Electronic device and plate vibration regulating circuit

Abstract

An electronic device and a board vibration regulating circuit relate to the field of power electronics technology. The screen of the electronic device is a liquid crystal display screen, and the electronic device includes: a bias power supply integrated circuit, a load branch, and a power supply capacitor; the bias power supply integrated circuit is used to provide a negative bias voltage for the liquid crystal display panel of the screen, and the first output port of the bias power supply integrated circuit is used to output the negative bias voltage; the first end of the power supply capacitor is connected to the first output port of the bias power supply integrated circuit, and the second end of the power supply capacitor is grounded; the first end of the load branch is connected to the first output port of the bias power supply integrated circuit, and the second end of the load branch is grounded; the load branch is used to increase the load current output by the first output port of the bias power supply integrated circuit. By using this solution, the board vibration frequency of the power supply capacitor can be prevented from being within the frequency range that can be heard by the human ear, thereby preventing the user from hearing the board vibration sound, improving the user experience, and ensuring the call quality.

Description

Technical Field

[0001] The present application relates to the field of power electronics technology, and in particular to an electronic device and a plate vibration regulating circuit. Background Art

[0002] At present, liquid crystal display (LCD) is widely used in electronic devices such as mobile phones and tablet computers. On LCD screens, LCD bias power integrated circuit (IC) is generally used to provide the required positive and negative bias voltages for the LCD panel, where the positive bias voltage is generally represented by VSP and the negative bias voltage is generally represented by VSN.

[0003] The output port of VSN is generally provided with a power supply capacitor, which is used to stabilize the output voltage of VSN. The power supply capacitor will cause board vibration. When the frequency range of the board vibration is within the frequency range of sound audible to the human ear, if the user approaches the electronic device, the board vibration sound can be heard, which reduces the user's experience of using the electronic device and also affects the user's call quality. Summary of the invention

[0004] In order to solve the above problems, the present application provides an electronic device and a board vibration adjustment circuit, which can prevent users from hearing board vibration sounds, improve the user experience, and ensure call quality.

[0005] In a first aspect, the present application provides an electronic device, the screen of the electronic device is a liquid crystal display LCD, and the electronic device includes: a bias power integrated circuit, a load branch, and a power supply capacitor. The bias power integrated circuit is used to provide a negative bias voltage for the LCD panel of the screen, and the first output port of the bias power integrated circuit is used to output the negative bias voltage. The first end of the power supply capacitor is connected to the first output port of the bias power integrated circuit, and the second end of the power supply capacitor is grounded, and the power supply capacitor is used to stabilize the negative bias voltage. The first end of the load branch is connected to the first output port of the bias power integrated circuit, and the second end of the load branch is grounded. The load branch is used to increase the load current output by the first output port of the bias power integrated circuit.

[0006] In this solution, a load branch is added to the electronic device, and a load current flows through the load branch, so that the load current of the first output port of the bias power supply integrated circuit is not only the load current of the external load, but also the load current in the load branch is superimposed, which is equivalent to increasing the load current of the first output port of the bias power supply integrated circuit, so that the load regulation frequency of the charge pump circuit of the bias power supply integrated circuit is also increased accordingly. The load regulation frequency corresponds to the board oscillation frequency of the output capacitor, so the board oscillation frequency is also increased, thereby making the board oscillation frequency of the power supply capacitor not within the frequency range audible to the human ear, avoiding users from hearing board vibration sound, improving user experience, and ensuring call quality.

[0007] In a possible implementation, the load branch includes a resistor. A first end of the resistor is connected to a first end of the load branch, and a second end of the resistor is connected to a second end of the load branch. In this implementation, the circuit structure of the load branch is simple and the hardware cost is low.

[0008] In a possible implementation, the load branch includes: a resistor and a controllable switch. The first end of the controllable switch is connected to the first end of the load branch, the second end of the controllable switch is connected to the first end of the resistor, and the second end of the resistor is connected to the second end of the load branch. In this implementation, when the power consumption of the external load is large and the board vibration frequency is no longer within the range that can be heard by the human ear, the controllable switch can be disconnected to reduce power consumption and extend the battery life of the electronic device.

[0009] In a possible implementation, the screen of the electronic device supports at least a first refresh rate and a second refresh rate, the first refresh rate is greater than the second refresh rate; the controllable switch is disconnected when the screen adopts the first refresh rate, and is turned on when the screen adopts the second refresh rate. In this implementation, when the screen of the electronic device adopts the lower second refresh rate, the load current required by the LCD panel is small. At this time, by connecting the load branch, the load current of the first output port of the bias power supply integrated circuit is increased, thereby increasing the load regulation frequency of the charge pump circuit, which can avoid the load regulation frequency being within the frequency range audible to the human ear, so that the plate vibration frequency is also not within the range audible to the human ear.

[0010] In a possible implementation, the electronic device further includes a controller, and the controller is used to control the controllable switch to be disconnected when the screen adopts a first refresh rate, and to control the controllable switch to be connected when the screen adopts a second refresh rate.

[0011] In a possible implementation, the first output port of the bias power integrated circuit is also used to power a touch panel of the electronic device. The touch panel is used to detect whether an object is close to the screen when the user is using the electronic device to make a call, so that the screen is turned off when an object is close and turned on when no object is close. The controllable switch is turned on when the screen is turned off and turned off when the screen is turned on.

