that when the battery is fully charged and continues to be used with the power adapter plugged in, on the one hand, the power adapter is in a connected state, and on the other hand, the user's operations such as making and receiving calls and playing music will cause the battery to discharge, resulting in battery power loss. The continuous fluctuation causes the output voltage of the battery (that is, the input voltage of the DC-DC converter 100 ) to continue to fluctuate. Therefore, in the phase of voltage drop, if the three working modes of synchronous mode, semi-synchronous mode and asynchronous mode are also configured, and the threshold voltage for switching from asynchronous mode to semi-synchronous mode is relatively close to the output voltage when the battery is fully charged, there is an input Voltage fluctuations lead to the risk of frequent switching of operating modes of the DC-DC converter 100 . At the same time, there will be a certain output voltage ripple at the moment when the working mode of the DC-DC converter 100 is switched, and the voltage ripple is, for example, 80mv to 250mv. If the DC-DC converter 100 only performs normal mode switching, the impact of the voltage ripple on other devices is relatively small. However, if the DC-DC converter 100 frequently switches working modes, it will cause frequent waveguide of the power supply voltage of other devices in the electronic device, resulting in insufficient working stability of other devices, greatly affecting user experience.

Specifically, description is made by taking an electronic device as an example of a display device, and a 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 step-up processing. Wherein, the display device includes a display panel, and the target voltage is a power supply voltage provided to a pixel driving circuit of the display panel. Further, the driving current of the light emitting device in the display panel satisfies the following formula:

I _D ＝β(ELVDD-V _Data ) ²

Wherein, ELVDD refers to the power supply voltage provided to the display panel, V _Data refers to the data voltage corresponding to the luminance of the light emitting device, and β refers to a preset coefficient. Based on the above formula, it can be found that the driving current is positively related to the square of the power supply voltage. Therefore, if the power supply voltage has ripples, the driving current will have more serious fluctuation problems. For the display panel, the above fluctuations will cause problems such as flickering stripes on the display panel.

In addition, with the increasing demand of human beings for display images, the resolution of display panels has gradually developed from FHD (Full High Definition) to QHD (Quarter High Definition), and the refresh rate has increased from 60Hz to 120hz. The hard screen has developed into a soft screen, and the shape of the display panel has changed from a flat surface to a curved surface. The above changes will also have a great impact on the circuits inside the display panel. In simple terms, it can be understood that the resistance and capacitance of the display panel are further increased. Therefore, the display panel is the load of the DC-DC converter 100 , and with the above-mentioned upgrading and changes, the stripes on the display panel will become more and more obvious.

Therefore, this embodiment can effectively avoid the problem of frequent switching of the working modes of the DC-DC converter 100 by configuring only two working modes, the synchronous mode and the asynchronous mode, during the falling phase of the input voltage, thereby improving the display quality of the display panel. At the same time, during the rising stage of the input voltage, since the above-mentioned frequent switching of the working modes usually does not occur, therefore, configuring three working modes during the rising stage can improve the control flexibility of the DC-DC converter 100 and the stability of the output voltage. accuracy.

FIG. 3 is the second structural block diagram of the voltage conversion circuit 11 of an embodiment. Referring to FIG. 3 , in this embodiment, the DC-DC converter 100 includes a boost module 110 and a feedback module 120 . The controller 200 is used for outputting a mode signal to the DC-DC converter 100 to control the working mode of the DC-DC converter 100 .

The input terminal of the feedback module 120 is connected to the output terminal of the boost module 110 , and the feedback module 120 is used for generating a feedback signal according to 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 in a one-to-one correspondence, and the boost module 110 is used for according to the feedback signal and the mode signal regulating the output voltage to the target voltage ELVDD. Specifically, based on the mode signal, the internal circuit structure of the DC-DC converter 100 can be switched to control the range of the voltage increment 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, so that the DC-DC converter 100 can output an accurate target voltage.

FIG. 4 is the third structural block diagram of the voltage conversion circuit 11 of an embodiment. Referring to FIG. the second switch unit 113 .

