Power supply system, method of controlling power supply system, and electronic device

Abstract

A power supply system, a method for controlling the power supply system and an electronic device are provided. The power supply system comprises: a power supply chip configured to convert a received input voltage into an output voltage; and a voltage dividing circuit configured to output a first voltage dividing signal to the power supply chip when the input voltage is greater than or equal to a first voltage threshold, so as to control the power supply chip to provide the output voltage externally; and output a second voltage dividing signal to the power supply chip when the input voltage is less than a second voltage threshold, so as to control the power supply chip to stop providing the output voltage externally, wherein the first voltage threshold is less than the second voltage threshold. Embodiments of the present application achieve a hysteresis function by using a simple voltage dividing circuit, thereby saving a hysteresis comparator and reducing the complexity of the power supply system.

Description

Technical Field

[0001] This application relates to the field of electronic devices, and more specifically, to a power supply system, a method for controlling a power supply system, and an electronic device. Background Technology

[0002] Power supply systems provide a stable and reliable power supply to the various load devices in electronic devices. Any instability in power supply can severely affect these devices. For example, fluctuations in input voltage around a voltage threshold can cause frequent start-stop cycles for components. Power supply systems typically employ hysteresis comparator circuits to reduce the impact of input voltage fluctuations. Summary of the Invention

[0003] This application provides a power supply system, a method for controlling the power supply system, and an electronic device. The various aspects involved in this application will be described below.

[0004] In a first aspect, a power supply system is provided, comprising: a power chip for receiving an input voltage and converting the input voltage into an output voltage of the power chip; and a voltage divider circuit for outputting a first voltage divider signal to the power chip when the input voltage is greater than or equal to a first voltage threshold, thereby controlling the power chip to provide the output voltage; and for outputting a second voltage divider signal to the power chip when the input voltage is less than a second voltage threshold, thereby controlling the power chip to stop providing the output voltage, wherein the first voltage threshold is less than the second voltage threshold.

[0005] In a second aspect, an electronic device is provided, comprising: a load device; and a power supply system, the power supply system comprising: a power chip for receiving an input voltage and converting the input voltage into an output voltage of the power chip; and a voltage divider circuit for outputting a first voltage divider signal to the power chip when the input voltage is greater than or equal to a first voltage threshold, thereby controlling the power chip to provide the output voltage to the load device; and for outputting a second voltage divider signal to the power chip when the input voltage is less than a second voltage threshold, thereby controlling the power chip to stop providing the output voltage to the load device, wherein the first voltage threshold is less than the second voltage threshold.

[0006] Thirdly, a method for controlling a power supply system is provided, comprising: when the input voltage of the power supply system is greater than or equal to a first voltage threshold, a voltage divider circuit outputs a first voltage divider signal to a power chip to control the power chip to provide an output voltage; when the input voltage is less than a second voltage threshold, the voltage divider circuit outputs a second voltage divider signal to the power chip to control the power chip to stop providing the output voltage; wherein the first voltage threshold is less than the second voltage threshold.

[0007] The embodiments of this application utilize a simple voltage divider circuit to achieve the hysteresis function, eliminating the need for a hysteresis comparator and reducing the complexity of the power supply system. Attached Figure Description

[0008] Figure 1 This is a schematic diagram of a power supply system that includes a hysteresis comparator circuit.

[0009] Figure 2 yes Figure 1 The diagram shows the relationship between the input voltage and output voltage of the power supply system.

[0010] Figure 3 yes Figure 1 A schematic diagram of the hysteresis comparator circuit.

[0011] Figure 4 This is a schematic diagram of the power supply system provided in the embodiments of this application.

[0012] Figure 5 yes Figure 4 Example circuit structure diagram of the first pin.

[0013] Figure 6 yes Figure 4 The circuit structure of the power supply system shown is an example diagram.

[0014] Figure 7 This is a schematic diagram of the structure of the electronic device provided in the embodiments of this application.

[0015] Figure 8 This is a flowchart illustrating the method for controlling a power supply system provided in an embodiment of this application.

[0016] Figure 9 yes Figure 8 The flowchart illustrates one possible implementation of the method shown. Detailed Implementation

[0017] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0018] With the development of technology, the application of modern electronic devices is becoming increasingly widespread, and the functions of electronic devices are becoming more and more numerous. It should be noted that the electronic devices mentioned in the embodiments of this application are electrical devices composed of microelectronic devices, referring to devices that can be composed of electronic components such as integrated circuits, transistors, and vacuum tubes, and that function using electronic technology (including software). Electronic devices can be referred to as terminals, portable terminals, mobile terminals, communication terminals, portable communication terminals, portable mobile terminals, touch screens, etc. For example, electronic devices can be smartphones, portable phones, game consoles, televisions, display units, head-up displays for vehicles, laptop computers, personal computers (PCs), personal media players (PMPs), personal digital assistants (PDAs), power banks (power banks, travel chargers), drones, e-books, smart electronic devices (such as watches, bracelets, smart glasses, robot vacuums, etc.), and small electronic products (such as wireless headphones, Bluetooth speakers, electric toothbrushes, rechargeable wireless mice), etc. Electronic devices can also be portable communication terminals with wireless communication capabilities and pocket-sized designs. Furthermore, electronic devices can be flexible devices or flexible display devices. Electronic devices can communicate with external electronic devices, such as servers, or perform operations through interoperability with external electronic devices. For example, an electronic device can send images captured by a camera and / or location information detected by a sensor unit to a server via a network.

