Voltage regulator, chip and electronic equipment

Abstract

The invention discloses a voltage stabilizer, a chip and electronic equipment, and belongs to the technical field of electronic information. The voltage stabilizer comprises a first control circuit which is used for outputting a first signal to a first driving circuit when the voltage stabilizer works in a voltage difference region and outputting a second signal to the first driving circuit when the voltage stabilizer works in a linear region, and the driving capability of the first signal is higher than that of the second signal; the first driving circuit is used for converting the input voltage under the action of the first signal or the second signal and providing the converted voltage to the output end of the voltage stabilizer; under the condition that the voltage stabilizer works in the voltage difference area, the voltage difference between the converted voltage and the input voltage is smaller than a first threshold value. The stability of the output voltage in the voltage difference region can be enhanced, the voltage difference between the output voltage and the input voltage is reduced, and the stability and the reliability of the voltage stabilizer in the whole working region are improved.

Description

Technical Field

[0001] This application relates to the field of electronic information technology, and in particular to a voltage regulator, chip, and electronic device. Background Technology

[0002] A voltage regulator is a circuit that can output a stable voltage. It is often used to provide drive voltage to loads such as display drivers and power management circuits to drive the load.

[0003] Typically, a voltage regulator operates within three regions during power-up: the cutoff region, the differential voltage region, and the linear region. When the input voltage is less than a first voltage threshold, the regulator operates in the cutoff region, at which point the output voltage is not output and the regulator has no power supply capability. When the input voltage is greater than or equal to the first voltage threshold but less than a second voltage threshold, the regulator operates in the differential voltage region, and the output voltage increases with the input voltage. When the input voltage is greater than the second voltage threshold, the regulator operates in the linear region, and the output voltage value is relatively fixed.

[0004] In related technologies, when a voltage regulator operates in the differential voltage region, the output voltage is affected by the load connected to the regulator. For example, a heavy load can cause the output voltage to drop, which in turn makes the stability of the output voltage worse. Summary of the Invention

[0005] This application provides a voltage regulator, chip, and electronic device to solve problems in related technologies.

[0006] On the one hand, a voltage regulator is provided, the voltage regulator including a first control circuit and a first drive circuit; The first control circuit is configured to output a first signal to the first drive circuit when the voltage regulator is operating in the differential voltage region; and to output a second signal to the first drive circuit when the voltage regulator is operating in the linear region, wherein the driving capability of the first signal is higher than that of the second signal. The first driving circuit is used to convert the input voltage under the action of the first signal or the second signal, and provide the converted voltage to the output terminal of the voltage regulator; when the voltage regulator is operating in the differential voltage region, the voltage difference between the converted voltage and the input voltage is less than a first threshold.

[0007] In one possible implementation, the first driving circuit is configured to, under the action of the first signal, convert the input voltage into a first output voltage and provide the first output voltage to the output terminal of the regulator; and under the action of the second signal, convert the input voltage into a second output voltage and provide the second output voltage to the output terminal of the regulator, wherein the voltage difference between the second output voltage and the stable voltage of the regulator is less than the first threshold.

[0008] In one possible implementation, the voltage regulator further includes a second control circuit and a second drive circuit; The second control circuit is used to output a third signal to the second drive circuit when the voltage regulator is operating in the differential pressure region; The second driving circuit is used to convert the input voltage into a third output voltage under the action of the third signal, and provide the third output voltage to the output terminal of the regulator. The voltage difference between the sum of the third output voltage and the first output voltage and the input voltage is less than a second threshold, and the second threshold is less than the first threshold.

[0009] In one possible implementation, the second control circuit is further configured to output a fourth signal to the second drive circuit when the voltage regulator is operating in the linear region. The second driving circuit is also used to stop converting the input voltage into the third output voltage under the action of the fourth signal.

[0010] In one possible implementation, the first control circuit includes a negative feedback circuit, an error amplifier circuit, and a first selector, wherein a first input terminal of the first selector is connected to the output terminal of the error amplifier circuit, and a second input terminal of the first selector is connected to the signal terminal of the first signal. The negative feedback circuit is used to convert the voltage output from the output terminal of the voltage regulator into a feedback voltage according to a first ratio. The error amplifier circuit is used to compare the reference voltage with the feedback voltage, and output the second signal based on the voltage difference between the reference voltage and the feedback voltage; The first selector is used to select the first signal output when the voltage regulator is operating in the differential pressure region, and to select the second signal output when the voltage regulator is operating in the linear region.

[0011] In one possible implementation, the voltage regulator further includes a detection circuit; the detection circuit is configured to detect the operating range of the voltage regulator based on the input voltage, and when the voltage regulator is detected to be operating in the differential voltage region, send a first control signal to the first control circuit; and when the voltage regulator is detected to be operating in the linear region, send a second control signal to the first control circuit. The first control circuit is further configured to determine, upon receiving the first control signal, that the voltage regulator is operating in the differential pressure region; and upon receiving the second control signal, to determine that the voltage regulator is operating in the linear region.

[0012] In one possible implementation, the detection circuit includes an input conversion circuit and a comparison circuit; The input conversion circuit is used to convert the input voltage into a first voltage; The comparison circuit is used to compare the first voltage with the reference voltage, and determine whether the voltage regulator operates in the differential voltage region or the linear region based on the relationship between the first voltage and the reference voltage.

