Output voltage control method and system

Abstract

The embodiment of the present application provides an output voltage control method and system, which is applied to a negative power supply control circuit, the negative power supply control circuit comprises an internal oscillator, an amplifier, a comparator and a pulse width modulation control circuit, the negative power supply control circuit is connected with a negative power supply conversion circuit, and the method comprises the following steps: generating a sawtooth wave through the internal oscillator; amplifying a feedback voltage input by the negative power supply conversion circuit based on a preset reference voltage through the amplifier; comparing the amplified feedback voltage with the sawtooth wave through the comparator to generate a pulse width modulation signal; and inputting the pulse width modulation signal into the negative power supply conversion circuit through the pulse width modulation control circuit to control the output voltage of the negative power supply conversion circuit. The embodiment of the present application can complete the output control of the output voltage of the negative power supply conversion circuit by using few external devices, and reduces the cost of products.

Description

Technical Field

[0001] This invention relates to the field of power supply circuit technology, and in particular to an output voltage control method and an output voltage control system. Background Technology

[0002] With the advancement of science and technology, life has become increasingly technologically advanced. Many products are generally powered by DC power supplies in order to achieve miniaturization, such as power adapters, lithium batteries, and nickel-metal hydride batteries. However, some devices, such as operational amplifiers, often use negative power supplies to achieve higher dynamic range, higher signal-to-noise ratio, and better performance.

[0003] Existing negative power conversion solutions often employ charge pumps or transformers. However, these solutions suffer from limitations such as limited circuit functionality, low load capacity, large PCB (Printed Circuit Board) footprint, or non-adjustable output voltage, which increase the product's circuit cost. Summary of the Invention

[0004] This invention provides an output voltage control method to solve the problem of high circuit cost in existing products.

[0005] Accordingly, embodiments of the present invention also provide an output voltage control system to ensure the implementation and application of the above method.

[0006] To address the aforementioned problems, this invention discloses an output voltage control method applied to a negative power supply control circuit. The negative power supply control circuit includes an internal oscillator, an amplifier, a comparator, and a pulse width modulation control circuit. The negative power supply control circuit is connected to a negative power supply conversion circuit. The method includes:

[0007] A sawtooth wave is generated by the internal oscillator.

[0008] The amplifier amplifies the feedback voltage input to the negative power supply conversion circuit based on a preset reference voltage.

[0009] The amplified feedback voltage is compared with the sawtooth wave by the comparator to generate a pulse width modulation signal;

[0010] The pulse width modulation signal is input to the negative power conversion circuit through the pulse width modulation control circuit to control the output voltage of the negative power conversion circuit.

[0011] Optionally, the negative power supply conversion circuit includes an input voltage, an output voltage, a transistor, an inductor, a diode, a first resistor, a second resistor, a first capacitor, and a second capacitor; the input voltage is connected to the first capacitor, the first capacitor is grounded, the input voltage is connected to the source of the transistor, the gate of the transistor is connected to the output terminal of the pulse width modulation control circuit of the negative power supply control circuit, the drain of the transistor is connected to the negative terminals of the inductor and the diode, the inductor is grounded, the anode of the diode is connected to the second capacitor, the output voltage, and the first resistor, the second capacitor is grounded, the first resistor is connected to the second resistor, the second resistor is connected to the input voltage, and the first resistor is connected to the amplifier of the negative power supply control circuit.

[0012] Optionally, when the transistor is controlled to close and conduct by the pulse width modulation signal, the first capacitor charges the inductor, the diode is turned off, and the output voltage is discharged through the second capacitor to supply power to the load.

[0013] Optionally, when the transistor is turned off by the pulse width modulation signal, the input voltage charges the first capacitor, the diode is turned on, and the inductor supplies power to the second capacitor and the load through the diode.

[0014] Optionally, when the magnitude of the input voltage is determined, the magnitude of the output voltage changes accordingly as the resistance values ​​of the first resistor and the second resistor change.

[0015] Optionally, when the first resistor and the second resistor are determined, the magnitude of the output voltage changes accordingly as the magnitude of the input voltage changes.

[0016] Optionally, the first resistor and the second resistor are adjustable resistors.