[0019] The various functional modules within electronic devices have high requirements for the stability of their input power supply, necessitating minimizing the impact of input voltage fluctuations. Power supply chips provide a stable and reliable power supply to these modules; any instability in the power supply can severely affect them. For example, fluctuations in input voltage near a threshold can cause frequent component restarts. Therefore, power management chips typically require significant input voltage hysteresis to effectively prevent continuous restarts caused by minute changes in input voltage, thereby improving the stability of the power supply system. Thus, to reduce the impact of input voltage fluctuations, power supply systems are usually equipped with hysteresis circuits.

[0020] Hysteresis circuits (HC), also known as Schmitt trigger circuits (STC), are widely used due to their ability to filter out interference and noise. Hysteresis circuits can delay the input voltage of power supply chips, thereby improving the stability of the power supply chip's operation. For ease of understanding, the following example uses a commonly used DC power management chip to illustrate the structure and working principle of the hysteresis circuit provided by related technologies in more detail. It should be noted that... Figure 1 This is merely one example of a power system, and the embodiments described in this application are not limited to this one. Figure 1 The power supply system shown is illustrated. In fact, the embodiments of this application can be applied to any type of power supply system that has a hysteresis requirement for the input voltage.

[0021] Figure 1 This is a schematic diagram of a power supply system that includes a hysteresis comparator circuit. For example... Figure 1 As shown in the figure, reference numeral 110 indicates the DC power management chip. This DC power management chip 110 has a voltage input pin for receiving the input voltage (i.e., Figure 1 IN pin), enable pin (i.e. Figure 1 The EN pin and voltage output pin (i.e.) Figure 1 (SW pin in the diagram). The input voltage range of the IN pin is 3V-22V, and the output voltage of the SW pin is V. out For a stable 3.3V, the threshold voltage V of the EN pin is... th The voltage is 1.2V (meaning that when the voltage at the EN pin reaches 1.2V, the power chip starts outputting voltage; when the voltage at the EN pin is lower than 1.2V, the power chip stops outputting voltage).

[0022] When using it, it is usually desirable to have an input voltage V. in There is a relatively large hysteresis. Input voltage V in With output voltage V out The correspondence is as follows Figure 2 As shown. When enabled, when V in When the voltage exceeds the turn-on threshold, the power chip starts outputting voltage; when it is off, when V... in When the voltage is below the shutdown threshold, the power chip stops outputting voltage.

[0023] Combination Figure 2 The input voltage V shown in With output voltage V out The correspondence, Figure 1 The input hysteresis process of the power supply system shown is as follows:

[0024] When the input voltage gradually increases from 0V to the turn-on threshold VH Before (12V), the voltage at the EN pin is less than the threshold voltage of 1.2V, and the output voltage is V. OL (0V). When the input voltage increases to the turn-on threshold V. H At (12V), the voltage at the EN pin is 1.2V, and the output voltage instantly increases to V. OH (3.3V). When the input voltage continues to increase to 22V, the voltage at the EN pin is greater than the threshold voltage of 1.2V, and the output voltage remains at V. OH (3.3V). When the input voltage gradually decreases to the shutdown threshold V L Before (4.8V), the voltage at the EN pin is no lower than the threshold voltage of 1.2V, and the output voltage is always V. OH (3.3V). When the input voltage is less than the shutdown threshold V L At 4.8V, the voltage at the EN pin is less than the threshold voltage of 1.2V, and the output voltage drops instantaneously to V. OL (0V).

[0025] Hysteresis comparator circuits are typically used to reduce the impact of input voltage fluctuations on the output voltage, thus achieving the hysteresis function.

[0026] like Figure 1 As shown, the input terminal of the hysteresis comparator circuit 120 is connected to the input terminal of the DC power management chip 110. After extracting a portion of the input voltage signal, comparing and judging it, the output voltage output signal is sent to the EN terminal of the power management chip 110.

[0027] Figure 3 yes Figure 1 The schematic diagram of the hysteresis comparator circuit shown is as follows: Figure 3 As shown, the hysteresis comparator circuit may include: comparator 121, power supply module 122, first resistor R1 and second resistor R2.

[0028] The output V of the hysteresis comparator circuit out With input V in The relationship is not linear; the critical condition for the output voltage to switch on and off is that the threshold voltage ≈ the reference voltage V. ref The threshold voltage V of the input voltage can be obtained. H and the closing threshold V L for:

[0029]

[0030]

[0031] To implement output voltage hysteresis using comparator 121, a reference voltage V needs to be set. refA power supply module 122 for a comparator. Therefore, the output of comparator 121 is also affected by the power supply, and comparator 121 is sensitive to the reference voltage V. ref The accuracy requirements are high.

[0032] The power supply rejection ratio (PSRR) is a quantity used to describe the influence of the power supply on the output signal. PSRR represents the ratio of the voltage gains obtained when the input and output power supplies are considered as two independent signal sources. The larger the PSRR, the less the output signal is affected by the power supply.