[0013] In one possible implementation, the input conversion circuit includes a resistor divider circuit and a low-pass filter; The resistor voltage divider circuit is used to convert the input voltage into a second voltage according to a second ratio; The low-pass filter is used to filter the second voltage to obtain the first voltage.

[0014] In one possible implementation, the detection circuit further includes a power-on reset circuit; The power-on reset circuit is used to send a reset signal to the comparator circuit when the input voltage is less than or equal to a first voltage threshold, and to send a reset cancellation signal to the comparator circuit when the input voltage is greater than the first voltage threshold. The comparison circuit is configured to enter a reset state upon receiving the reset signal, without comparing the first voltage with the reference voltage; and to exit the reset state upon receiving the reset cancellation signal, and then compare the first voltage with the reference voltage.

[0015] On the other hand, a chip is provided, the chip comprising: a load, and a voltage regulator as described in one aspect above; The voltage regulator is connected to the load and is used to provide an output voltage to the load so as to drive the load to work.

[0016] On the other hand, an electronic device is provided, the electronic device comprising the chip as described in the other aspect above.

[0017] The technical solution provided in this application can bring at least the following beneficial effects: In this voltage regulator, the first control circuit can control the driving capability of the output signal according to the operating range of the voltage regulator, thereby adjusting the voltage conversion mode of the first drive circuit. When the voltage regulator is working in the differential voltage range, the voltage difference between the output voltage converted by the first drive circuit and the input voltage is kept within a first threshold, avoiding the output voltage from decreasing due to load influence, and enhancing the stability and reliability of the output voltage in the differential voltage range. When the voltage regulator is working in the linear range, the voltage difference between the output voltage converted by the first drive circuit and the fixed stable voltage is kept within the first threshold. Thus, the stability and reliability of the voltage regulator are improved throughout the entire operating range. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the operating range of a low-dropout linear regulator provided in an embodiment of this application; Figure 2 This is a timing diagram of voltage changing over time provided in an embodiment of this application; Figure 3 This is a schematic diagram of the structure of a voltage regulator provided in an embodiment of this application; Figure 4 This is a schematic diagram of another voltage regulator provided in an embodiment of this application; Figure 5 This is a schematic diagram of another voltage regulator provided in an embodiment of this application; Figure 6 This is a schematic diagram of a detection circuit provided in an embodiment of this application; Figure 7 This is a schematic diagram of another voltage regulator provided in an embodiment of this application; Figure 8 This is a schematic diagram of another detection circuit provided in an embodiment of this application; Figure 9 This is a flowchart illustrating the operation of a voltage regulator provided in an embodiment of this application; Figure 10 This is a signal timing diagram of a voltage regulator under heavy load provided in an embodiment of this application. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0021] With the development of display electronics technology, higher requirements have been placed on the power supply network inside the display driver integrated circuit (DDIC), necessitating the addition of a low-dropout regulator (LDO) circuit to provide a stable power supply. An LDO is a commonly used power management module used to convert a higher input voltage into a stable, lower output voltage.

[0022] For example, an LDO circuit receives an input voltage Vin at its input terminal and outputs an output voltage Vddr at its output terminal. The core function of the LDO circuit is to stably convert the input voltage Vin into the output voltage Vddr. The output voltage Vddr is connected to a load circuit to provide a stable power output to the load circuit. The LDO circuit includes an error amplifier (EA), a power transistor PM, and resistors R1 and R2. The power transistor PM is a P-type MOSFET device, also known as a PMOS transistor. A PMOS transistor conducts when the gate voltage is low and is cut off when the gate voltage is high. Optionally, the power transistor PM can be replaced with an NMOS transistor or a bipolar junction transistor (BJT). An NMOS transistor, also known as an N-type MOSFET device, conducts when the gate voltage is high and is cut off when the gate voltage is low.

[0023] Resistors R1 and R2 form a voltage divider, used to divide the output voltage Vddr to obtain the feedback voltage (Voltage Feedback, Vfb). The voltage division ratio is R2 / (R1+R2), i.e., Vfb = R2 / (R1+R2) * Vddr. The feedback voltage Vfb is fed back to the positive input terminal (+) of EA, thus forming a negative feedback loop. The error amplifier EA compares the deviation between the feedback voltage Vfb and the reference voltage (Voltage Reference, Vref), outputting a deviation signal Vg. The deviation signal Vg is connected to the gate of the power transistor PM, used to control the conduction level of the power transistor PM. The source of the power transistor PM is connected to the input terminal of the input voltage, and the drain of the power transistor PM is connected to the output terminal of the output voltage. By controlling the conduction level of the power transistor PM, the output voltage Vddr is kept stable.

[0024] Exemplarily, the error amplifier EA compares the reference voltage Vref and the feedback voltage Vfb. If Vfb < Vref, it means that the output voltage Vddr is too low, then the deviation signal Vg output by EA decreases, making the conduction of the power transistor PM stronger, and thus the output voltage Vddr increases; if Vfb > Vref, it means that the output voltage Vddr is too high, then the deviation signal Vg output by EA increases, making the conduction of the power transistor PM weaker, and thus the output voltage Vddr decreases. Thereby, the output voltage Vddr closely follows the ratio of the reference voltage Vref. When the LDO reaches a stable output state, Vfb ≈ Vref, and Vddr ≈ Vfb * (R1 + R2) / R2.