One end of the first inductor L1 is used to receive the input voltage Vbat, the other end of the first inductor L1 is connected to the node A, the first inductor L1 is used to transmit the input voltage Vbat to the node A, and suppress the voltage fluctuation of the node A , so as to improve the stability of the output voltage of the boost module 110 .

The first switch unit 112, the two signal terminals of the first switch unit 112 are respectively connected to the ground terminal and the other end of the first inductor L1, the control terminal of the first switch unit 112 is connected to the PWM adjustment unit 111 is connected to an output terminal. The first switch unit 112 is used to control the on-off between two signal terminals according to the first control signal. Wherein, the first switch unit 112 may 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 an output end 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 conduct the node A and the ground terminal when the first control signal is at a high level. The NMOS transistor is also used to disconnect the node A from the ground terminal when the first control signal is at a low level, so as to adjust the voltage of the node A.

The second switch unit 113, one end of the second switch unit 113 is connected to the other end of the first inductor L1, the other end of the second switch unit 113 is used to output the target voltage ELVDD, the second The control terminal of the switch unit 113 is connected with the other output terminal of the PWM regulation unit 111 . The second switch unit 113 is used to control the on-off between the two signal terminals according to the second control signal. Wherein, the second switch unit 113 may be a transistor, such as a PMOS transistor. When the second switch unit 113 is a PMOS transistor, the gate of the PMOS transistor is connected to the other output end of the PWM adjustment unit, the source of the PMOS transistor is connected to the second capacitor C2, and the drain of the PMOS transistor is connected to node A. The PMOS transistor is used to turn on the node A and the second capacitor C2 to charge the second capacitor C2 when the second control signal is at a low level, so that the booster circuit can output voltage stably. The PMOS transistor is also used to disconnect the node A and the second capacitor C2 when the second control signal is at a high level, thereby stopping charging the second capacitor C2.

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

In this embodiment, by changing the level state of the first control signal, the first switch unit 112 can be in a corresponding on or off state. At the same time, by changing the level state of the second control signal, the second switch unit 113 can be in a corresponding on or off state. By matching the states of the first switch unit 112 and the second switch unit 113 , the DC-DC converter 100 can be operated in a desired working mode, thereby outputting an accurate target voltage ELVDD.

Specifically, the first threshold voltage may be 4.45V, and when the input voltage is less than 4.45V, the DC-DC converter 100 is in the synchronous mode. FIG. 5 is a signal timing diagram when the DC-DC converter 100 is in a synchronous mode according to an embodiment. Referring to FIG. 4 and FIG. 5, when the DC-DC converter 100 is in the synchronous mode, the first control signal may be a pulse signal, and the first switch unit 112 may be continuously turned on in response to the first control signal. and disconnect. Meanwhile, the second control signal can also be a pulse signal, and the second switch unit 113 can be continuously turned on and off in response to the second control signal. Wherein, the on-off states of the first switch unit 112 and the second switch unit 113 are opposite. For example, when the first switch unit 112 is turned on, the second switch unit 113 is turned off; when the first switch unit 112 is turned off, the second switch unit 113 is turned on. That is, the state of the first switch unit 112 and the state of the second switch unit 113 change at the same time, so it is called a synchronous mode. By constantly switching the states of the first switch unit 112 and the second switch unit 113 , the voltage of the node A can be stabilized, thereby controlling the stable output of the DC-DC converter 100 .

The second threshold voltage may be 4.5V, and when the input voltage is less than 4.5V, the DC-DC converter 100 is in the semi-synchronous mode. FIG. 6 is a signal timing diagram when the DC-DC converter 100 is in a semi-synchronous mode according to an embodiment. Referring to FIG. 4 and FIG. 6 together, 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 The control signal gradually changes from the low level voltage to the high level voltage. It can be understood that the voltage range of the semi-synchronous mode is small, so the semi-synchronous mode can also be understood as a transition mode between the synchronous mode and the asynchronous mode. By setting a gradual voltage change mode, sudden changes in the voltage of the second control signal can be avoided, so that the ripple generated when the synchronous mode is switched to the semi-synchronous mode is relatively small, and the ripple generated when the semi-synchronous mode is switched to the asynchronous mode Ripple is also relatively small. Therefore, after setting the semi-synchronous mode, overall, the ripple generated is smaller than when directly switching from the synchronous mode to the asynchronous mode, which is conducive to the stability of the output voltage.