[0033] Therefore, the hysteresis comparator circuit uses more components, which increases the circuit complexity, places higher demands on the power supply and reference voltage, and makes the stability of the power supply system susceptible to external interference.

[0034] Figure 4 This is a schematic diagram of a power supply system provided in an embodiment of this application. The power supply system includes a power chip 210 and a voltage divider circuit 220.

[0035] The power chip 210 may sometimes be referred to as a power management chip. In some embodiments, the power chip may be a buck converter chip that performs a buck conversion function. As an example, the power chip may be a DC power management chip 110.

[0036] In some implementations, the power supply chip can be a power supply chip that performs DC / DC conversion. In other implementations, the power supply chip can be a power supply chip that performs DC / AC conversion.

[0037] The power chip 210 can receive an input voltage and convert it into its output voltage. This input voltage can be within a certain voltage range (hereinafter referred to as the first voltage range for ease of description). The start and end voltages of this first voltage range depend on the type of power chip and the specific application scenario, and this embodiment does not specifically limit them. Taking a DC power management chip as an example, the first voltage range can be 3V-22V. That is, the start voltage of the input voltage of the power chip can be 3V, and the end voltage can be 22V.

[0038] The input voltage of the power supply chip 210 can have a hysteresis voltage range. This hysteresis voltage range can be defined by a first voltage threshold and a second voltage threshold. That is, the hysteresis voltage range can be located between the first voltage threshold and the second voltage threshold. The first voltage threshold can be greater than the second voltage threshold.

[0039] This first threshold voltage can also be referred to as the turn-on voltage (or turn-on threshold) of the power supply chip 210. Taking the DC power management chip 110 as an example, this first threshold voltage can be, for example, 12V.

[0040] The second threshold voltage can also be referred to as the shutdown voltage (or shutdown threshold) of the power supply chip 210. Taking the DC power management chip 110 as an example, this second threshold voltage could be, for example, 4.8V. The power supply chip 210 may have a voltage input pin (or pin, terminal). This voltage input pin can be used to receive an input voltage. In some embodiments, the voltage input pin can be referred to as the IN pin.

[0041] The power chip 210 may also have an enable pin, also known as the EN pin. The enable pin of the power chip 210 has a certain threshold voltage. This threshold voltage controls the start and stop of the power chip 210. For example, when the voltage of the enable pin is greater than or equal to the threshold voltage, the power chip 210 can start providing output voltage; when the voltage of the enable pin is less than the threshold voltage, the power chip 210 can stop providing output voltage. Taking the DC power management chip 110 as an example, this threshold voltage could be, for example, 1.2V.

[0042] The power chip 210 may also include an output pin. The output pin of the power chip 210 can be used to output a DC voltage. Taking the DC power management chip 110 as an example, the output voltage of the output pin of this power chip is a 3.3V DC voltage. Of course, in some embodiments, the output pin of the power chip 210 can also be used to output an AC voltage.

[0043] The power chip 210 may also include a first pin. This first pin can have multiple states. For example, the first pin can have a high-resistance state and a low-resistance state (or a pull-down state). The high-resistance state can also be understood as an off state or a cut-off state. When the first pin is in a high-resistance state, it is disconnected from the internal circuitry. The low-resistance state can also be understood as a conducting state. When the first pin is in a low-resistance state, it is conducting with the internal circuitry.

[0044] The first pin can be a newly introduced pin in the power chip 210 to implement the hysteresis function, or it can reuse an existing pin in the power chip 210. For example, the first pin can be the power good (PG) pin in the power chip 210.

[0045] The following is combined Figure 5 Taking the first pin as the PG pin as an example, a more detailed explanation of the specific implementation of the first pin will be given.

[0046] Figure 5 yes Figure 1A schematic diagram of the PG pin circuit of the power supply chip. (See diagram below.) Figure 5 As shown, the PG pin of the DC power management chip is an open-drain output pin of an internal comparator. The output of the PG pin indicates whether the chip output is normal.

[0047] An open-drain circuit is a circuit that outputs a low level from the drain of a MOSFET. An open-drain output can only output a low level; a pull-up resistor is required to output a high level.

[0048] The PG pin is controlled by the DC power management chip itself and can have three states. It will cut off the MOSFET, in which case the PG pin remains in a high-impedance state; if an external pull-up resistor is connected to the PG pin to the internal bias supply VCC pin (a pin of the DC power management chip), then when the voltage V on the feedback pin... FB The signal is higher than the reference voltage V REF At 92% of its maximum, the PG pin is pulled high after a 200µs delay. The resistance from the power supply to the device pin is a pull-up resistor; the pin is high when no sensor is connected or under high impedance. During normal operation, when the voltage V on the feedback pin... FB The signal is below the reference voltage V REF When the voltage drops below 87%, the PG pin is pulled low after a 50µs delay. If the EN pin goes low (voltage less than 1.2V), the PG pin will be pulled low immediately. The PG pin will also be pulled low immediately if over-temperature protection (OTP), under-voltage lockout (UVLO), or output over-voltage protection occurs.