[0025] Among them, during the power-on process of the LDO circuit, according to the range of the input voltage Vin, the working range of the LDO circuit includes three parts: the cut-off region, the voltage difference region, and the linear region. Exemplarily, as Figure 1 shown, when Vin < V1, the LDO circuit is in the cut-off region, and the output voltage Vddr has not started to output, that is, the voltage value of the output voltage Vddr remains 0 continuously. At this time, the LDO circuit has no power supply ability to the outside; when V1 ≤ Vin < V2, the LDO circuit is in the voltage difference region, and the output voltage Vddr changes with the input voltage Vin, that is, the voltage value of the output voltage Vddr starts to increase linearly; when V2 ≤ Vin, the LDO circuit is in the linear region, and the output voltage Vddr is stably output, that is, the voltage value of the output voltage Vddr is relatively fixed. At this time, the LDO circuit provides a stable power supply output to the load. In actual applications or tests, to ensure the working ability level of the DDIC under different external power supplies, it is required that the LDO circuit also has the ability to output a stable power supply in the voltage difference region.

[0026] However, when the LDO circuit is in the voltage difference region, since the power transistor PM is in the linear working range, that is, the power transistor PM is partially conductive, the equivalent resistance of the power transistor PM becomes larger and the driving ability is insufficient. Therefore, when the load of the LDO circuit changes, the output voltage Vddr changes violently, resulting in large jitter, making the stability of the output power supply voltage of the LDO circuit poor. Moreover, the increase in the equivalent resistance of the power transistor PM also means an increase in impedance. The larger impedance will cause more power loss, the working efficiency of the power transistor PM becomes lower, and it will be dissipated in the form of heat, which is not conducive to the thermal management of the chip DDIC.

[0027] That is to say, the voltage difference ΔV between the output voltage Vddr and the input voltage Vin is affected by the load. The heavier the load, the larger the load current, and the larger the voltage difference ΔV. Since Vddr = Vin - ΔV, the output voltage Vddr is lower. For example, see Figure 2The diagram illustrating voltage changes shows that under light load conditions, the output voltage Vddr is close to the input voltage Vin, meaning the voltage difference ΔV between them is small. Under heavy load conditions, the voltage difference ΔV between Vddr and Vin is large. A lower output voltage Vddr degrades the performance of the load circuit, negatively impacting the stability of the circuit system. Furthermore, a lower output voltage Vddr limits the input voltage Vin's operation within the normal operating range (i.e., the linear region), making it difficult to assess the load circuit's withstand voltage.

[0028] This application provides a voltage regulator, such as... Figure 3 As shown, the voltage regulator includes a first control circuit 01 and a first drive circuit 02, with the first control circuit 01 connected to the first drive circuit 02. The input terminal of the voltage regulator is connected to the first drive circuit 02, and the voltage applied to the input terminal is the input voltage of the voltage regulator. The output terminal of the voltage regulator is also connected to the first drive circuit 02, and the voltage output at the output terminal is the output voltage of the voltage regulator.

[0029] The first control circuit 01 outputs a first signal to the first drive circuit 02 when the voltage regulator is operating in the differential voltage region, and outputs a second signal to the first drive circuit 02 when the voltage regulator is operating in the linear region. The driving capability of the first signal is higher than that of the second signal. The driving capability of the signal output by the first control circuit 01 refers to the ability of the first drive circuit 02 to convert the input voltage into an output voltage based on the signal. A higher driving capability means a stronger voltage conversion capability, i.e., a smaller voltage difference between the converted output voltage and the input voltage. For example, if a PMOS transistor is used as the power transistor in the first drive circuit 02, and the PMOS transistor is turned on at a low level, then the driving capability of the first signal being higher than that of the second signal means that the voltage value of the first signal is lower than the voltage value of the second signal.

[0030] The first driving circuit 02 is used to convert the input voltage under the action of a first signal or a second signal, and provide the converted voltage to the output terminal of the voltage regulator; when the voltage regulator is operating in the differential voltage region, the voltage difference between the converted voltage and the input voltage is less than a first threshold. The first threshold can be flexibly set according to the application scenario, and the stable voltage of the voltage regulator refers to the fixed voltage that the voltage regulator stably outputs in the linear region.

[0031] Therefore, the first control circuit can control the driving capability of the output signal according to the working range of the voltage regulator, and then adjust the voltage conversion mode of the first drive circuit. When the voltage regulator is working in the differential voltage range, the voltage difference between the output voltage converted by the first drive circuit and the input voltage is kept within the first threshold, so as to avoid the output voltage from becoming lower due to the load and enhance the stability and reliability of the output voltage in the differential voltage range.

[0032] For example, the first driving circuit 02 is used to convert the input voltage into a first output voltage under the action of a first signal, and provide the first output voltage to the output terminal of the voltage regulator. At this time, the output voltage at the output terminal of the voltage regulator is the first output voltage, and the voltage difference between the first output voltage and the input voltage is less than a first threshold. Under the action of a second signal, it converts the input voltage into a second output voltage, and provides the second output voltage to the output terminal of the voltage regulator. At this time, the output voltage at the output terminal of the voltage regulator is the second output voltage, and the voltage difference between the second output voltage and the stable voltage of the voltage regulator is also less than the first threshold. Thus, when the voltage regulator is operating in the linear region, the output voltage converted by the first driving circuit can maintain the voltage difference between it and the fixed stable voltage within the first threshold, improving the stability and reliability of the voltage regulator throughout the entire operating range.