[0017] Optionally, the input voltage is an adjustable input voltage.

[0018] Optionally, the transistor is a metal-oxide-semiconductor field-effect transistor.

[0019] This invention also discloses an output voltage control system, which includes a negative power supply control circuit and a negative power supply conversion circuit connected together. The negative power supply control circuit includes an internal oscillator, an amplifier, a comparator, and a pulse width modulation control circuit, wherein:

[0020] The negative power supply control circuit is used to generate a sawtooth wave through the internal oscillator; amplify the feedback voltage input to the negative power supply conversion circuit based on a preset reference voltage through the amplifier; compare the amplified feedback voltage with the sawtooth wave through the comparator to generate a pulse width modulation signal; and input the pulse width modulation signal to the negative power supply conversion circuit through the pulse width modulation control circuit to control the output voltage of the negative power supply conversion circuit.

[0021] Optionally, the negative power supply conversion circuit includes an input voltage, an output voltage, a transistor, an inductor, a diode, a first resistor, a second resistor, a first capacitor, and a second capacitor; the input voltage is connected to the first capacitor, the first capacitor is grounded, the input voltage is connected to the source of the transistor, the gate of the transistor is connected to the output terminal of the pulse width modulation control circuit of the negative power supply control circuit, the drain of the transistor is connected to the negative terminals of the inductor and the diode, the inductor is grounded, the anode of the diode is connected to the second capacitor, the output voltage, and the first resistor, the second capacitor is grounded, the first resistor is connected to the second resistor, the second resistor is connected to the input voltage, and the first resistor is connected to the amplifier of the negative power supply control circuit.

[0022] Optionally, when the transistor is controlled to close and conduct by the pulse width modulation signal, the first capacitor charges the inductor, the diode is turned off, and the output voltage is discharged through the second capacitor to supply power to the load.

[0023] Optionally, when the transistor is turned off by the pulse width modulation signal, the input voltage charges the first capacitor, the diode is turned on, and the inductor supplies power to the second capacitor and the load through the diode.

[0024] Optionally, when the magnitude of the input voltage is determined, the magnitude of the output voltage changes accordingly as the resistance values ​​of the first resistor and the second resistor change.

[0025] Optionally, when the first resistor and the second resistor are determined, the magnitude of the output voltage changes accordingly as the magnitude of the input voltage changes.

[0026] Optionally, the first resistor and the second resistor are adjustable resistors.

[0027] Optionally, the input voltage is an adjustable input voltage.

[0028] Optionally, the transistor is a metal-oxide-semiconductor field-effect transistor.

[0029] The embodiments of the present invention have the following advantages:

[0030] In this embodiment of the invention, the negative power supply control circuit includes an internal oscillator, an amplifier, a comparator, and a pulse width modulation (PWM) control circuit. The negative power supply control circuit is connected to the negative power supply conversion circuit. The negative power supply control circuit generates a sawtooth wave through its internal oscillation. The amplifier amplifies the feedback voltage input to the negative power supply conversion circuit based on a preset reference voltage. The comparator then compares the amplified feedback voltage with the sawtooth wave to generate a PWM signal. Finally, the PWM control circuit inputs the PWM signal to the negative power supply conversion circuit to control its output voltage. This embodiment of the invention controls the output voltage of the negative power supply conversion circuit using a negative power supply control circuit, requiring very few external components to control the negative power supply (output voltage) output of the negative power supply conversion circuit, thus reducing product cost. Attached Figure Description

[0031] Figure 1 This is a flowchart illustrating the steps of an output voltage control method provided in an embodiment of the present invention;

[0032] Figure 2 A waveform diagram of a sawtooth wave provided in an embodiment of the present invention;

[0033] Figure 3 This is a waveform diagram of a pulse width modulation signal provided in an embodiment of the present invention;

[0034] Figure 4 This is a flowchart of the output voltage control of a negative power supply conversion circuit provided in an embodiment of the present invention;

[0035] Figure 5 This is a system block diagram of a negative power supply control system provided in an embodiment of the present invention;

[0036] Figure 6 This is a block diagram of a charge pump negative power supply conversion circuit provided in an embodiment of the present invention;

[0037] Figure 7 This is a block diagram of a transformer-based negative power supply conversion circuit provided in an embodiment of the present invention;

[0038] Figure 8 This is a structural block diagram of an output voltage control system provided in an embodiment of the present invention. Detailed Implementation

[0039] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0040] Reference Figure 1 The diagram illustrates a flowchart of an output voltage control method according to an embodiment of the present invention. The method may specifically include the following steps:

[0041] Step 101: Generate a sawtooth wave using the internal oscillator.