[0012] In this implementation, the touch panel has low power consumption when realizing the object approach detection function, and the required load current is small. At this time, by connecting the load branch, the load current of the first output port of the bias power supply integrated circuit is increased, thereby increasing the load regulation frequency of the charge pump circuit, which can avoid the load regulation frequency being within the frequency range of 20Hz~20kHz, so that the board vibration frequency is also not within the range audible to the human ear.

[0013] In a possible implementation, the electronic device further includes a controller, and the controller is used to control the controllable switch to be turned on when the screen is off, and to control the controllable switch to be closed when the screen is on.

[0014] In a possible implementation, the bias power supply integrated circuit includes a boost circuit and a charge pump circuit. The boost circuit is used to boost the input voltage and output it to the charge pump circuit; the output end of the charge pump circuit is connected to the first output port of the bias power supply integrated circuit; the charge pump circuit is used to convert the voltage output by the boost circuit into a negative bias voltage; the load branch is used to make the load regulation frequency of the charge pump circuit greater than the first preset frequency when the load branch is connected; wherein the first preset frequency is greater than or equal to 20kHz, and the load regulation frequency is the frequency at which the charge pump circuit regulates the voltage of the power supply capacitor.

[0015] In a second aspect, the present application also provides a board oscillation regulating circuit, wherein the first end of the board oscillation regulating circuit is connected to the first output port of the bias power supply integrated circuit, the bias power supply integrated circuit is used to provide a negative bias voltage for the LCD panel of the liquid crystal display LCD, and the first output port of the bias power supply integrated circuit is used to output the negative bias voltage. The board oscillation regulating circuit includes a load branch, wherein the first end of the load branch is connected to the first output port of the bias power supply integrated circuit, and the second end of the load branch is grounded. The load branch is used to increase the load current output by the first output port of the bias power supply integrated circuit to adjust the board oscillation frequency of the power supply capacitor, the first end of the power supply capacitor is connected to the first output port of the bias power supply integrated circuit, and the second end of the power supply capacitor is grounded.

[0016] When the bias power supply integrated circuit is used in conjunction with the board vibration adjustment circuit, the load adjustment frequency of the bias power supply integrated circuit is not within the frequency range audible to the human ear, and thus the board vibration frequency of the power supply capacitor is also not within the frequency range audible to the human ear, thereby preventing users from hearing the board vibration sound and improving the user experience.

[0017] In a possible implementation, the load branch includes a resistor, a first end of the resistor is connected to a first end of the load branch, and a second end of the resistor is connected to a second end of the load branch.

[0018] In a possible implementation, the load branch includes: a resistor and a controllable switch. A first end of the controllable switch is connected to a first end of the load branch, a second end of the controllable switch is connected to a first end of the resistor, and a second end of the resistor is connected to a second end of the load branch.

[0019] In a possible implementation, the bias power supply integrated circuit at least includes a charge pump circuit, the output end of the charge pump circuit is connected to the first output port of the bias power supply integrated circuit, the output end of the charge pump circuit generates and outputs a negative bias voltage, and the absolute value of the negative bias voltage output by the charge pump circuit is a first voltage value; when the load regulation frequency of the charge pump circuit is a first preset frequency, the current output by the first output port of the bias power supply integrated circuit is a first current value, the minimum load current required by the subsequent load connected to the first output port is a second current value, and the difference between the first current value and the second current value is a first difference; the resistance value of the resistor is greater than the ratio of the first voltage value to the first difference; wherein the first preset frequency is greater than or equal to 20kHz, and the load regulation frequency is the frequency at which the charge pump circuit regulates the voltage of the power supply capacitor. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A circuit diagram of an electronic device including a bias power supply integrated circuit provided for the present application;

[0021] Figure 2 A circuit diagram of an electronic device provided in an embodiment of the present application;

[0022] Figure 3 A circuit diagram of another electronic device provided in an embodiment of the present application;

[0023] Figure 4 A voltage waveform diagram of VSN provided in an embodiment of the present application;

[0024] Figure 5 A circuit diagram of another electronic device provided in an embodiment of the present application;

[0025] Figure 6 A circuit diagram of another electronic device provided in an embodiment of the present application;

[0026] Figure 7 A schematic diagram of a plate vibration adjustment circuit provided in an embodiment of the present application. DETAILED DESCRIPTION

[0027] In order to enable persons skilled in the art to more clearly understand the solution of the present application, the application scenario of the technical solution of the present application is first described below.

[0028] See also Figure 1 , which is a circuit diagram of an electronic device including a bias power supply integrated circuit provided by the present application.

[0029] Currently, LCDs of electronic devices use a bias power integrated circuit 10 to provide positive and negative bias voltages required by LCD panels. The bias power integrated circuit 10 includes a boost circuit 11, a linear regulator (Low Dropout Regulator, LDO) power supply circuit 12, and a charge pump circuit 13.

[0030] The boost circuit 11 is used to boost the system voltage VIN of the electronic device. The linear regulator power supply circuit 12 is used to generate a stable positive bias voltage VSP using the voltage output by the boost circuit 11. The charge pump circuit 13 is used to convert the voltage output by the boost circuit 11 into a negative voltage, that is, to generate a negative bias voltage VSN.