[0033] In one possible implementation, see Figure 4 The voltage regulator also includes a second control circuit 03 and a second drive circuit 04. The second control circuit 03 outputs a third signal to the second drive circuit 04 when the voltage regulator is operating in the differential voltage region. The second drive circuit 04, under the action of the third signal, converts the input voltage into a third output voltage and provides this third output voltage to the output terminal of the voltage regulator. At this time, the output voltage at the output terminal of the voltage regulator is the sum of the third output voltage and the first output voltage. The voltage difference between the sum of the third output voltage and the first output voltage and the input voltage is less than a second threshold, and the second threshold is less than the first threshold. In this mode, voltage conversion is achieved by superimposing the first drive circuit 02 and the second drive circuit 04, further enhancing the driving capability of converting the input voltage into the output voltage, allowing the output voltage to follow only the input voltage changes, and further reducing the voltage difference between the output voltage and the input voltage.

[0034] In the linear region, since the regulator's output voltage is already stable and will no longer change with the input voltage, no significant driving capability is required. The second control circuit 03 is also used to output a fourth signal to the second drive circuit 04 when the regulator is operating in the linear region. The second drive circuit 04, under the influence of the fourth signal, is also used to stop converting the input voltage into a second output voltage, i.e., to stop providing a third output voltage to the regulator's output terminal. Therefore, after the regulator operates in the linear region, the second drive circuit 04 no longer provides additional driving capability, and the stable output voltage is achieved solely through the first drive circuit 02.

[0035] In this embodiment, both the first driving circuit 02 and the second driving circuit 04 can be implemented using power transistors, including but not limited to NMOS transistors or PMOS transistors. Taking the first driving circuit 02 including a power transistor PM as an example, the power transistor PM is a PMOS transistor. The gate of the power transistor PM is connected to the output terminal of the first control circuit 01, the source of the power transistor PM is connected to the input terminal, and the drain of the power transistor PM is connected to the output terminal. The input terminal receives the input voltage Vin, and the output terminal outputs the output voltage Vddr. The power transistor PM is used to adjust its conduction level under the control of the signal output by the first control circuit 01 to control the voltage value of the output voltage Vddr. Different conduction levels result in different driving capabilities; the stronger the conduction level of the power transistor PM, the larger the output voltage Vddr, and the weaker the conduction level of the power transistor PM, the smaller the output voltage Vddr.

[0036] In one possible implementation, see Figure 5 The first control circuit 01 includes a negative feedback circuit 011, an error amplifier circuit 012, and a first multiplexer (MUX) 1. The first input terminal of the first multiplexer MUX1 is connected to the output terminal of the error amplifier circuit 012, and the second input terminal of the first multiplexer is connected to the signal terminal of the first signal. The negative feedback circuit 011 is used to convert the voltage output from the output terminal of the voltage regulator (i.e., the output voltage of the voltage regulator) into a feedback voltage according to a first ratio, and return the feedback voltage to the error amplifier circuit 012. The first ratio is a positive fraction less than 1. The error amplifier circuit 012 is used to compare the reference voltage with the feedback voltage returned by the negative feedback circuit 011, and output a second signal according to the voltage difference between the reference voltage and the feedback voltage. The first multiplexer MUX1 is used to select the first signal output when the voltage regulator is operating in the voltage difference region, and to select the second signal output when the voltage regulator is operating in the linear region.

[0037] The reference voltage Vref is a fixed voltage value inside the regulator, typically generated by a bandgap reference or a Zener diode. The purpose of Vref is to provide a comparison standard for the error amplifier circuit 012: when the output voltage deviates from the target value (i.e., the stable voltage) due to load changes or input fluctuations, the error amplifier circuit 012 compares the difference between the output voltage divider (i.e., the feedback voltage Vfb) and the reference voltage Vref, dynamically adjusting the driving capability of the first drive circuit 01 to ultimately stabilize the output voltage.

[0038] Optionally, the first selector MUX1 can be a 2-to-1 selector, which includes two input ports (i.e., a first input and a second input). Figure 5 The first input terminal corresponds to port 1, and the second input terminal corresponds to port 0. The 2-to-1 multiplexer selects one signal from the two input ports as the output based on the state of the control signal. For example, when the voltage regulator is operating in the differential voltage region, the 2-to-1 multiplexer selects the first signal input at port 1 as the output; when the voltage regulator is operating in the linear region, it selects the second signal input at port 0 as the output. The first signal can be low.

[0039] In one possible implementation, see [link to previous document]. Figure 5 The voltage regulator also includes a detection circuit 05. The detection circuit 05 is used to detect the operating range of the voltage regulator based on the input voltage. When the voltage regulator is detected operating in the differential voltage region, it sends a first control signal to the first control circuit 01 and the second control circuit 03. When the voltage regulator is detected operating in the linear region, it sends a second control signal to the first control circuit 01 and the second control circuit 03. Optionally, the detection circuit 05 is also used to not send control signals to the first control circuit 01 and the second control circuit 03 when the voltage regulator is detected operating in the cutoff region.