[0042] In this embodiment of the invention, the negative power supply control system may include a negative power supply control circuit and a negative power supply conversion circuit. The negative power supply control circuit may include an internal oscillator, an amplifier, a comparator, and a pulse width modulation control circuit. The negative power supply control circuit is connected to the negative power supply conversion circuit. Specifically, the internal oscillator is an OSC oscillator. The internal oscillator mainly provides a clock signal for the operation of the negative power supply control system and is one of the important parts of the operation of the negative power supply control system. The clock signal generated by the internal oscillator, in conjunction with a related sawtooth wave circuit, can generate a sawtooth wave. For example, refer to... Figure 2 This is a waveform diagram of a sawtooth wave provided in an embodiment of the present invention.

[0043] Step 102: The feedback voltage input to the negative power supply conversion circuit is amplified by the amplifier based on a preset reference voltage.

[0044] In this embodiment of the invention, the amplifier includes an error level amplifier, which amplifies the feedback voltage fed back from the negative power supply conversion circuit based on a preset reference voltage (Vref, which can be 0.6V (volts)) to avoid the negative power supply control system error deviation caused by the error value being too small.

[0045] Step 103: The amplified feedback voltage is compared with the sawtooth wave by the comparator to generate a pulse width modulation signal.

[0046] In this embodiment of the invention, the comparator can compare the amplified feedback voltage with a sawtooth wave to generate a pulse width modulation (PWM) signal. For example, refer to... Figure 3 This is a waveform diagram of a pulse width modulation signal provided in an embodiment of the present invention. The pulse width modulation signal is a square wave.

[0047] Step 104: Input the pulse width modulation signal to the negative power conversion circuit through the pulse width modulation control circuit to control the output voltage of the negative power conversion circuit.

[0048] In this embodiment of the invention, the pulse width modulation control circuit can also be called a PWM control circuit. The pulse width modulation control circuit controls whether the pulse width modulation signal is switched on or off. If the pulse width modulation signal is normal, the pulse width modulation control signal is turned on and the pulse width modulation signal is output to the negative power conversion circuit to control the output voltage of the negative power conversion circuit. If the pulse width modulation signal is abnormal, the pulse width modulation control signal is turned off and the pulse width modulation signal output to the negative power conversion circuit is turned off.

[0049] Reference Figure 4This is a flowchart illustrating the output voltage control of a negative power conversion circuit according to an embodiment of the present invention. The negative power control system in this embodiment mainly consists of four parts: an internal oscillator, an error level amplifier, a comparator, and a PWM control circuit. This embodiment requires only a few external components to control the output power of the negative power conversion circuit, featuring high integration and a compact structure. The specific flow is shown below:

[0050] 1. The internal oscillator mainly provides the clock signal for the system operation and is an important part of the system operation. The clock signal, together with the relevant sawtooth wave circuit, generates a sawtooth wave.

[0051] 2. The amplifier amplifies the voltage fed back from the system at a preset reference voltage; otherwise, if the error value is too small, it will lead to system error deviation.

[0052] 3. The comparator compares the amplified signal with the sawtooth wave to generate a pulse width modulation square wave, i.e., a PWM signal.

[0053] 4. The PWM control circuit controls whether the PWM signal is switched on or off. If the PWM signal is normal, the PWM control signal is turned on and the PWM signal is output to the negative power conversion circuit. If the PWM signal is abnormal, the PWM control signal is turned off and the PWM signal output to the negative power conversion circuit is turned off.