[0031] For the charge pump circuit 13, the capacitor of the charge pump circuit 13 can be controlled by an internal feedback circuit (also called a feedback circuit) to send energy to the VSN port, so that the voltage of the VSN port can be continuously stabilized at the target voltage value. In addition, in order to stabilize the output voltage of the VSN port, an output capacitor C is set at the VSN port. VSN .

[0032] In the prior art, the piezoelectric effect may cause plate vibration when the power supply capacitor is working. When the frequency range of the plate vibration is within the frequency range of sound audible to the human ear, the user may hear the plate vibration sound.

[0033] In order to solve the above technical problems, the present application provides an electronic device and a board vibration adjustment circuit, which can change the frequency of the board vibration to prevent the user from hearing the board vibration sound, thereby improving the user experience and ensuring the call quality. The solution is simple to implement and the hardware cost is low.

[0034] The terms "first", "second", etc. in the description of this application are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features.

[0035] In the present application, unless otherwise clearly specified and limited, the term "connection" should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium.

[0036] See also Figure 2, which is a circuit diagram of an electronic device provided in an embodiment of the present application.

[0037] The embodiments of the present application do not specifically limit the type of electronic device. The electronic device may be a non-folding screen mobile phone, a folding screen mobile phone, a laptop computer, a wearable electronic device (such as a smart watch), a tablet computer, an augmented reality (AR) device, a virtual reality (VR) device, and a vehicle-mounted device, etc.

[0038] The electronic device shown in the figure includes: a bias power supply integrated circuit 10, a power supply capacitor C VSN , power supply capacitor C VSP and load branch 20.

[0039] The screen of the electronic device is a liquid crystal display (LCD), and the LCD uses a bias power integrated circuit 10 to provide a bias voltage. Specifically, the first output port of the bias power integrated circuit 10 is used to output a negative bias voltage, which is represented by VSN.

[0040] Power supply capacitor C VSN The first end of the bias power integrated circuit 10 is connected to the first output port of the bias power integrated circuit 10, and the power supply capacitor C VSN The second end is grounded.

[0041] In addition, the second output port of the bias power integrated circuit 10 is used to output a positive bias voltage, denoted by VSP. VSP The first end of the bias power supply integrated circuit 10 is connected to the second output port of the bias power supply integrated circuit 10, and the power supply capacitor C VSP The second end is grounded.

[0042] A first end of the load branch 20 is connected to the first output port of the bias power integrated circuit 10, and a second end of the load branch 20 is grounded. The load branch 20 is used to increase the load current output by the first output port of the bias power integrated circuit.

[0043] In order to enable those skilled in the art to more fully understand the working principle of the load branch 20, the specific reasons why the plate vibration frequency in the prior art is within the frequency range of sound audible to the human ear are first analyzed below.

[0044] See also Figure 3 , which is a circuit diagram of another electronic device provided in an embodiment of the present application.

[0045] Figure 3The bias power supply integrated circuit 10 in the embodiment includes a boost circuit 11, a linear regulator power supply circuit 12, and a charge pump circuit 13. The boost circuit 11 is used to boost the system voltage VIN of the electronic device. The linear regulator power supply circuit 12 is used to generate a stable positive bias voltage VSP using the voltage output by the boost circuit 11. The specific working principles of the boost circuit 11 and the linear regulator power supply circuit 12 are prior art and will not be described in detail herein.

[0046] When the charge pump circuit 13 switches between the following two working states:

[0047] State 1: When PMOS1 and NMOS2 are turned on and NMOS1 and NMOS3 are turned off, VIN is boosted by the Boost circuit 11 and becomes the capacitor C fly Charge;

[0048] State 2: When PMOS1 and NMOS2 of the charge pump circuit 13 are turned off, and NMOS1 and NMOS3 are turned on, C fly is the capacitance C VSN Charging, making C VSN Capable of providing a negative bias voltage VSN.

[0049] The feedback circuit inside the charge pump circuit 13 is not shown in the figure. The load regulation frequency of the feedback circuit inside the charge pump circuit 13 is the charge pump circuit 13 controlling the internal capacitor C VSN The frequency of charging is C VSN Due to the piezoelectric effect, the material will produce expansion and contraction deformation during operation, which will drive the circuit board or surrounding devices to vibrate and generate plate vibration. The frequency of the plate vibration can be considered as C VSN The maximum value of the load regulation frequency of the charge pump circuit 13 can generally reach 1 MHz, and the specific value of the load regulation frequency is related to the load size.

[0050] See also Figure 4 , which is a voltage waveform diagram of VSN provided in an embodiment of the present application.

[0051] The voltage value of VSN is also C VSN The voltage value, C fly is the capacitance C VSN When charging, due to C VSN The output is a negative voltage, C VSN The voltage of C VSN The absolute value of the voltage gradually increases. When it reaches the target voltage V1, C fly End with capacitor C VSN Charging, for example, at time T1 C VSNThe voltage of VSN reaches V1, and the charge pump circuit 13 ends the state 2. The voltage value of VSN begins to gradually decrease due to the load power consumption. When it drops below the reference voltage V2, the charge pump circuit 13 works in the state 1 again, C fly Again, the capacitor C VSN Charging, making C VSN The voltage returns to the target voltage V1 again. The time difference between T2 and T1 is C VSN The time of a single discharge, the time difference between T3 and T2 C fly is the capacitance C VSN Charging time.