[0040] In this case, the first control circuit 01 is further configured to determine that the voltage regulator is operating in the differential pressure region upon receiving the first control signal, and to determine that the voltage regulator is operating in the linear region upon receiving the second control signal. The second control circuit 03 is further configured to determine that the voltage regulator is operating in the differential pressure region upon receiving the first control signal, and to determine that the voltage regulator is operating in the linear region upon receiving the second control signal.

[0041] according to Figure 1The timing analysis shown indicates that when the input voltage Vin is less than the first voltage threshold V1, the regulator operates in the cutoff region; when the input voltage Vin is greater than or equal to the first voltage threshold V1 and less than the second voltage threshold V2, the regulator operates in the differential voltage region; and when the input voltage Vin is greater than or equal to the second voltage threshold V2, the regulator operates in the linear region. Therefore, the detection circuit 05 can determine the operating range of the regulator based on the range of the input voltage. The first voltage threshold V1 and the second voltage threshold V2 are determined based on the characteristics of the components in the regulator, with the first voltage threshold V1 being less than the second voltage threshold V2.

[0042] In one possible implementation, see Figure 6 The detection circuit 05 includes an input conversion circuit 051 and a comparison circuit 052. The input conversion circuit 051 converts the input voltage into a first voltage. The comparison circuit 052 compares the first voltage with a reference voltage and determines whether the voltage regulator is operating in the differential voltage region or the linear voltage region based on the relationship between the first voltage and the reference voltage. For example, if the first voltage is less than the reference voltage, the voltage regulator is detected to be operating in the differential voltage region, and a first control signal is sent to the first control circuit 01 and the second control circuit 03; if the first voltage is greater than or equal to the reference voltage, the voltage regulator is detected to be operating in the linear voltage region, and a second control signal is sent to the first control circuit 01 and the second control circuit 03.

[0043] The purpose of comparator circuit 052 is to compare the relationship between the input voltage and the stable voltage, which is the fixed output voltage of the regulator after it enters the linear region. If the input voltage is less than the stable voltage, the regulator is operating in the differential voltage region; if the input voltage is greater than or equal to the stable voltage, the regulator is operating in the linear region. During power-up, the output voltage changes, but the reference voltage, serving as the benchmark for the stable voltage, remains a fixed value. Since the reference voltage is a voltage divider of the output voltage, the voltage used for comparison should also be a voltage divider of the input voltage. Therefore, input conversion circuit 051 converts the input voltage to obtain a first voltage, making the relationship between the first voltage and the reference voltage equivalent to the relationship between the input voltage and the stable voltage.

[0044] Optionally, the input conversion circuit 051 includes a resistor voltage divider circuit 0511 and a low-pass filter 0512. The resistor voltage divider circuit 0511 is used to convert the input voltage into a second voltage according to a second ratio, where the second ratio is a positive integer less than 1. The low-pass filter 0512 is used to filter the second voltage to obtain a first voltage. The low-pass filter can be an RC low-pass filter. This application does not limit the structure of the resistor voltage divider circuit 0511. For example, the resistor voltage divider circuit 0511 includes a first resistor and a second resistor. One end of the first resistor is connected to the input terminal of the voltage regulator, and the other end of the first resistor is connected to one end of the second resistor through a node. The other end of the second resistor is connected to ground, and the voltage at the node is the second voltage. The ratio between the second voltage and the input voltage is the ratio of the resistance value of the second resistor to the resistance value of a third resistor, where the third resistance value is the sum of the resistance values ​​of the first and second resistors.

[0045] In one possible implementation, the detection circuit 05 further includes a power-on reset (POR) circuit 053. The POR circuit 053 is used to send a reset signal to the comparator circuit 052 when the input voltage is less than or equal to a first voltage threshold; and to send a reset cancellation signal to the comparator circuit 052 when the input voltage is greater than the first voltage threshold. In this case, the comparator circuit 052, upon receiving the reset signal from the POR circuit 053, enters a reset state, does not compare the first voltage with the reference voltage, and determines that the regulator is operating in the cutoff region; upon receiving the reset cancellation signal from the POR circuit 053, exits the reset state, compares the first voltage with the reference voltage, and determines that the regulator's operating range has entered the differential voltage region.

[0046] The POR (Power Order Reset) is an integrated reset mechanism within the chip, which initializes the system by monitoring changes in the power supply voltage. This reset mechanism includes: when the power supply voltage exceeds a preset threshold, activating an internal delay circuit to maintain the reset state; and sending a reset cancellation signal after the power supply voltage stabilizes. Compared to external reset circuits, the POR uses a comparator structure for threshold detection, requiring only an external pull-up resistor to complete the reset operation. In this embodiment, the preset threshold of the POR circuit 053 is the aforementioned first voltage threshold.

[0047] For example, see Figure 7 The diagram shows a voltage regulator. The first control circuit 01 includes a selector MUX1, an error amplifier EA (corresponding to error amplifier circuit 012), and resistors R1 and R2 (corresponding to negative feedback circuit 011). The first drive circuit 02 includes a power transistor PM. The second control circuit 03 includes a selector MUX2. The second drive circuit 04 includes a power transistor PMI.

[0048] exist Figure 7In the shown voltage regulator, the reference voltage Vref acts on the negative input terminal (-) of the error amplifier EA, and the feedback voltage Vfb acts on the positive input terminal (+) of the error amplifier EA. The error signal Vg (corresponding to the second signal) output by the error amplifier EA and the low level L (corresponding to the first signal) act on two input terminals of MUX1 respectively, and the control signal Sel acts on the selector MUX1 to select the output signal Vg0, and Vg0 is used as the gate control signal of the power transistor PM.