[0054] In this embodiment of the invention, the negative power supply control circuit includes an internal oscillator, an amplifier, a comparator, and a pulse width modulation (PWM) control circuit. The negative power supply control circuit is connected to the negative power supply conversion circuit. The negative power supply control circuit generates a sawtooth wave through its internal oscillation. The amplifier amplifies the feedback voltage input to the negative power supply conversion circuit based on a preset reference voltage. The comparator then compares the amplified feedback voltage with the sawtooth wave to generate a PWM signal. Finally, the PWM control circuit inputs the PWM signal to the negative power supply conversion circuit to control its output voltage. This embodiment of the invention controls the output voltage of the negative power supply conversion circuit using a negative power supply control circuit, requiring very few external components to control the negative power supply (output voltage) output of the negative power supply conversion circuit, thus reducing product cost.

[0055] In one embodiment of the present invention, reference is made to... Figure 5This is a system block diagram of a negative power supply control system provided in an embodiment of the present invention. The negative power supply control system may include a negative power supply control circuit and a negative power supply conversion circuit. The negative power supply control circuit includes an internal oscillator (OSC), an amplifier, a comparator, and a PWM control circuit. The PWM control circuit can send a PWM signal to the negative power supply conversion circuit to control the output voltage of the negative power supply conversion circuit. The negative power supply conversion circuit may include an input voltage Vin, an output voltage Vout, a transistor Q1, an inductor L1, a diode D1, a first resistor R1, a second resistor R2, a first capacitor C1, and a second capacitor C2. Specifically, the input voltage Vin is connected to the first capacitor C1, which is grounded (GND). The input voltage Vin is connected to the source (S) of the transistor Q1. The gate (G) of the transistor Q1 is connected to the output terminal of the pulse width modulation control circuit of the negative power supply control circuit. The drain (D) of the transistor Q1 is connected to the negative terminals of the inductor L1 and the diode D1. The inductor L1 is grounded (GND). The positive terminal of the diode D1 is connected to the second capacitor C2, the output voltage Vout, and the first resistor R1. The second capacitor C2 is grounded (GND). The first resistor R1 is connected to the second resistor R2. The second resistor R2 is connected to the input voltage Vin. The first resistor R1 is connected to the amplifier of the negative power supply control circuit.

[0056] As an optional example of the present invention, transistor Q1 may be a metal-oxide-semiconductor field-effect transistor (MOSFET). Furthermore, the first resistor R1 and the second resistor R2 are adjustable resistors with adjustable resistance values, and the input voltage Vin is an adjustable input voltage.

[0057] In one embodiment of the present invention, when the transistor Q1 is closed and turned on by the pulse width modulation signal, the first capacitor C1 charges the inductor L1, the diode D is turned off, and the output voltage Vout is discharged through the second capacitor C2 to supply power to the load.

[0058] In this embodiment of the invention, the negative power supply control system operates normally. When transistor Q1 is turned on by the PWM signal, the current flows from input voltage Vin -> transistor Q1 -> inductor L1 -> ground GND -> first capacitor C1 -> input voltage Vin. At this time, the input voltage Vin is directly connected to both ends of inductor L1, directly charging inductor L1. The current in inductor L1 gradually increases, and the inductance di / dt of inductor L1 is very large. This process is mainly powered by input capacitor C1, which is charged when the input voltage Vin is turned off by the PWM signal. Since transistor Q1 is turned on, it is equivalent to transistor Q1 being in a short-circuit state. Therefore, the voltages across diode D1 are the input voltage Vin and the output voltage Vout, respectively. Since the output voltage Vout is negative, diode D1 is reverse cutoff, and the output voltage Vout supplies power (energy) to the load by discharging through the second capacitor C2.

[0059] In one embodiment of the present invention, when the transistor Q1 is turned off by the pulse width modulation signal, the input voltage Vin charges the first capacitor C1, the diode D is turned on, and the inductor L1 supplies power to the load through the second capacitor C2 and the diode D1.

[0060] In this embodiment of the invention, the negative power supply control system operates normally. When transistor Q1 is turned off via a PWM signal, the input voltage Vin charges the first input capacitor C1. Since the inductor current cannot change abruptly, inductor L1 provides energy to the load through the second capacitor C2 and freewheeling diode D1. The current flow is from second capacitor C2 -> diode D1 -> inductor L1 -> second capacitor C2.