Wherein, continuing to refer to FIG. 6 , the gradual change of the voltage can be realized through a stepwise change. That is, the second control signal may rise from a low-level voltage to a transition voltage, and then rise to a high-level voltage after the transition voltage remains for a first preset time period. Similarly, the second control signal may also drop from a high-level voltage to a transition voltage, and then drop to a low-level voltage after the transition voltage remains for a second preset time period. Wherein, the difference between the transition voltage and the high-level voltage may be 1/8 to 1/10 of the high-level voltage. Exemplarily, if the low-level voltage is 0V and the high-level voltage is 5V, the transition voltage may be 4.5V. Further, the first preset duration may be equal to the second preset duration, and both are 1/2 of the high level duration, so as to achieve a relatively stable voltage change.

When the input voltage is greater than 4.5V, the DC-DC converter 100 is in the asynchronous mode. It can be understood that with the continuous increase of the input voltage Vbat, the voltage difference between the two ends of the first inductor L1 is small, so that the first switch unit 112 and the second switch unit 113 cannot work normally. Therefore, it is necessary to switch the working mode of the DC-DC converter 100 so that the first switch unit 112 and the second switch unit 113 can work normally.

Specifically, FIG. 7 is a signal timing diagram when the DC-DC converter 100 is in an asynchronous mode according to an embodiment. Referring to FIG. 4 and FIG. 7, when the DC-DC converter 100 is in the asynchronous mode, the first switch unit 112 can be continuously turned on and off in response to the first control signal, and the second switch unit 113 may remain in the off state in response to the second control signal. When the second switch unit 113 is a PMOS transistor, the PMOS transistor itself has a parasitic diode D1. Therefore, when the second switch unit 113 is turned off, the parasitic diode D1 will clamp the voltage at the node A to be equal to the power supply voltage and the parasitic diode D1. The sum of the forward voltage drop Vf, so that the voltage difference between the two ends of the first inductor L1 increases, so that the NMOS transistor of the first switch unit 112 works normally. Wherein, the forward voltage drop Vf of the parasitic diode D1 may be 0.5V, for example. It can be understood that, if the second switch unit 113 is not a PMOS transistor, other devices with a voltage clamping function may also be used to regulate the voltage at the node A.

Continuing to refer to FIG. 4 , in one embodiment, the feedback module 120 includes a voltage comparator 121 and a delay unit 122 . The delay unit 122 is used for receiving the reference voltage signal Vref, and performing delay processing on the reference voltage signal Vref. The first input end of the voltage comparator 121 is connected to the output end of the boost module 110, the second input end of the voltage comparator 121 is connected to the delay unit 122, and the output of the voltage comparator 121 The terminal 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, the non-inverting input terminal of the voltage comparator 121 is connected to the delay unit 122, and the voltage comparator 121 for generating the feedback signal according to the output voltage and the delayed reference voltage signal Vref. Wherein, the delay time of the delay unit 122 may be greater than 20 ms, for example, so as to increase the delay between the output terminal of the voltage comparator 121 and the reference voltage signal Vref.

It can be understood that, for the voltage comparator 121, if the delay between the reference voltage signal Vref and the output terminal signal is increased, the sensitivity of the voltage comparator 121 will be reduced, thereby reducing the influence of the feedback signal on the PWM adjustment unit 111, Further, the fluctuation of the first control signal and the second control signal is reduced. It should be noted that, this embodiment does not specifically limit the type of the delay unit 122 , and any structure with a signal delay function falls within the scope of protection 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 configured with three operating modes in the voltage rising phase, and the DC-DC converter The internal structure is also not limited to the embodiment shown in FIG. 4 . For example, if the DC-DC converter is respectively configured with two operating modes in the voltage rising stage and the voltage falling stage, or is respectively configured with three operating modes, the delay unit 122 of this embodiment can also be used to input to the voltage comparator 121 The signal is delayed to avoid the problem of frequent mode switching, thereby suppressing the ripple of the output voltage.