[0049] In addition, two input terminals of the selector MUX2 are respectively connected to the high level H (corresponding to the fourth signal) and the low level L (corresponding to the third signal), and the control signal Sel acts on the selector MUX2 at the same time to output Vg1, and Vg1 is used as the gate control signal of the power transistor PMI. The selector MUX is used to select one of the two input signals as the output according to the state of the control signal. For example, when the control signal Sel is at the high level, the signal at port 1 is selected for output, and when the control signal Sel is at the low level, the signal at port 0 is selected for output.

[0050] During the power-on process, when the voltage regulator operates in the cut-off region (Vin < V1), the output voltage Vddr has not started to be output, that is, the voltage value of the output voltage Vddr remains 0 continuously, so the state of the control signal Sel has no influence on the output voltage.

[0051] When the voltage regulator operates in the differential pressure region (V1 ≥ Vin < V2), the control signal Sel is at the low level, then Vg0 = L, Vg1 = L, and the voltage regulator turns on the driving ability enhancement mode. In the driving ability enhancement mode, the gates of the power transistors PM and PMI are both connected to the low level and are in the saturation region, the power transistors PM and PMI are both turned on, and the power transistors PM and PMI supply power to the load at the same time to enhance the driving ability of the voltage regulator, making the differential pressure between the output voltage Vddr and the input voltage Vin smaller. Among them, since the power transistor PM is no longer in the linear working region but in the saturation region, there is no large equivalent resistance in the power transistor PM, so that the output voltage Vddr is no longer affected by the load.

[0052] When the voltage regulator operates in the linear region (V2 ≥ Vin), the control signal Sel jumps to the high level, then Vg0 = Vg, Vg1 = H, and the voltage regulator turns off the driving ability enhancement mode. In the driving ability enhancement mode off state, the voltage regulator is in its original normal working mode, that is, the power transistor PMI is in the cut-off region, no current flows between the drain and source of the power transistor PMI, and the power transistor PM is controlled by the signal Vg output by the error amplifier EA, and the voltage regulator outputs a fixed output voltage Vddr.

[0053] The control signal Sel is generated by the aforementioned detection circuit 05. When the voltage regulator operates in the differential voltage region, the control signal Sel is low (corresponding to the first control signal); when the voltage regulator operates in the linear region, the control signal Sel is high (corresponding to the second control signal). For example, Figure 8 This is a structural diagram of another detection circuit 05 provided in an embodiment of this application. (See diagram below.) Figure 8 As shown, the resistor divider circuit 0511 includes resistors R3 and R4, the low-pass filter (LPF) 0512 includes capacitor C and resistor R5, the comparator circuit 052 includes a comparator (COMP), and the POR circuit 053 includes a POR circuit.

[0054] The input voltage Vin is divided by a resistor series consisting of resistors R3 and R4 to obtain a divided voltage Vr. For example, Vr = Vin * [R4 / (R3 + R4)]. The divided voltage Vr varies with the input voltage Vin. After being processed by the LPF, the divided voltage Vr outputs a filtered voltage Vc. The LPF uses the impedance voltage divider characteristic of resistor R5 and capacitor C to remove high-frequency ripple from the divided voltage Vr, making the output filtered voltage Vc more stable. The filtered voltage Vc is connected to the positive input terminal (+) of the comparator COMP, and the reference voltage Vref is connected to the negative input terminal (-) of the comparator COMP. The comparator COMP is also connected to the input voltage Vin and the signal Vrst output from the power-on reset (POR) circuit. The signal Vrst is used to control the operating state of the comparator COMP.

[0055] Specifically, the POR circuit outputs a signal Vrst to the comparator COMP based on the input voltage Vin. Optionally, when the input voltage Vin is less than the first threshold voltage V1, the POR circuit sends a low-level signal Vrst (corresponding to a reset signal) to the comparator COMP, at which point the regulator is in the cutoff region; when the input voltage Vin is greater than or equal to the first threshold voltage V1, the POR circuit sends a high-level signal Vrst (corresponding to a reset cancellation signal) to the comparator COMP, at which point the regulator's operating range enters the differential voltage region or the linear region.

[0056] Comparator COMP is used to not work when receiving a low-level signal Vrst, and output the input voltage Vin as the control signal Sel, that is, Sel = Vin; it works normally when receiving a high-level signal Vrst, and compares the filtered voltage Vc input at the positive and negative ends with the reference voltage Vref. Among them, the filtered voltage Vc changes with the input voltage Vin, and the reference voltage Vref is a fixed value. When the input voltage Vin is less than the second threshold voltage V2, the filtered voltage Vc is less than the reference voltage Vref. At this time, the control signal Sel is at a low level, enabling the regulator to turn on the enhanced drive capability mode; when the input voltage Vin is greater than or equal to the second threshold voltage V2, the filtered voltage Vc is greater than or equal to the reference voltage Vref, and the control signal Sel is at a high level, enabling the regulator to turn off the enhanced drive capability mode.