[0049] When the voltage at the enable pin is greater than or equal to the threshold voltage of the enable pin, the EN pin controls the power chip to provide an output voltage, and the PG pin is in a high-impedance state. When the voltage at the enable pin of the power chip is less than the threshold voltage of the enable pin, the power chip stops providing an output voltage, and the PG pin is in a pulled-down state.

[0050] See also Figure 4 The voltage divider circuit 220 is connected to the power supply chip 210. For example, the voltage divider circuit 220 can be connected to the voltage input pin, the enable pin, and the first pin mentioned above of the power supply chip 210.

[0051] The voltage divider circuit 220 can be used to divide the input voltage and control the power supply chip 210 to start or stop providing output voltage. When the input voltage is greater than or equal to a first voltage threshold, the voltage divider circuit 220 outputs a first voltage divider signal to the power supply chip 210 to control the power supply chip 210 to provide output voltage. When the input voltage is less than a second voltage threshold, the voltage divider circuit 220 outputs a second voltage divider signal to the power supply chip 210 to control the power supply chip 210 to stop providing output voltage, wherein the first voltage threshold is less than the second voltage threshold.

[0052] When the input voltage is greater than or equal to the first voltage threshold, the first pin can be in the high-impedance state mentioned above, and the voltage divider circuit 220 can output the first voltage divider signal to the power chip 210; when the input voltage is less than the second voltage threshold, the first pin can be in the low-impedance state mentioned above, and the voltage divider circuit can output the second voltage divider signal to the power chip 210.

[0053] The voltage divider circuit is also used to control the voltage of the enable pin of the power supply chip to be less than the threshold voltage as the input voltage increases from the initial voltage to the first voltage threshold. When the input voltage decreases from the termination voltage to the second voltage threshold, the voltage of the enable pin of the power supply chip is controlled to be greater than or equal to the threshold voltage.

[0054] In some implementations, such as Figure 6 As shown, the voltage divider circuit may include a first resistor, a second resistor, and a third resistor. The first, second, and third resistors are connected in series between the input IN pin and ground. The output of the voltage divider circuit is located between the first and second resistors, and the PG pin is connected between the second and third resistors.

[0055] When the PG pin is in a high-impedance state, the first, second, and third resistors divide the input voltage, causing the voltage divider circuit to output a first voltage divider signal. When the PG pin is in a low-impedance state, the first and second resistors divide the input voltage, causing the voltage divider circuit to output a second voltage divider signal.

[0056] In some implementations, the first resistor, the second resistor, and the third resistor should satisfy the following formula:

[0057]

[0058]

[0059] Where R1 represents the first resistor, R2 represents the second resistor, R3 represents the third resistor, and U th U represents the threshold voltage of the enable pin. H U represents the first voltage threshold. L This indicates the second voltage threshold.

[0060] This embodiment utilizes a simple voltage divider circuit to output a first voltage divider signal and a second voltage divider signal to the power supply chip, forming a hysteresis range with turn-on and turn-off thresholds for the power supply chip, thus reducing the impact of input voltage fluctuations on output performance. This embodiment eliminates the need for a hysteresis comparator circuit, reducing circuit complexity, providing good circuit stability, and reducing susceptibility to external interference, offering significant advantages in accuracy and stability.

[0061] Figure 6 yes Figure 4 A schematic diagram of one possible implementation of a power supply system. Figure 6 This paper uses a DC power management chip as an example to introduce a power system with hysteresis function according to an embodiment of this application. Figure 6 As shown, the power supply system includes a power chip 310 and a voltage divider circuit 320.

[0062] The power chip 310 receives the input voltage and converts it to output a voltage. This power chip can be a DC power management chip 110, with an input voltage IN pin (or lead / terminal) and a voltage output SW pin. The input voltage of the IN pin has a specific range, which can be 3V-22V. That is, the starting voltage of the power chip's input voltage can be 3V (the absolute starting voltage can be 0V), and the ending voltage can be 22V.

[0063] The input voltage of the power supply chip 310 can have a hysteresis voltage range. This hysteresis voltage range can be defined by a first voltage threshold and a second voltage threshold.

[0064] The first threshold voltage can also be referred to as the turn-on voltage (or turn-on threshold) of the power supply chip 310, and this first threshold voltage can be 12V. The second threshold voltage can also be referred to as the turn-off voltage (or turn-off threshold) of the power supply chip 310, and this second threshold voltage can be 4.8V. The output SW pin can output a stable DC voltage signal, with an output voltage of 3.3V.

[0065] The power chip 310 also includes a first pin, which can be a PG pin, connected to the voltage divider circuit 320. The PG pin is an open-drain output pin of an internal comparator, and the output of the PG pin indicates whether the chip output is normal.

[0066] The power chip 310 also has an EN pin, which is the enable pin of the power chip and has a threshold voltage of 1.2V.

[0067] The PG pin is controlled by the DC power management chip and can have three states. It will cut off the MOSFET, in which case the PG pin remains in a high-impedance state; if an external pull-up resistor is connected to the PG pin to the internal bias supply VCC pin, then when the voltage V on the feedback pin... FB The signal is higher than the reference voltage V REF (see Figure 5 At 92% of its maximum voltage, the PG pin is pulled high after a 200µs delay. The resistance from the power supply to the device pin is a pull-up resistor, and the pin is high when no sensor is connected or under high impedance. During normal operation, when the voltage V on the feedback pin... FB The signal is below the reference voltage V REF When the voltage drops below 87%, the PG pin is pulled low after a 50µs delay. If the EN pin goes low (i.e., the voltage is less than 1.2V), the PG pin will be pulled low immediately. The PG pin will also be pulled low immediately if over-temperature protection, input undervoltage lockout, or output overvoltage protection occurs.