[0052] C fly is the capacitance C VSN Charging depends on the following two conditions:

[0053] 1. The voltage value of VSN is insufficient, that is, C VSN Insufficient electricity on the

[0054] 2. The rising edge of the clock signal (CLK) of the load regulation frequency of the charge pump circuit 13 is detected.

[0055] The rising edge of the load regulation frequency is used to indicate C fly is the capacitance C VSN Time to charge.

[0056] Said Figure 4 The time difference between T2 and T1 is determined by C VSN The size of the load current and the load regulation frequency are determined by the load current. VSN The size and load current determine the rate at which the voltage drops. Figure 4 The load regulation frequency determines the minimum value of the voltage drop.

[0057] The load regulation frequency will decrease as the load current of the VSN port decreases. Because the load current is small, C VSN Energy consumption is slow, so high frequency fast C is not required VSN Reducing the load regulation frequency can reduce the heat and power consumption of the circuit.

[0058] However, when the load current of the VSN port is small, the load regulation frequency of VSN may just drop to the frequency range of 20Hz~20kHz, which is the frequency range of sound that can be heard by the human ear. That is, the frequency range of the board vibration is just within the frequency range of sound that can be heard by the human ear. At this time, if the user approaches the electronic device, the board vibration sound can be heard.

[0059] Continue to see Figure 3The solution of the embodiment of the present application adds a load branch 20 at the VSN port. The load branch 20 is equivalent to an electrical device and needs to consume electrical energy. Therefore, a load current will flow through the load branch 20, so that the load current of the first output port of the bias power supply integrated circuit 10 is not only the load current of the external load 30 originally connected to the VSN port, but also the load current in the load branch 20 is superimposed, which is equivalent to increasing the load current of the first output port of the bias power supply integrated circuit 10.

[0060] Since the load current of the first output port of the bias power supply integrated circuit 10 is increased, the load regulation frequency of the charge pump circuit 13 is increased. By reasonably selecting the load current size of the load branch, the load regulation frequency can be avoided to be in the frequency range of 20Hz~20kHz. For example, even if the load current of the external load is zero, the load regulation frequency can still be greater than or equal to 20kHz.

[0061] To sum up, the electronic device provided in the embodiment of the present application can set a load branch so that the load regulation frequency of the bias power supply integrated circuit is not within the frequency range audible to the human ear, and thus the board vibration frequency of the power supply capacitor is also not within the frequency range audible to the human ear, thereby preventing the user from hearing the board vibration sound, improving the user experience, and ensuring call quality.

[0062] The implementation method of the load branch is described in detail below.

[0063] See also Figure 5 , which is a circuit diagram of another electronic device provided in an embodiment of the present application.

[0064] Figure 5 In the electronic device shown, the load branch 20 includes a resistor R. A first end of the resistor R is connected to a first end of the load branch 20 , and a second end of the resistor R is connected to a second end of the load branch 20 .

[0065] The resistor R is equivalent to a load device. When connected to the circuit, a load current is generated on the branch where the resistor R is located, which increases the load current of the first output port of the bias power supply integrated circuit 10, thereby increasing the load regulation frequency of the charge pump circuit 13, and can avoid the load regulation frequency being in the frequency range of 20Hz~20kHz. For example, even if the load current of the external load is zero, the plate vibration frequency of the power supply capacitor is not in the frequency range audible to the human ear. It should be noted that the embodiment of the present application does not limit the specific value of the resistor R. In actual applications, the specific value of the resistor R is related to the parameters of the charge pump circuit and the size of the load current required by the external load 30. The value of the resistor R on different electronic devices may be different, so it can be calibrated for different electronic devices. The specific method of calibrating the value of the resistor R is introduced below.

[0066] The absolute value of the negative bias voltage output by the charge pump circuit 13 is a first voltage value.

[0067] When the load branch is not connected to the first output port of the bias power integrated circuit 10, the load of the first output port is adjusted so that the load regulation frequency of the charge pump circuit is the first preset frequency. The first preset frequency is greater than or equal to 20kHz to ensure that the plate vibration frequency is not within the frequency range audible to the human ear. In practical applications, the first preset frequency can be set to a boundary condition of 20kHz, and at this time, the load current output by the first output port of the bias power integrated circuit 10 is determined to be the first current value.

[0068] The minimum load current required by the external load 30 of the electronic device is the second current value. The minimum load current required by the external load 30 can be determined according to the actual situation of the external load 30, and is not specifically limited in the embodiment of the present application.

[0069] The difference between the first current value and the second current value is determined as the first difference. The first difference represents the magnitude of the current that should flow through the load branch. Then the value of the resistor R in the load branch is greater than the ratio of the first voltage value to the first difference, so as to ensure that the plate vibration frequency is not within the frequency range that can be heard by the human ear.

[0070] In summary, the load branch provided in the embodiment of the present application only includes a resistor device. By reasonably selecting the resistance value of the resistor device, the load adjustment frequency of the bias power supply integrated circuit can be made not within the frequency range audible to the human ear, so that the plate vibration frequency of the power supply capacitor is also not within the frequency range audible to the human ear, thereby preventing the user from hearing the plate vibration sound, improving the user experience, and ensuring the call quality. In addition, the implementation method has a simple circuit structure and low hardware cost.