[0057] Next, in combination with Figure 9 the shown working flow chart and Figure 10 the shown signal timing diagram, the working process of the regulator provided in the embodiment of the present application during the power-on and power-off process of the input voltage is described. Among them, Figure 10 the shown signal timing diagram is the signal timing diagram of the regulator in the heavy load state.

[0058] First step, the input voltage Vin starts to power on, and the regulator is in the cut-off region stage, and the output voltage Vddr is at a low level.

[0059] In the cut-off region stage during this power-on process, the input voltage Vin starts to power on from a low level. At this time, the input voltage Vin is less than or equal to the first threshold voltage V1, that is, Vin ≤ V1, and the POR circuit triggers a low-level signal Vrst. The comparator COMP enters the reset state based on Vrst being at a low level, and the output control signal Sel changes with the input voltage. However, since the regulator is in the cut-off region stage and the output voltage Vddr has not started to output, the regulator is not controlled by the control signal Sel.

[0060] Second step, the input voltage Vin rises to the first threshold voltage V1, and the regulator is in the voltage difference region stage, and the output voltage Vddr rises with the input voltage Vin.

[0061] In the voltage difference region stage during this power-on process, the input voltage Vin is greater than or equal to the first threshold voltage V1 and less than the second threshold voltage V2, that is, V1 ≤ Vin < V2. At this time, the POR circuit outputs a high-level signal Vrst. The comparator COMP starts to detect the working range of the input voltage Vin. If the input voltage Vin is less than the second threshold voltage V2, the filtered voltage Vc is less than the reference voltage Vref, causing the control signal Sel output by the comparator COMP to jump to a low level.

[0062] When the control signal Sel is low, selector MUX1 selects a low-level L output, i.e., Vg0=L, and selector MUX2 selects a low-level L output, i.e., Vg1=L. The regulator then activates the enhanced drive capability mode. This ensures that in the differential voltage range, the output voltage Vddr only follows the input voltage Vin, and even under heavy load, the voltage difference between the output voltage Vddr and the input voltage Vin remains small.

[0063] In the third step, the input voltage Vin continues to rise and exceeds the second threshold voltage V2. The regulator is in the linear region and the output voltage Vddr is stable.

[0064] During the linear region, the input voltage Vin is greater than or equal to the second threshold voltage V2, i.e., Vin≥V2. At this time, the POR circuit still outputs a high-level signal Vrst. The comparator COMP continues to detect the operating range of the input voltage Vin. If the input voltage Vin is greater than the second threshold voltage V2, the filter voltage Vc is greater than the reference voltage Vref, causing the comparator COMP to output the control signal Sel to jump to a high level.

[0065] When the control signal Sel is high, selector MUX1 selects the output signal Vg of error amplifier EA, i.e., Vg0 = Vg, and selector MUX2 selects the high-level output H, i.e., Vg1 = H. The regulator then disables the drive capability enhancement mode. As a result, in the linear region, the regulator can output a stable power supply voltage, i.e., the output voltage Vddr is a fixed value.

[0066] In the fourth step, the input voltage Vin starts to power down and falls below the second threshold voltage V2. The regulator is in the differential voltage range, and the output voltage Vddr decreases with the input voltage Vin.

[0067] During the voltage difference region phase of the power-down process, the POR circuit outputs a high-level signal Vrst. The comparator COMP detects the operating range of the input voltage Vin. If the input voltage Vin is less than the second threshold voltage V2, the filter voltage Vc is less than the reference voltage Vref, causing the control signal Sel output by the comparator COMP to jump to a low level. When the control signal Sel is low, the regulator activates its enhanced drive capability mode, ensuring that the output voltage Vddr follows only the input voltage Vin. Even under heavy load, the voltage difference between the output voltage Vddr and the input voltage Vin remains small.

[0068] In the fifth step, the input voltage Vin continues to drop to the first threshold voltage V1, the regulator is in the cutoff region, and the output voltage Vddr is low.

[0069] During this cutoff phase, the POR circuit triggers a low-level signal Vrst. The comparator COMP, based on Vrst being low, enters a reset state, meaning it loses its control capability. Consequently, the output voltage Vddr remains low until the input voltage Vin is powered off.

[0070] In summary, the voltage regulator provided in this application, by changing the operating state of the power transistors and increasing the number of power transistors, can enhance the driving capability of the power transistors in the differential voltage region, reduce the impact of load changes on the output voltage, and ensure that there is no large voltage difference between the output voltage and the input voltage, thus improving the stability of the output voltage and enhancing the robustness of the voltage regulator. Furthermore, when the voltage difference between the output voltage and the input voltage is small, widening the lower limit of the normal operating range of the input voltage in the voltage regulator helps the DDIC operate normally under lower input voltage conditions. In addition, by providing a low-level signal as a drive signal to the power transistors, the operating state of the power transistors is in the saturation operating range, reducing the on-resistance of the power transistors, reducing power loss in the differential voltage region, which helps improve the operating efficiency of the voltage regulator, reduces heat dissipation from the power transistors, extends the lifespan of the voltage regulator, and lowers the operating temperature of the chip.

[0071] This application also provides a chip, which includes a load and, as shown in the embodiments, a chip including ... Figure 3-5 The voltage regulator shown in either 7 or 8. The voltage regulator is connected to the load and is used to provide an output voltage to the load so as to drive the load to operate.

[0072] Optionally, the chip is a display driver chip, such as a DDIC. Driven by a voltage regulator, the DDIC reliably displays images on a connected display panel via load control.