[0068] When the voltage at the enable pin is greater than or equal to the threshold voltage of the enable pin, the EN pin controls the power chip to provide an output voltage, and the PG pin is in a high-impedance state. When the voltage at the enable pin of the power chip is less than the threshold voltage of the enable pin, the power chip stops providing an output voltage, and the PG pin is in a low-impedance state.

[0069] The voltage divider circuit can be connected to the voltage input pins IN, EN, and PG of the power supply chip to divide the input voltage and control the power supply chip 310 to start or stop providing output voltage. The voltage divider circuit 320 can provide a first voltage divider signal or a second voltage divider signal to the enable pin of the power supply chip 310. When the input voltage is greater than or equal to the voltage turn-on threshold of 12V, the voltage divider circuit 320 outputs the first voltage divider signal to the power supply chip 310 to control the power supply chip 310 to provide output voltage. When the input voltage is less than the voltage turn-off threshold of 4.8V, it outputs the second voltage divider signal to the power supply chip 310 to control the power supply chip 310 to stop providing output voltage.

[0070] When the input voltage is greater than or equal to the first voltage threshold, the first pin can be in a high-impedance state; when the input voltage is less than the second voltage threshold, the first pin can be in a low-impedance state. Therefore, when the PG pin is in a high-impedance state, the voltage divider circuit 320 outputs a first voltage divider signal to the power supply chip; when the PG pin is pulled low, the voltage divider circuit outputs a second voltage divider signal to the power supply chip.

[0071] The voltage divider circuit is also used to control the voltage of the enable pin of the power supply chip to be less than the threshold voltage of 1.2V when the input voltage increases from the initial voltage of 0V to the turn-on threshold of 12V, and to control the voltage of the enable pin of the power supply chip to be greater than or equal to the threshold voltage of 1.2V when the input voltage drops from the termination voltage of 22V to the voltage turn-off threshold of 4.8V.

[0072] like Figure 6 As shown, the voltage divider circuit 320 may include a first resistor, a second resistor, and a third resistor. The first resistor, the second resistor, and the third resistor are connected in series between the IN pin and ground. The output terminal of the voltage divider circuit is located between the first resistor and the second resistor, and the PG pin is connected between the second resistor and the third resistor.

[0073] When the PG pin is in a high-impedance state, the first, second, and third resistors divide the input voltage, causing the voltage divider circuit to output a first voltage divider signal. When the PG pin is in a low-impedance state, the first and second resistors divide the input voltage, causing the voltage divider circuit to output a second voltage divider signal.

[0074] The first resistor, the second resistor, and the third resistor satisfy the following relationship:

[0075]

[0076]

[0077] Where R1 represents the first resistor, R2 represents the second resistor, R3 represents the third resistor, and U th U represents the threshold voltage of the enable pin. H U represents the first voltage threshold. L This indicates the second voltage threshold.

[0078] In this embodiment of the application, when the power chip changes from a closed state to an open output state, the voltage V at the input terminal is... in It should be no less than the activation threshold U H ,Right now:

[0079] V in ≥12V

[0080] When the input voltage rises to the turn-on threshold U H At that time, R1, R2, and R3 satisfy the following relationship:

[0081]

[0082] When the power chip switches from the on state to the off state, the input voltage V in It should not exceed the closing threshold U. H ,Right now:

[0083] V in ≤4.8V

[0084] When the voltage at the input terminal decreases to the shutdown threshold U L At that time, R1, R2, and R3 satisfy the following relationship:

[0085]

[0086] In summary, we obtain the following formula:

[0087] R1≥9R2

[0088] R1≤3R2+3R3

[0089] Therefore, when designing a hysteresis voltage divider circuit, R1, R2, and R3 need to meet the above conditions.

[0090] Input voltage V of the power supply chip in With output voltage V out The correspondence is as follows Figure 2 As shown, the hysteresis function is implemented. The following section combines... Figure 6 and Figure 2 The working process of the embodiments of this application will be described by way of example, and the specific working process is as follows:

[0091] Scenario 1: Voltage output start-up process

[0092] Step 1: Input voltage V in The range of variation can gradually increase from 0V to 22V. At V in Before the voltage is increased to 1.5V, the internal circuitry logic of the chip cannot be established, and the PG pin is in a high-impedance state. At V... in Above 1.5V to the voltage turn-on threshold U H Before (12V), the internal logic circuit of the chip starts to work, but the voltage of the EN pin is less than the threshold voltage of 1.2V, and the voltage of the output pin is 0. At this time, the PG pin is pulled low, that is, in a low-impedance state; the voltage of the EN pin is obtained by voltage division by resistors R1 and R2, that is, in the second voltage division relationship.