[0071] Another implementation method of the load branch is described in detail below.

[0072] See also Figure 6 , which is a circuit diagram of another electronic device provided in an embodiment of the present application.

[0073] Figure 6 In the electronic device shown, the load branch 20 includes a resistor R and a controllable switch Q.

[0074] A first end of the controllable switch Q is connected to a first end of the load branch 20 , a second end of the controllable switch Q is connected to a first end of the resistor R, and a second end of the resistor R is connected to a second end of the load branch 20 .

[0075] The controllable switch Q can be an insulated gate bipolar transistor (IGBT), a metal oxide semiconductor field effect transistor (MOSFET, hereinafter referred to as MOS tube), a silicon carbide metal oxide semiconductor (SiC MOSFET), etc. In the embodiment of the present application, the controllable switch Q is specifically an NMOS tube for explanation.

[0076] At this time, the first end of the controllable switch Q is the drain, and the second end is the source.

[0077] In the solution of the embodiment of the present application, the controllable switch Q can be controlled by the controller of the electronic device. When the power consumption of the external load 30 connected to the VSN port is large, the load current output by the first output port of the bias power supply integrated circuit 10 is large. At this time, the load regulation frequency of the charge pump circuit 13 is large and is not within the frequency range that can be heard by the human ear. At this time, the user cannot hear the output capacitor C VSN There is no need to connect R to increase the load current at this time, so the controller can control the controllable switch to disconnect. At this time, R is not connected to the circuit, so R does not consume power, and the power consumption of the external load 30 is large, saving power consumption.

[0078] When the power consumption of the external load 30 connected to the VSN port is small, the load current output by the first output port of the bias power supply integrated circuit 10 is small. At this time, the load regulation frequency of the charge pump circuit 13 is small and is within the frequency range audible to the human ear. In order to prevent the user from hearing the output capacitor C VSN The board vibration sound, at this time, you need to connect R to increase the load current, and then C VSN The plate vibration frequency moves out of the frequency range that can be heard by the human ear. At this time, the controller can control the controllable switch to close, and R is connected to the circuit.

[0079] It should be noted that the embodiment of the present application does not limit the specific value of the resistor R. In actual applications, the specific value of the resistor R is related to the parameters of the charge pump circuit and the load current required by the external load 30. The value of the resistor R may be different on different electronic devices. Therefore, it can be calibrated for different electronic devices separately. The specific method of calibrating the value of the resistor R is introduced below.

[0080] The absolute value of the negative bias voltage output by the charge pump circuit 13 is a first voltage value.

[0081] When the load branch is not connected to the first output port of the bias power integrated circuit 10, the load of the first output port is adjusted so that the load regulation frequency of the charge pump circuit is the first preset frequency. The first preset frequency is greater than or equal to 20kHz to ensure that the plate vibration frequency is not within the frequency range audible to the human ear. In practical applications, the first preset frequency can be set to a boundary condition of 20kHz, and at this time, the load current output by the first output port of the bias power integrated circuit 10 is determined to be the first current value.

[0082] The minimum load current required by the external load 30 of the electronic device is the second current value. The minimum load current required by the external load 30 can be determined according to the actual situation of the external load 30, and is not specifically limited in the embodiment of the present application.

[0083] The difference between the first current value and the second current value is determined as the first difference. The first difference represents the magnitude of the current that should flow through the load branch. If the impedance of the controllable switch Q in the load branch 20 is negligible, the value of the resistance R in the load branch 20 is greater than the ratio of the first voltage value to the first difference, so as to ensure that the plate vibration frequency is not within the frequency range that can be heard by the human ear.

[0084] In summary, the load branch provided in the embodiment of the present application only includes a resistor device and a controllable switch. By reasonably selecting the resistance value of the resistor device, the load adjustment frequency of the bias power supply integrated circuit can be made not within the frequency range audible to the human ear, so that the plate vibration frequency of the power supply capacitor is also not within the frequency range audible to the human ear, thereby preventing the user from hearing the plate vibration sound, improving the user experience, and ensuring the call quality. In addition, the implementation method has a simple circuit structure and low hardware cost. When the power consumption of the external load is large, the controllable switch can also be actively controlled to be disconnected to reduce power consumption and extend the battery life of the electronic device.

[0085] The application scenarios of this application solution are described in detail below.

[0086] In one possible application scenario, the screen of an electronic device can support multiple refresh rates, for example, supporting at least two of different refresh rates such as 144Hz, 120Hz, 90Hz, and 60Hz. The screen refresh rate refers to the number of images displayed on the screen in one second. Generally speaking, the higher the refresh rate, the smoother the image display and the better the user experience, but the corresponding load power consumption and load current are greater.

[0087] When the screen of the electronic device adopts a high refresh rate, the load current output by the first output port of the bias power integrated circuit 10 for powering the LCD panel is relatively large. At this time, the load regulation frequency of the charge pump circuit 13 is relatively large and is not within the frequency range audible to the human ear. At this time, the user cannot hear the output capacitor C VSNHowever, when the user switches the high refresh rate to a low refresh rate, the load of the VSN port will change, as described below.