[0073] It is understandable that, since the chip has essentially the same technical effect as the aforementioned voltage regulator, for the sake of brevity, the technical effect of the chip will not be described again here.

[0074] This application also provides an electronic device, which includes the above-described chip; or, the electronic device includes as follows: Figure 3-5 The voltage regulator shown in either 7 or 8. Optionally, the electronic device can be a display device. For example, it can be a mobile phone, computer, or other display device.

[0075] It is understandable that, since the electronic device has essentially the same technical effect as the aforementioned voltage regulator, for the sake of brevity, the technical effect of the electronic device will not be described again here.

[0076] The terms "first," "second," "third," and "fourth," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0077] In this document, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0078] The above description is merely an optional embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the principles of this application should be included within the protection scope of this application.

Claims

1. A voltage regulator characterized by comprising: The voltage stabilizer comprises a first control circuit and a first driving circuit; The first control circuit is configured to output a first signal to the first driving circuit when the voltage stabilizer works in a differential voltage region, and output a second signal to the first driving circuit when the voltage stabilizer works in a linear region, wherein the driving capability of the first signal is higher than that of the second signal; The first driving circuit is configured to convert the input voltage under the action of the first signal or the second signal, and provide the converted voltage to an output terminal of the voltage stabilizer; When the voltage stabilizer works in the differential voltage region, the differential voltage between the converted voltage and the input voltage is less than a first threshold value.

2. The voltage regulator of claim 1, wherein The first driving circuit is configured to convert the input voltage into a first output voltage under the action of the first signal, and provide the first output voltage to the output terminal of the voltage stabilizer; The first driving circuit is configured to convert the input voltage into a first output voltage under the action of the first signal, and provide the first output voltage to the output terminal of the voltage stabilizer; 3. The voltage regulator of claim 2, wherein, The voltage stabilizer further comprises a second control circuit and a second driving circuit; The second control circuit is configured to output a third signal to the second driving circuit when the voltage stabilizer works in the differential voltage region; The second driving circuit is configured to convert the input voltage into a third output voltage under the action of the third signal, and provide the third output voltage to the output terminal of the voltage stabilizer, wherein the differential voltage between the sum of the third output voltage and the first output voltage and the input voltage is less than a second threshold value, and the second threshold value is less than the first threshold value.

4. The voltage regulator of claim 3, wherein, The second control circuit is further configured to output a fourth signal to the second driving circuit when the voltage stabilizer works in the linear region; The second driving circuit is further configured to stop converting the input voltage into the third output voltage under the action of the fourth signal.

5. The voltage regulator of claim 1, wherein, The first control circuit comprises a negative feedback circuit, an error amplification circuit, and a first gate, wherein a first input terminal of the first gate is connected with an output terminal of the error amplification circuit, and a second input terminal of the first gate is connected with a signal terminal of the first signal; The negative feedback circuit is configured to convert the voltage output by the output terminal of the voltage stabilizer into a feedback voltage in a first proportion; The error amplification circuit is configured to compare a reference voltage with the feedback voltage, and output the second signal according to the differential voltage between the reference voltage and the feedback voltage; The first gate is configured to select the first signal output when the voltage stabilizer works in the differential voltage region, and select the second signal output when the voltage stabilizer works in the linear region.

6. Regulator according to any of claims 1-5, characterized in that The voltage regulator further includes a detection circuit; the detection circuit is used to detect the operating range of the voltage regulator based on the input voltage, and when the voltage regulator is detected to be operating in the differential voltage region, to send a first control signal to the first control circuit; and when the voltage regulator is detected to be operating in the linear region, to send a second control signal to the first control circuit. The first control circuit is further configured to determine, upon receiving the first control signal, that the voltage regulator is operating in the differential pressure region; and upon receiving the second control signal, to determine that the voltage regulator is operating in the linear region.

7. The voltage regulator of claim 6, wherein, The detection circuit includes an input conversion circuit and a comparison circuit; The input conversion circuit is used to convert the input voltage into a first voltage; The comparison circuit is used to compare the first voltage with the reference voltage, and determine whether the voltage regulator operates in the differential voltage region or the linear region based on the relationship between the first voltage and the reference voltage.

8. The voltage regulator of claim 7, wherein, The input conversion circuit includes a resistor voltage divider circuit and a low-pass filter; The resistor voltage divider circuit is used to convert the input voltage into a second voltage according to a second ratio; The low-pass filter is used to filter the second voltage to obtain the first voltage.

9. Regulator according to claim 7 or 8, characterized in that The detection circuit also includes a power-on reset circuit; The power-on reset circuit is used to send a reset signal to the comparator circuit when the input voltage is less than or equal to a first voltage threshold, and to send a reset cancellation signal to the comparator circuit when the input voltage is greater than the first voltage threshold. The comparison circuit is configured to enter a reset state upon receiving the reset signal, and not compare the first voltage with the reference voltage. Upon receiving the reset cancellation signal, the system exits the reset state and compares the first voltage with the reference voltage.

10. A chip, characterized by The chip includes: a load, and a voltage regulator as described in any one of claims 1 to 9; The voltage regulator is connected to the load and is used to provide an output voltage to the load so as to drive the load to work.

11. An electronic device, comprising: The electronic device includes the chip as described in claim 10.

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