Continuing to refer to FIG. 4 , in 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 the first end 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 joint action of the first resistor R1 and the first capacitor C1, the feedback signal output by the voltage comparator 121 cannot be reversed immediately, so there is a delay between the feedback signal and the reference signal, and the delay time is determined by the first resistor R1 determined by the first capacitor C1. For example, if the first capacitor C1 becomes larger, the charging speed will be slower, and the voltage change speed on the first capacitor C1 will be slower, thereby reducing the frequency of signal fluctuations and further reducing the frequency of mode switching.

FIG. 8 is a fourth structural block diagram of the voltage conversion circuit 11 of an embodiment. Referring to FIG. 8 , compared with the embodiment in FIG. 4 , in this embodiment, the boost module 110 further includes a voltage dividing unit 123 . Specifically, the voltage dividing unit 123 includes a second resistor R2 and a third resistor R3. One end of the second resistor R2 is grounded, the other end is connected to one end of the third resistor R3, and 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, so that a smaller reference voltage Vref can be used, and the voltage conversion circuit 11 can be reduced. the overall power consumption.

Further, continuing to refer to FIG. 8, a fourth resistor R4 may be connected in parallel between the non-inverting output terminal and the output terminal of the voltage comparator 121 to jointly form a hysteresis comparator with the voltage comparator 121, so as to avoid the interference of the disturbance signal, thereby improving comparator stability and reliability.

In one of the embodiments, 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 a plurality of threshold voltages, such as a first threshold voltage and a second threshold voltage. The mode selector may determine switching from synchronous mode to semi-synchronous mode based on a first threshold voltage, and determine switching from semi-synchronous mode to asynchronous mode based on a second threshold voltage.

FIG. 9 is a flowchart of a voltage conversion method according to an embodiment. Referring to FIG. 9 , in this embodiment, the voltage conversion method includes steps 100 to 300 .

Step 100, obtaining the input voltage of the voltage conversion circuit;

Step 200, when the input voltage increases to a first threshold voltage, control the DC-DC converter 100 to switch from synchronous mode to semi-synchronous mode;

Step 300, when the input voltage increases to a 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 lower than the second threshold voltage threshold voltage.

Wherein, the voltage conversion method of this embodiment can be applied to the controller 200 in the aforementioned voltage conversion circuit 11 . For specific limitations on the voltage conversion method, please refer to the above-mentioned limitation on the voltage conversion circuit 11 , which will not be repeated here. In this embodiment, the working mode of the DC-DC converter 100 can be flexibly switched through the above-mentioned voltage conversion method, so that the DC-DC converter 100 can output a stable and reliable target voltage, thereby improving the stability of the electronic device.

The embodiment of the present application also provides a computer-readable storage medium. One or more non-transitory computer-readable storage media containing computer-executable instructions that, when executed by one or more processors, cause the processors to perform the steps of the voltage conversion method.

It should be understood that although the various steps in the flow chart of FIG. 9 are shown sequentially as indicated by the arrows, these steps are not necessarily executed sequentially in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and these steps can be executed in other orders. Moreover, at least some of the steps in FIG. 9 may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily executed at the same time, but may be executed at different times. The execution of these sub-steps or stages The order is not necessarily performed sequentially, but may be performed alternately or alternately with at least a part of other steps or sub-steps or stages of other steps.

FIG. 10 is a structural block diagram of a power management device 10 according to an embodiment. Referring to FIG. 10 , in this embodiment, the power management device 10 includes a memory 12 and the above-mentioned voltage conversion circuit 11 .