[0093] Step 2: When the input voltage V in Increase to the activation threshold U H At (12V), the voltage at the EN pin is 1.2V, and thereafter V in If the voltage continues to increase, the voltage at the EN pin will exceed the threshold voltage of 1.2V. The DC power management chip will then enable output, displaying the voltage V at the SW pin. outThe voltage changes from 0V to 3.3V, then the PG pin becomes high-impedance. The EN pin voltage is obtained by a voltage divider formed by resistors R1, R2, and R3, i.e., it is in the first voltage divider relationship. Therefore, the EN pin voltage will rise momentarily (without affecting the operating state of the power supply chip), and then V... in Continue increasing to 22V, the output voltage remains at 3.3V, the PG pin remains in a high-impedance state, and the EN pin remains 1.2V above the threshold voltage.

[0094] The second scenario: voltage output shutdown process

[0095] Step 1: Input voltage V in Gradually decrease from 22V, when V in Reduce to the shutdown threshold U L Before (4.8V), since the voltage of the PG pin is in a high-impedance state, the voltage of the EN pin is obtained by voltage division by resistors R1, R2, and R3. The voltage of the EN pin gradually decreases, but it is always greater than the threshold value of 1.2V.

[0096] Step 2: When V in Reduce to U L At (4.8V), the EN pin decreases to the threshold voltage of 1.2V, after which V in If the voltage at the EN pin continues to decrease, it will fall below the threshold voltage of 1.2V, causing the DC power management chip to shut down and the output voltage V. out The voltage changes from 3.3V to 0V. At this point, the PG pin will be pulled low, entering a low-impedance state. The EN pin voltage is obtained by the voltage divider between resistors R1 and R2, changing to a second voltage divider relationship. Therefore, the EN pin voltage will momentarily drop (this has no impact on the power supply chip's operating state). Afterwards, V... in As the voltage continues to decrease to 0V, the output voltage remains at 0V, the PG pin remains pulled low, and the EN pin remains below the threshold voltage of 1.2V.

[0097] This embodiment adds a resistor to the circuit and implements hysteresis by utilizing the two states of the PG pin and a voltage divider circuit. This significantly reduces circuit complexity, improves circuit stability, reduces susceptibility to external interference, and offers substantial advantages in terms of accuracy and stability.

[0098] Figure 7 This is a schematic structural diagram of an electronic device provided in an embodiment of this application. See also... Figure 7 The electronic device includes a load device 710 and such as Figure 4 , Figure 6 The power supply system 720 described in any one of the above is used to supply power to the load device 710.

[0099] When the input voltage of the power supply system 720 is greater than or equal to the first voltage threshold, the voltage divider circuit outputs the first voltage divider signal to the power supply chip. For example, the power supply chip can be... Figure 1 The DC power management chip shown controls the power chip to provide an output voltage to the load device 710. When the input voltage is less than a second voltage threshold, the voltage divider circuit outputs a second voltage divider signal to the power chip to control the power chip to stop providing the output voltage to the load device 710, wherein the first voltage threshold is less than the second voltage threshold.

[0100] The input voltage of the power supply system 720 may include a hysteresis voltage range, which is located between a first voltage threshold and a second voltage threshold. The power supply chip may include a first pin connected to a voltage divider circuit. When the voltage divider circuit outputs the first voltage divider signal, the first pin is in a high-impedance state; when the voltage divider circuit outputs the second voltage divider signal, the first pin is in a low-impedance state.

[0101] The above text combined Figures 1 to 7 The system embodiments of this application are described in detail below, in conjunction with... Figures 8 to 9 This application describes in detail the embodiments of the control method. It should be understood that the description of the method embodiments corresponds to the description of the system embodiments; therefore, any parts not described in detail can be referred to the preceding system embodiments.

[0102] Figure 8 This is a schematic flowchart of a method for controlling a power supply system provided in an embodiment of this application. Figure 8 The method can be applied to the power supply system mentioned in any of the preceding embodiments. Figure 8 The method includes steps S810, S820a, and S820b. These steps are described in detail below.

[0103] In step S810, the input voltage of the power supply system is determined.

[0104] In step S820a, when the input voltage of the power supply system is greater than or equal to the first voltage threshold, the first voltage divider signal is output to the power chip using the voltage divider circuit to control the power chip to provide output voltage.

[0105] In step S820b, when the input voltage of the power supply system is less than the second voltage threshold, the voltage divider circuit outputs a second voltage divider signal to the power chip to control the power chip to stop providing output voltage.

[0106] Optionally, the input voltage of the power supply system has a hysteresis voltage range defined by a first voltage threshold and a second voltage threshold. The power chip includes a first pin, which is connected to a voltage divider circuit. The first pin has a high-resistance state and a low-resistance state. When the first pin is in the high-resistance state, the voltage divider circuit outputs a first voltage divider signal to the power chip; when the first pin is in the low-resistance state, the voltage divider circuit outputs a second voltage divider signal to the power chip.

[0107] Optionally, in some embodiments, the output terminal of the voltage divider circuit is connected to the enable pin of the power chip to provide a first voltage divider signal or a second voltage divider signal to the enable pin of the power chip; when the voltage of the enable pin is greater than or equal to the threshold voltage of the enable pin, the first pin is in a high-impedance state, and when the voltage of the enable pin of the power chip is less than the threshold voltage of the enable pin, the first pin is in a low-impedance state.