[0061] It should be noted that since the output voltage Vout is converted from the input power supply Vin, the voltage across the transistor and diode D1 is Vin + Vout. Therefore, the withstand voltage should be considered when selecting components.

[0062] In one embodiment of the present invention, when the magnitude of the input voltage Vin is determined, the resistance values ​​of the first resistor R1 and the second resistor R2 change, and the magnitude of the output voltage Vout changes accordingly; when the first resistor R1 and the second resistor R2 are determined, the magnitude of the input voltage Vin changes, and the magnitude of the output voltage Vout changes accordingly.

[0063] refer to Figure 5 The voltage difference across the second resistor R2 is (Vfb - Vin), therefore the current flowing through the second resistor R2 is (Vfb - Vin) / R2. Figure 5It can be seen that the current flowing through the first resistor R1 is also (Vfb-Vin) / R2, so the voltage across (R1+R2) is current * resistance, i.e. Vout-Vin is the voltage across (R1+R2), that is:

[0064]

[0065]

[0066] Here, Vfb is the feedback voltage, which needs to be set in advance; it is the amplifier voltage plus the reference voltage Vref. According to Equation 1, with a fixed input voltage Vin, changing the values ​​of the first resistor R1 and the second resistor R2 can change the output voltage Vout. Furthermore, according to Equation 1, the output voltage Vout is also related to the input voltage Vin. Therefore, if the values ​​of the first resistor R1 and the second resistor R2 are fixed, changing the input voltage Vin can also change the output voltage Vout.

[0067] In summary, the embodiments of the present invention can achieve the purpose of adjusting the output voltage Vout of the negative power supply by changing the resistance value of the first resistor R1 or the second resistor R2, or by changing the magnitude of the input voltage Vin, without increasing costs. The implementation method is simple and easy to implement, and has a wide range of applications.

[0068] In relevant technical solutions, there are many approaches for the output voltage Vout (negative power supply). For example, Solution 1: Refer to... Figure 6 The first option is a block diagram of a charge pump negative power supply conversion circuit. The negative power supply can be generated by the charge pump. This solution mainly suffers from a single output voltage and poor load-carrying capacity. Option 2: The negative power supply can be generated by a transformer, as shown in the diagram. Figure 7 Scheme 2 is a transformer-based negative power supply conversion circuit block diagram. It requires an AC power supply, a T1 transformer, rectifier devices, and electrolytic capacitors. After outputting the negative power supply, if a smaller power ripple is required, it is usually achieved by adding an external negative power supply LDO (Low Drop-Out, voltage regulator). It can be seen that Scheme 2 uses more components, has low efficiency, a larger transformer size, occupies more PCB area, has high cost, and has limited space requirements.

[0069] In practical applications, operational amplifiers in audio systems (home audio, car audio) often use both positive and negative power supplies. The negative power supply generated by Scheme 1 typically uses an input voltage of only 5.5V, has a load capacity of only tens of mA, and has too little output power, limiting its application range. The negative power supply generated by Scheme 2 can be produced by a transformer, but transformers are relatively large, occupy a large PCB area, and have limited space requirements.

[0070] This invention provides a method for adjusting the output voltage of a negative power supply, which can provide the corresponding output voltage (negative power supply) as needed without requiring additional voltage regulator circuitry, high-precision circuitry, or increased circuit costs. Specifically, this invention uses a PWM signal to control the output voltage. Thus, the negative power supply output voltage can be adjusted by changing different feedback resistor values ​​without increasing costs.

[0071] It should be noted that, for the sake of simplicity, the method embodiments are all described as a series of actions. However, those skilled in the art should understand that the embodiments of the present invention are not limited to the described order of actions, because according to the embodiments of the present invention, some steps can be performed in other orders or simultaneously. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions involved are not necessarily essential to the embodiments of the present invention.