[0088] Each frame can be decomposed into pixels, each pixel has independent color information, and these pixels are scanned in rows and columns on the screen to form a frame. Horizontal blanking refers to the time when a row of pixels is scanned from left to right. Before scanning the next row, it is necessary to return to the left and prepare to scan the next row of pixels. The time between these is called horizontal blanking. Vertical blanking refers to the time when the screen returns to the upper left corner of the screen to prepare to scan the next frame after scanning all the rows of pixels. The time is called vertical blanking. The line synchronization signal (HSYNC) is used to indicate the start of scanning a new row of pixels, and the field synchronization signal (VSYNC) is used to indicate that a new picture is to be displayed. When the line synchronization signal or the field synchronization signal is sent, the video data must be enabled immediately, and preparation time needs to be reserved. Taking row scanning as an example, the time from the end of the row synchronization signal to the start of the data enable signal is called the back porch of the row scanning, and the time from the end of the data enable signal to the start of the row synchronization signal is called the front porch of the row scanning. Similarly, for column scanning, the back porch of column scanning and the front porch of column scanning can also be defined. The back porch and the front porch are collectively called porch.

[0089] When the screen switches from a high refresh rate to a low refresh rate, the electronic device reduces the refresh rate by increasing the Porch. For example, when switching from 120Hz to 60Hz, a frame of normal display is adjacent to a frame of the Porch area. The time of a frame of the Porch area is the scanning preparation time, and no display is performed, thereby achieving a reduction in the refresh rate. However, since the Porch area is a non-display area, the power consumption is low, and the load current required by the LCD panel is small. Therefore, the load adjustment frequency of the charge pump circuit 13 in the Porch area is small, so that the user can hear the output capacitor C VSN The plate vibration sound.

[0090] Through actual simulation tests, when the LCD screen of the electronic device adopts a refresh rate of 60Hz, when in the Porch region, the minimum value of the load regulation frequency of the charge pump circuit 13 is 3.4kHz, which is within the frequency range of 20Hz~20kHz. At this time, by setting a load branch on the electronic device, the load current of the first output port of the bias power supply integrated circuit 10 is increased, thereby increasing the load regulation frequency of the charge pump circuit 13, which can avoid the load regulation frequency being within the frequency range of 20Hz~20kHz.

[0091] Furthermore, for Figure 6In the implementation shown, the load branch 20 includes a controllable switch Q and a resistor R connected in series. When the screen of the electronic device adopts a higher first refresh rate, the processor of the electronic device can control the controllable switch to be disconnected, so that the resistor R is disconnected from the first output port of the bias power integrated circuit 10 to reduce power consumption; when the screen of the electronic device adopts a lower second refresh rate, the processor controls the controllable switch to be closed, so that the resistor R is connected to the first output port of the bias power integrated circuit 10, increasing the load current and the load regulation frequency of the charge pump circuit 13, so that the user cannot hear the C VSN The plate vibration sound.

[0092] The processor of the electronic device may include one or more processing units, for example: the processor may include an application processor (AP), a modem processor, a graphics processor (GPU), an image signal processor (ISP), a controller, a video codec, a digital signal processor (DSP), a baseband processor, and / or a neural-network processing unit (NPU), etc. Among them, different processing units can be independent devices or integrated in one or more processors. The controller can generate an operation control signal according to the instruction opcode and the timing signal to complete the control of fetching and executing instructions. The control of the controllable switch Q can be implemented by the controller.

[0093] In this scenario, the method for determining the resistance value of the resistor in the load branch is similar to the above description, but it should be noted that since the second current value is the minimum load current required by the subsequent load, when the subsequent load is an LCD panel operating at a low refresh rate, its minimum load current also needs to be calibrated. For example, according to experience, when the LCD screen displays a fixed black screen, the power consumption is the lowest, and the load current at this time can be determined as the second current value. It can be understood that the above is only for example illustration and does not constitute a limitation on the calibration method of the second current value. In actual applications, the second current value can also be determined by multiple experiments, simulation tests, and other methods.

[0094] Normally, when the screen of an electronic device is off, since no picture is displayed, the VSN port does not need to provide a negative bias voltage to the LCD panel. At this time, the output capacitor C VSNNo charging is required, and the user will not hear the vibration sound. However, in some electronic devices, the touch panel (TP) also has the function of a proximity light sensor. Specifically, the TP can determine whether there is an object approaching the screen of the electronic device. When it is determined that there is an object approaching the screen, it will automatically turn off the screen to save power. A typical application scenario is that the user holds the electronic device close to the ear to make a call. At this time, when the TP is on a call, when it detects that there is an object approaching the screen, it will trigger the electronic device to turn off the screen. After the screen is turned off, if it detects that there is no object approaching the screen, it will trigger the electronic device to light up the screen.

[0095] When TP implements the object proximity detection function, it is powered by the VSN port. When the user approaches the screen during a call and TP triggers the electronic device to turn off the screen, although the VSN port does not need to provide a negative bias voltage to the LCD panel, it still needs to continuously power the TP so that the TP can detect in real time whether the object is far away from the screen so as to trigger the electronic device to light up the screen in time.

[0096] In this process, the external load of the VSN port is equivalent to only TP, but the power consumption of TP is low when realizing the object proximity detection function, and the required load current is small, so that the load regulation frequency of the charge pump circuit 13 is small, and the output capacitor C VSN The board vibration sound falls within the frequency range of 20Hz~20kHz, and at this time the user is on a call, the distance between the ear and the screen is close, and the probability of hearing the board vibration sound is greatly increased.