[0108] Optionally, in some embodiments, the input voltage is within a first voltage range, which includes a start voltage and a stop voltage. Figure 8 The method may further include: when the input voltage increases from the starting voltage to the first voltage threshold, using a voltage divider circuit to control the voltage of the enable pin of the power chip to be less than the threshold voltage of the enable pin; when the input voltage decreases from the termination voltage to the second voltage threshold, using a voltage divider circuit to control the voltage of the enable pin of the power chip to be greater than or equal to the threshold voltage.

[0109] Optionally, in some embodiments, the power chip has a voltage input pin for receiving the input voltage. The voltage divider circuit includes a first resistor, a second resistor, and a third resistor, which are connected in series between the voltage input pin and ground. The output of the voltage divider circuit is located between the first resistor and the second resistor, and the first pin is connected between the second resistor and the third resistor. When the first pin is in a high-impedance state, the first resistor, the second resistor, and the third resistor divide the input voltage, so that the output of the voltage divider circuit outputs a first voltage divider signal. When the first pin is in a low-impedance state, the first resistor and the second resistor divide the input voltage, so that the output of the voltage divider circuit outputs a second voltage divider signal.

[0110] Optionally, in some embodiments, the first resistor, the second resistor, and the third resistor satisfy the following formula:

[0111]

[0112]

[0113] Where R1 represents the first resistor, R2 represents the second resistor, R3 represents the third resistor, and U th U represents the threshold voltage of the enable pin. HU represents the first voltage threshold. L This indicates the second voltage threshold.

[0114] Optionally, in some embodiments, the first pin is the PG pin of the power chip.

[0115] Figure 9 yes Figure 8 The diagram illustrates a possible implementation of the method shown. Figure 9 The method is based on a DC power management chip, and the working process includes a power-on process and a power-off process. Figure 9 The method may include steps S910 and S970, which are described in detail below.

[0116] Output activation process:

[0117] In step S910, before power-on, the power chip is in the off state and the PG pin is in the low state. The second voltage divider relationship, i.e. the resistance relationship between R1 and R2, is used to calculate the output voltage of the voltage divider circuit, i.e., the voltage of the enable terminal.

[0118] In step S920, it is determined whether the voltage at the enable terminal is higher than or equal to the threshold value of 1.2V. If the voltage at the enable terminal is higher than or equal to the threshold value of 1.2V, that is, the input terminal voltage is higher than or equal to the voltage turn-on threshold value of 12V, then proceed to step S930. If the voltage at the enable terminal is lower than the threshold value of 1.2V, that is, the input terminal voltage is lower than the voltage turn-on threshold value of 12V, then proceed to step S940.

[0119] In step S930, the power chip turns on the output, and the normal output voltage is 3.3V. The PG pin switches to a high-impedance state (or pull-high state). Proceed to step S950.

[0120] In step S940, the power chip remains off, with no output voltage at the output terminal, and the PG pin remains in a low-impedance state, i.e., pulled low. Proceed to step S910 to detect and calculate the voltage at the enable terminal.

[0121] Output shutdown process:

[0122] In step S950, the output of the power chip is in the on state. The first voltage divider relationship, that is, the resistance relationship of R1, R2 and R3, is used to calculate the output voltage of the voltage divider circuit, that is, to calculate the voltage of the enable terminal.

[0123] In step S960, it is determined whether the voltage at the enable terminal is higher than or equal to the threshold value of 1.2V. If the voltage at the enable terminal is higher than or equal to the threshold value of 1.2V, that is, the input terminal voltage is higher than or equal to the voltage shutdown threshold value of 4.8V, proceed to step S970. If the voltage at the enable terminal is lower than the threshold value of 1.2V, that is, the input terminal voltage is lower than the voltage shutdown threshold value of 4.8V, proceed to step S940, that is, the power chip turns off.

[0124] In step S970, the power chip is in the ON state, with a normal output voltage of 3.3V. The PG transistor is still in a high-impedance state or in a pulled-high state. Proceed to step S950 to detect and calculate the voltage at the enable terminal.

[0125] It should be understood that in the various embodiments of this application, "first," "second," etc., are used to distinguish different objects, rather than to describe a specific order. The order of the above-mentioned process numbers does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0126] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0127] In the embodiments provided in this application, it should be understood that when a part is referred to as "connected" or "linked" to another part, it means that the part can be "directly connected" and also "electrically connected," with another element involved. Furthermore, the term "connected" also means that the parts are "physically connected" and "wirelessly connected." Additionally, when a part is referred to as "containing" an element, unless otherwise stated, it means that the part may include, but does not exclude, the other element.

[0128] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0129] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0130] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A power supply system, characterized in that, include: A power chip is used to receive an input voltage and convert the input voltage into the output voltage of the power chip. A voltage divider circuit is used to output a first voltage divider signal to the power chip when the input voltage is greater than or equal to a first voltage threshold, so as to control the power chip to provide the output voltage; and to output a second voltage divider signal to the power chip when the input voltage is less than a second voltage threshold, so as to control the power chip to stop providing the output voltage, wherein the first voltage threshold is greater than the second voltage threshold. The power chip includes a first pin, which is connected to the voltage divider circuit. When the voltage divider circuit outputs the first voltage divider signal, the first pin is in a high-impedance state; when the voltage divider circuit outputs the second voltage divider signal, the first pin is in a low-impedance state.