The memory 12 stores preset mode switching logic, and the mode switching logic includes the mapping relationship between the input voltage and the working mode. Wherein, the memory 12 can be an OTP (One Time Programmable, 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 obtain the mode switching logic, and control the DC-DC conversion according to the mode switching logic and the input voltage The device 100 switches the working mode. In this embodiment, by using the OTP memory 12, the flexible configuration of the mode switching logic of the DC-DC converter 100 can be realized without modifying the circuit.

It will be appreciated that any reference to memory, database or other media used herein may include non-volatile and/or volatile memory. Nonvolatile memory can include read only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM), which acts as external cache memory. By way of illustration and not limitation, RAM is available in many forms such as Static RAM (SRAM), Dynamic RAM (DRAM), Synchronous DRAM (SDRAM), Double Data Rate SDRAM (DDR SDRAM), Enhanced SDRAM (ESDRAM), Synchronous Synchlink DRAM (SLDRAM), Memory Bus (Rambus) Direct RAM (RDRAM), Direct Memory Bus Dynamic RAM (DRDRAM), and Memory Bus Dynamic RAM (RDRAM).

FIG. 11 is a structural block diagram of a display device according to an embodiment. Referring to FIG. 11 , in this embodiment, the display device includes a display panel 20 and the above-mentioned power management device 10 . Further, the display device further includes a battery 30, and the battery 30 is connected to the power management device 10 so as to provide the power management device 10 with an input voltage Vbat. The power management device 10 is used for supplying power to the display panel 20 with the target voltage ELVDD. By setting the aforementioned power management device 10, the display stability of the display panel 20 can be greatly improved, horizontal stripes and other problems can be prevented, thereby improving the display quality of the display device, and further improving user experience.

The technical features of the above-mentioned embodiments can be combined arbitrarily. To make the description concise, all possible combinations of the technical features in the above-mentioned embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, should be considered as within the scope of this specification.

The above-mentioned embodiments only express several implementation modes of the embodiments of the present application, and the descriptions thereof are relatively specific and detailed, but should not be construed as limiting the scope of the patent for the invention. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the embodiments of the present application, and these all belong to the protection scope of the embodiments of the present application. Therefore, the scope of protection of the embodiment patent of this application should be based on the appended claims.

Claims

A voltage conversion circuit comprising:

The DC-DC converter is used to step-up convert the input voltage to output the target voltage. The DC-DC converter is configured with three operating modes: synchronous mode, semi-synchronous mode and asynchronous mode. The three operating modes The range of the voltage increment is different, and the voltage increment is the difference between the target voltage and the input voltage;

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 when the input voltage increases to a second threshold voltage, control the DC-DC converter to switch from the semi-synchronous mode to the asynchronous mode, wherein the first threshold voltage is less than the second threshold voltage Voltage.
According to the voltage conversion circuit according to claim 1, the controller is further configured to control the DC-DC converter to switch from the asynchronous mode to In the synchronous mode, the third threshold voltage is smaller than the second threshold voltage.
The voltage converting circuit according to claim 2, the third threshold voltage is equal to the first threshold voltage.
According to the voltage conversion circuit according to claim 1 or 2, the controller is used to output a mode signal to the DC-DC converter to control the working mode of the DC-DC converter, and the DC-DC converter includes : boost module and feedback module, where,

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 according to the output voltage of the boost module;

The two input terminals of the boost module are respectively connected to the controller and the output terminals of the feedback module in one-to-one correspondence, and the boost module is used to adjust the output according to the feedback signal and the mode signal voltage to the target voltage.
The voltage conversion circuit according to claim 4, the feedback module comprises a voltage comparator and a delay unit, wherein,

The delay unit is used for receiving a reference voltage signal, and performing 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 the boost module. connected to one of the input terminals of the voltage module, and the voltage comparator is used to generate the feedback signal according to the output voltage and the delayed reference voltage signal.
The voltage conversion circuit according to claim 5, said delay unit comprising:

a first resistor, one end of the first resistor is connected to the first end of the voltage comparator, and the other end of the first resistor is used to receive the reference voltage signal;