[0097] At this time, by setting the load branch 20 on the electronic device, the load current of the first output port of the bias power supply integrated circuit 10 is increased, thereby increasing the load regulation frequency of the charge pump circuit 13, and avoiding the load regulation frequency being within the frequency range of 20Hz~20kHz.

[0098] Furthermore, for Figure 6 In the implementation shown, the load branch 20 includes a controllable switch Q and a resistor R connected in series. When the screen is off, the processor of the electronic device can control the controllable switch Q to close, so that the resistor R is connected to the first output port of the bias power integrated circuit 10, increase the load current, and increase the load regulation frequency of the charge pump circuit 13, so that the user cannot hear the C VSN when the screen of the electronic device is turned on, the processor can control the controllable switch Q to disconnect so that the resistor R is disconnected from the first output port of the bias power supply integrated circuit 10 to reduce power consumption.

[0099] It is understandable that the above two scenarios can also be integrated, for example, the electronic device supports different refresh rates and the TP has the function of a proximity light sensor. At this time, when the screen of the electronic device is lit and the electronic device uses a higher refresh rate, the processor controls the controllable switch Q to be disconnected to reduce power consumption; when the screen of the electronic device is lit and the electronic device uses a lower refresh rate, the controllable switch Q is controlled to continue to remain closed to increase the load current and load regulation frequency, and avoid the load regulation frequency being in the frequency range of 20Hz~20kHz.

[0100] In this scenario, the method of determining the resistance value of the resistor in the load branch is similar to the above description, but it should be noted that since the second current value is the minimum load current required by the subsequent load, when the subsequent load is TP, its minimum load current also needs to be calibrated. For example, according to experience, the minimum load current is the current value when the electronic device is off and TP continues to detect the presence of an object close to the screen of the electronic device. It can be understood that the above is only an example and does not constitute a limitation on the calibration method of the second current value. In actual applications, the second current value can also be determined by multiple experiments, simulation tests, and other methods.

[0101] Based on the electronic device provided in the above embodiments, the embodiment of the present application further provides a board vibration adjustment circuit, which is described in detail below with reference to the accompanying drawings.

[0102] See also Figure 7 , which is a schematic diagram of a plate vibration adjustment circuit provided in an embodiment of the present application.

[0103] The board vibration regulating circuit 200 comprises a load branch 20, wherein a first terminal PIN1 of the load branch 20 is used to connect to a power source, for example, a negative bias voltage output port of a bias power integrated circuit, and a second terminal PIN2 of the load branch 20 is used to be grounded.

[0104] The board oscillation regulating circuit 200 is used to increase the load current outputted from the negative bias voltage output port of the bias power integrated circuit to adjust the board oscillation frequency of the power supply capacitor. The first end of the power supply capacitor is connected to the first output port of the bias power integrated circuit, and the second end of the power supply capacitor is grounded. That is, the board oscillation regulating circuit 200 is connected in parallel with the power supply capacitor at the negative bias voltage output port of the bias power integrated circuit.

[0105] The specific principle of the load branch 20 to achieve plate vibration frequency regulation can be found in the relevant descriptions in the above embodiments, which will not be repeated here.

[0106] In a possible implementation, the board oscillation regulating circuit 200 exists in the form of a peripheral circuit of a bias power supply integrated circuit.

[0107] In another possible implementation, the board oscillation regulating circuit 200 may also be integrated into a bias power supply integrated circuit.

[0108] See also Figure 5 The load branch 20 of the board vibration regulating circuit 200 may include a resistor R, a first end of the resistor R is connected to a first end of the load branch 20, and a second end of the resistor R is connected to a second end of the load branch.

[0109] In this implementation, the board vibration regulating circuit 200 has a simple circuit structure, low hardware cost, and does not require active control. It can operate completely passively and has high reliability.

[0110] See also Figure 6 The load branch 20 of the board vibration regulation circuit 200 may also include a resistor R and a controllable switch Q, wherein the first end of the controllable switch Q is connected to the first end of the load branch 20, the second end of the controllable switch Q is connected to the first end of the resistor R, and the second end of the resistor R is connected to the second end of the load branch 20.

[0111] In a possible implementation, the resistance value of resistor R can be calibrated according to the operation conditions of the bias power integrated circuit and the electronic device. The absolute value of the negative bias voltage output by the charge pump circuit of the bias power integrated circuit is a first voltage value. When the load regulation frequency of the charge pump circuit is a first preset frequency, the current output by the first output port of the bias power integrated circuit is a first current value, the minimum load current required by the subsequent load connected to the first output port is a second current value, and the difference between the first current value and the second current value is a first difference. The resistance value of resistor R is greater than the ratio of the first voltage value to the first difference. Wherein, the first preset frequency is greater than or equal to 20kHz to ensure that the plate vibration frequency is not in the frequency range audible to the human ear.

[0112] To sum up, when the bias power supply integrated circuit is used in conjunction with the board vibration adjustment circuit, the load adjustment frequency of the bias power supply integrated circuit is not within the frequency range audible to the human ear, and thus the board vibration frequency of the power supply capacitor is also not within the frequency range audible to the human ear, thereby preventing users from hearing the board vibration sound and improving the user experience.