[0072] Reference Figure 8 The diagram illustrates a structural block diagram of an output voltage control system provided by an embodiment of the present invention. The output voltage control system includes a negative power supply control circuit 801 and a negative power supply conversion circuit 802 connected together. The negative power supply control circuit 801 includes an internal oscillator, an amplifier, a comparator, and a pulse width modulation control circuit, wherein:

[0073] The negative power supply control circuit 802 is used to generate a sawtooth wave through the internal oscillator; amplify the feedback voltage input to the negative power supply conversion circuit based on a preset reference voltage through the amplifier; compare the amplified feedback voltage with the sawtooth wave through the comparator to generate a pulse width modulation signal; and input the pulse width modulation signal to the negative power supply conversion circuit through the pulse width modulation control circuit to control the output voltage of the negative power supply conversion circuit 802.

[0074] In one embodiment of the present invention, the negative power supply conversion circuit 802 may include an input voltage, an output voltage, a transistor, an inductor, a diode, a first resistor, a second resistor, a first capacitor, and a second capacitor; the input voltage is connected to the first capacitor, the first capacitor is grounded, the input voltage is connected to the source of the transistor, the gate of the transistor is connected to the output terminal of the pulse width modulation control circuit of the negative power supply control circuit, the drain of the transistor is connected to the negative terminals of the inductor and the diode, the inductor is grounded, the anode of the diode is connected to the second capacitor, the output voltage, and the first resistor, the second capacitor is grounded, the first resistor is connected to the second resistor, the second resistor is connected to the input voltage, and the first resistor is connected to the amplifier of the negative power supply control circuit.

[0075] In one embodiment of the present invention, when the transistor is controlled to close and conduct by the pulse width modulation signal, the first capacitor charges the inductor, the diode is turned off, and the output voltage is discharged through the second capacitor to supply power to the load.

[0076] In one embodiment of the present invention, when the transistor is turned off by the pulse width modulation signal, the input voltage charges the first capacitor, the diode is turned on, and the inductor supplies power to the second capacitor and the load through the diode.

[0077] In one embodiment of the present invention, when the magnitude of the input voltage is determined, the magnitude of the output voltage changes accordingly as the resistance values ​​of the first resistor and the second resistor change.

[0078] In one embodiment of the present invention, when the first resistor and the second resistor are determined, the magnitude of the input voltage changes and the magnitude of the output voltage changes accordingly.

[0079] In one embodiment of the present invention, the first resistor and the second resistor are adjustable resistors.

[0080] In one embodiment of the present invention, the input voltage is an adjustable input voltage.

[0081] In one embodiment of the present invention, the transistor is a metal-oxide-semiconductor field-effect transistor.

[0082] In this embodiment of the invention, the negative power supply control circuit includes an internal oscillator, an amplifier, a comparator, and a pulse width modulation (PWM) control circuit. The negative power supply control circuit is connected to the negative power supply conversion circuit. The negative power supply control circuit generates a sawtooth wave through its internal oscillation. The amplifier amplifies the feedback voltage input to the negative power supply conversion circuit based on a preset reference voltage. The comparator then compares the amplified feedback voltage with the sawtooth wave to generate a PWM signal. Finally, the PWM control circuit inputs the PWM signal to the negative power supply conversion circuit to control its output voltage. This embodiment of the invention controls the output voltage of the negative power supply conversion circuit using a negative power supply control circuit, requiring very few external components to control the negative power supply (output voltage) output of the negative power supply conversion circuit, thus reducing product cost.

[0083] As the system implementation is basically similar to the method implementation, it is described in a relatively simple way. For relevant details, please refer to the description of the method implementation.

[0084] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0085] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, apparatus, or computer program products. Therefore, embodiments of the present invention can take the form of entirely hardware embodiments, entirely software embodiments, or embodiments combining software and hardware aspects. Furthermore, embodiments of the present invention can take the form of computer program products implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, EEPROM, Flash, and eMMC, etc.) containing computer-usable program code.

[0086] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, terminal devices (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing terminal device to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing terminal device, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0087] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing terminal device to operate in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0088] These computer program instructions can also be loaded onto a computer or other programmable data processing terminal equipment, causing a series of operational steps to be performed on the computer or other programmable terminal equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable terminal equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0089] Although preferred embodiments of the present invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the embodiments of the present invention.