A first capacitor, one end of the first capacitor is connected to the other end of the first resistor, and the other end of the first capacitor is grounded.
The voltage conversion circuit according to claim 5, the feedback module further comprising:

The fourth resistor is connected between the non-inverting output terminal and the output terminal of the voltage comparator.
The voltage conversion circuit according to claim 4, the step-up module comprising:

The PWM adjustment unit is connected to the output terminals of the controller and the feedback module respectively, and the PWM adjustment unit is used to generate a first control signal according to the feedback signal and the mode signal, and to generate a first control signal according to the feedback signal and the mode signal. said mode signal generates a second control signal;

a first inductor, one end of the first inductor is used to receive the input voltage;

The first switch unit, the two signal terminals of the first switch unit are respectively connected to the ground terminal and the other end of the first inductor, the control terminal of the first switch unit is connected to an output terminal of the PWM adjustment unit connected, the first switch unit is used to control the on-off between the two signal terminals according to the first control signal;

A second switch unit, one end of the second switch unit is connected to the other end of the first inductor, the other end of the second switch unit is used to output the target voltage, the control terminal of the second switch unit Connected to the other output terminal of the PWM adjustment unit, the second switch unit is used to control the on-off between the two signal terminals according to the second control signal.
According to the voltage conversion circuit according to claim 8, the first switching unit is a transistor.
According to the voltage conversion circuit according to claim 9, the first switching unit is an NMOS transistor, the gate of the NMOS transistor is connected to an output end of the PWM adjustment unit, the source of the NMOS transistor is grounded, and the drain of the NMOS transistor is Connect with the other end of the first inductor.
The voltage conversion circuit according to claim 8, further comprising:

The second capacitor, the two ends of the second capacitor are respectively connected to the output terminal of the target voltage and the ground terminal in a one-to-one correspondence.
The voltage converting circuit according to claim 11, the second switching unit is a transistor.
According to the voltage conversion circuit according to claim 12, the second switch unit is a PMOS transistor, the gate of the PMOS transistor is connected to the other output terminal of the PWM adjustment unit, and the source of the PMOS transistor is connected to the second capacitor, The drain of the PMOS transistor is connected to the other end of the first inductor.
The voltage conversion circuit according to claim 13, the boost module further comprising:

A voltage dividing unit, the voltage dividing unit includes a second resistor and a third resistor, one end of the second resistor is grounded, the other end is connected to one end of the third resistor, and the other end of the third resistor R3 is connected to the PMOS The source connection of the tube.
According to the voltage conversion circuit according to claim 8, 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 The second control signal gradually changes from the low level voltage to the high level voltage.
According to the voltage conversion circuit according to claim 15, when the second control signal is switched from a low-level voltage to a high-level voltage, the second control signal rises from a low-level voltage to a transition voltage, and in the transition After the voltage is maintained for a first preset time period, it rises to a high-level voltage, and the transition voltage is greater than the low-level voltage and lower than the high-level voltage.
According to the voltage conversion circuit according to claim 16, the difference between the transition voltage and the high-level voltage is 1/8 to 1/10 of the high-level voltage.
A voltage conversion method, comprising:

obtaining the input voltage of the voltage conversion circuit;

When the input voltage increases to a first threshold voltage, controlling the DC-DC converter to switch from a synchronous mode to a semi-synchronous mode;

When the input voltage increases to a second threshold voltage, the DC-DC converter is controlled to switch from the semi-synchronous mode to the asynchronous mode, wherein the first threshold voltage is smaller than the second threshold voltage.
A power management device, comprising:

The memory stores preset mode switching logic, and the mode switching logic includes a mapping relationship between the input voltage and the working mode;

The voltage conversion circuit according to any one of claims 1 to 17, the controller of the voltage conversion circuit is connected to the memory, the controller is used to obtain the mode switching logic, and according to the mode switching logic and The input voltage controls the DC-DC converter to switch working modes.
A display device comprising:

display panel;

The power management device according to claim 19, wherein the power management device is configured to supply power to the display panel at the target voltage.