2. The power supply system according to claim 1, characterized in that, The output terminal of the voltage divider circuit is connected to the enable pin of the power chip to provide the first voltage divider signal or the second voltage divider signal to the enable pin of the power chip. When the voltage of the enable pin is greater than or equal to the threshold voltage of the enable pin, the first pin is in the high-resistance state; when the voltage of the enable pin of the power chip is less than the threshold voltage of the enable pin, the first pin is in the low-resistance state.

3. The power supply system according to claim 2, characterized in that, The input voltage is within a first voltage range, which includes a starting voltage and a termination voltage. The voltage divider circuit is also used to control the voltage of the enable pin of the power chip to be less than the threshold voltage when the input voltage increases from the starting voltage to the first voltage threshold, and to control the voltage of the enable pin of the power chip to be greater than or equal to the threshold voltage when the input voltage decreases from the ending voltage to the second voltage threshold.

4. The power supply system according to claim 2, characterized in that, The power chip has a voltage input pin for receiving the input voltage. The voltage divider circuit includes a first resistor, a second resistor, and a third resistor. The first resistor, the second resistor, and the third resistor are connected in series between the voltage input pin and ground. The output terminal of the voltage divider circuit is located between the first resistor and the second resistor. The first pin is connected between the second resistor and the third resistor.

5. The power supply system according to claim 4, characterized in that, The first resistor, the second resistor, and the third resistor satisfy the following formula: ； as well as ； Wherein, R1 represents the first resistor, R2 represents the second resistor, R3 represents the third resistor, and U th U represents the threshold voltage of the enable pin. H U represents the first voltage threshold. L This indicates the second voltage threshold.

6. The power supply system according to any one of claims 1-5, characterized in that, The first pin is the PG pin of the power chip.

7. An electronic device, characterized in that, include: Load devices; A power supply system, the power supply system comprising: A power chip is used to receive an input voltage and convert the input voltage into the output voltage of the power chip. A voltage divider circuit is configured to: output a first voltage divider signal to the power supply chip when the input voltage is greater than or equal to a first voltage threshold, thereby controlling the power supply chip to provide the output voltage to the load device; and output a second voltage divider signal to the power supply chip when the input voltage is less than a second voltage threshold, thereby controlling the power supply chip to stop providing the output voltage to the load device. The first voltage threshold is greater than the second voltage threshold. The power supply chip includes a first pin connected to the voltage divider circuit. When the voltage divider circuit outputs the first voltage divider signal, the first pin is in a high-impedance state; when the voltage divider circuit outputs the second voltage divider signal, the first pin is in a low-impedance state.

8. A method for controlling a power supply system, characterized in that, include: When the input voltage of the power system is greater than or equal to the first voltage threshold, the voltage divider circuit outputs the first voltage divider signal to the power chip to control the power chip to provide output voltage. When the input voltage is less than the second voltage threshold, the voltage divider circuit outputs a second voltage divider signal to the power chip to control the power chip to stop providing the output voltage. Wherein, the first voltage threshold is greater than the second voltage threshold; The power chip includes a first pin, which is connected to the voltage divider circuit. When the voltage divider circuit outputs the first voltage divider signal, the first pin is in a high-impedance state; when the voltage divider circuit outputs the second voltage divider signal, the first pin is in a low-impedance state.

9. The method according to claim 8, characterized in that, The output terminal of the voltage divider circuit is connected to the enable pin of the power chip to provide the first voltage divider signal or the second voltage divider signal to the enable pin of the power chip. When the voltage of the enable pin is greater than or equal to the threshold voltage of the enable pin, the first pin is in the high-resistance state; when the voltage of the enable pin of the power chip is less than the threshold voltage of the enable pin, the first pin is in the low-resistance state.

10. The method according to claim 9, characterized in that, The input voltage is within a first voltage range, which includes a start voltage and a stop voltage. The method further includes: As the input voltage increases from the starting voltage to the first voltage threshold, the voltage of the enable pin of the power chip is controlled to be less than the threshold voltage of the enable pin using the voltage divider circuit. As the input voltage decreases from the termination voltage to the second voltage threshold, the voltage of the enable pin of the power chip is controlled by the voltage divider circuit to be greater than or equal to the threshold voltage.

11. The method according to claim 9, characterized in that, The power chip has a voltage input pin for receiving the input voltage. The voltage divider circuit includes a first resistor, a second resistor, and a third resistor. The first resistor, the second resistor, and the third resistor are connected in series between the voltage input pin and ground. The output terminal of the voltage divider circuit is located between the first resistor and the second resistor. The first pin is connected between the second resistor and the third resistor.

12. The method according to claim 11, characterized in that, The first resistor, the second resistor, and the third resistor satisfy the following formula: ;as well as ； Wherein, R1 represents the first resistor, R2 represents the second resistor, R3 represents the third resistor, and U th U represents the threshold voltage of the enable pin. H U represents the first voltage threshold. L This indicates the second voltage threshold.

13. The method according to any one of claims 8-12, characterized in that, The first pin is the PG pin of the power chip.

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