[0113] It is understandable that the board vibration adjustment circuit provided in the embodiment of the present application can also be used to adjust the board vibration of other electronic devices, such as tablet computers, smart wearable devices, etc., and the embodiment of the present application does not make specific limitations. In addition, the board vibration adjustment circuit can also change the board vibration frequency adjustment capability of the power supply capacitor according to needs, such as adjusting the board vibration frequency of the power supply capacitor to other specific frequency ranges, such as adjusting the board vibration frequency to a frequency range above 30kHz.

[0114] As described above, the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. An electronic device, characterized in that: The screen of the electronic device is a liquid crystal display screen, and the electronic device comprises: a bias power supply integrated circuit, a load branch, and a power supply capacitor; The bias power integrated circuit is used to provide a negative bias voltage for the liquid crystal display panel of the screen, and the first output port of the bias power integrated circuit is used to output the negative bias voltage; A first end of the power supply capacitor is connected to a first output port of the bias power supply integrated circuit, and a second end of the power supply capacitor is grounded; The first end of the load branch is connected to the first output port of the bias power integrated circuit, and the second end of the load branch is grounded; The load branch includes: a resistor and a controllable switch; The first end of the controllable switch is connected to the first end of the load branch, the second end of the controllable switch is connected to the first end of the resistor, and the second end of the resistor is connected to the second end of the load branch; The controllable switch is used to be disconnected when the screen of the electronic device adopts a first refresh rate, and to be turned on when the screen adopts a second refresh rate, and the first refresh rate is greater than the second refresh rate; and / or, when the first output port of the bias power integrated circuit is also used to power a touch panel of the electronic device, the controllable switch is turned on when the screen is off, and is disconnected when the screen is on, wherein the touch panel is used to detect whether there is an object approaching the screen during a user using the electronic device to make a call, so that the screen is turned off when an object is approaching, and is turned on when no object is approaching; The load branch is used to increase the load current output by the first output port of the bias power integrated circuit.

2. The electronic device according to claim 1, characterized in that: The electronic device further comprises a controller; The controller is used to control the controllable switch to be turned off when the screen adopts the first refresh rate, and to control the controllable switch to be turned on when the screen adopts the second refresh rate.

3. The electronic device according to claim 1, characterized in that: The electronic device further comprises a controller; The controller is used to control the controllable switch to be turned on when the screen is off, and to control the controllable switch to be closed when the screen is on.

4. The electronic device according to any one of claims 1 to 3, characterized in that: The bias power integrated circuit includes a boost circuit and a charge pump circuit; The boost circuit is used to boost the input voltage and output it to the charge pump circuit; The output end of the charge pump circuit is connected to the first output port of the bias power integrated circuit; The charge pump circuit is used to convert the voltage output by the boost circuit into the negative bias voltage; The load branch is used to make the load regulation frequency of the charge pump circuit greater than a first preset frequency when the load branch is connected; The first preset frequency is greater than or equal to 20 kHz, and the load regulation frequency is the frequency at which the charge pump circuit regulates the voltage of the power supply capacitor.

5. A plate vibration regulating circuit, characterized in that: The first end of the plate vibration regulating circuit is connected to the first output port of the bias power integrated circuit, the bias power integrated circuit is used to provide a negative bias voltage for the liquid crystal display panel of the liquid crystal display, and the first output port of the bias power integrated circuit is used to output the negative bias voltage; The plate vibration regulating circuit comprises a load branch, a first end of the load branch is connected to a first output port of the bias power supply integrated circuit, and a second end of the load branch is grounded; The load branch is used to increase the load current output by the first output port of the bias power integrated circuit to adjust the plate oscillation frequency of the power supply capacitor, wherein the first end of the power supply capacitor is connected to the first output port of the bias power integrated circuit, and the second end of the power supply capacitor is grounded; The load branch includes: a resistor and a controllable switch; The first end of the controllable switch is connected to the first end of the load branch, the second end of the controllable switch is connected to the first end of the resistor, and the second end of the resistor is connected to the second end of the load branch; The controllable switch is used to be disconnected when the screen of the electronic device adopts a first refresh rate, and to be turned on when the screen adopts a second refresh rate, and the first refresh rate is greater than the second refresh rate; and / or, when the first output port of the bias power supply integrated circuit is also used to power the touch panel of the electronic device, the controllable switch is turned on when the screen is off, and disconnected when the screen is on, wherein the touch panel is used to detect whether there is an object approaching the screen when the user is using the electronic device to make a call, so that the screen is turned off when an object is approaching, and is lit when no object is approaching.

6. The plate vibration regulating circuit according to claim 5, characterized in that: The bias power supply integrated circuit at least includes a charge pump circuit, the output end of the charge pump circuit is connected to the first output port of the bias power supply integrated circuit, the output end of the charge pump circuit generates and outputs the negative bias voltage, and the absolute value of the negative bias voltage output by the charge pump circuit is a first voltage value; When the load regulation frequency of the charge pump circuit is a first preset frequency, the current output by the first output port of the bias power supply integrated circuit is a first current value, the minimum load current required by the subsequent load connected to the first output port is a second current value, and the difference between the first current value and the second current value is a first difference; The resistance value of the resistor is greater than the ratio of the first voltage value to the first difference; The first preset frequency is greater than or equal to 20 kHz, and the load regulation frequency is the frequency at which the charge pump circuit regulates the voltage of the power supply capacitor.

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