[0090] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or terminal device. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or terminal device that includes said element.

[0091] The above provides a detailed description of the output voltage control method and the output voltage control system provided by the present invention. Specific examples have been used to illustrate the principle and implementation of the present invention. The description of the above embodiments is only for the purpose of helping to understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation and application scope based on the idea of ​​the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. An output voltage control method, characterized in that, An application is made in a negative power supply control circuit, the negative power supply control circuit including an internal oscillator, an amplifier, a comparator, and a pulse width modulation control circuit, the negative power supply control circuit being connected to a negative power supply conversion circuit, the method comprising: A sawtooth wave is generated by the internal oscillator. The amplifier amplifies the feedback voltage input to the negative power supply conversion circuit based on a preset reference voltage. The amplified feedback voltage is compared with the sawtooth wave by the comparator to generate a pulse width modulation signal; The pulse width modulation signal is input to the negative power conversion circuit through the pulse width modulation control circuit to control the output voltage of the negative power conversion circuit. The negative power conversion circuit includes an input voltage, an output voltage, a transistor, an inductor, a diode, a first resistor, a second resistor, a first capacitor, and a second capacitor. The input voltage is connected to the first capacitor, which is grounded. The input voltage is connected to the source of the transistor. The gate of the transistor is connected to the output terminal of the pulse width modulation control circuit of the negative power control circuit. The drain of the transistor is connected to the negative terminals of the inductor and the diode. The inductor is grounded. The anode of the diode is connected to the second capacitor, the output voltage, and the first resistor. The second capacitor is grounded. The first resistor is connected to the second resistor. The second resistor is connected to the input voltage. The first resistor is connected to the amplifier of the negative power control circuit.

2. The method according to claim 1, characterized in that, When the transistor is turned on by the pulse width modulation signal, the first capacitor charges the inductor, the diode is turned off, and the output voltage is discharged through the second capacitor to supply power to the load.

3. The method according to claim 1, characterized in that, When the transistor is turned off by the pulse width modulation signal, the input voltage charges the first capacitor, the diode turns on, and the inductor supplies power to the second capacitor and the load through the diode.

4. The method according to claim 1, characterized in that, When the magnitude of the input voltage is determined, the magnitude of the output voltage changes accordingly as the resistance values ​​of the first resistor and the second resistor change.

5. The method according to claim 1, characterized in that, When the first resistor and the second resistor are determined, the magnitude of the output voltage changes accordingly as the magnitude of the input voltage changes.

6. The method according to claim 4, characterized in that, The first resistor and the second resistor are adjustable resistors.

7. The method according to claim 5, characterized in that, The input voltage is an adjustable input voltage.

8. The method according to claim 1, characterized in that, The transistor is a metal-oxide-semiconductor field-effect transistor.

9. An output voltage control system, characterized in that, The output voltage control system includes a negative power supply control circuit and a negative power supply conversion circuit connected together. The negative power supply control circuit includes an internal oscillator, an amplifier, a comparator, and a pulse width modulation control circuit, wherein: The negative power supply control circuit is used to generate a sawtooth wave through the internal oscillator; amplify the feedback voltage input to the negative power supply conversion circuit based on a preset reference voltage through the amplifier; compare the amplified feedback voltage with the sawtooth wave through the comparator to generate a pulse width modulation signal; and input the pulse width modulation signal to the negative power supply conversion circuit through the pulse width modulation control circuit to control the output voltage of the negative power supply conversion circuit. The negative power supply conversion circuit includes an input voltage, an output voltage, a transistor, an inductor, a diode, a first resistor, a second resistor, a first capacitor, and a second capacitor. The input voltage is connected to the first capacitor, which is grounded. The input voltage is connected to the source of the transistor. The gate of the transistor is connected to the output terminal of the pulse width modulation control circuit of the negative power supply control circuit. The drain of the transistor is connected to the negative terminals of the inductor and the diode, which is grounded. The anode of the diode is connected to the second capacitor, the output voltage, and the first resistor. The second capacitor is grounded. The first resistor is connected to the second resistor, which is connected to the input voltage. The first resistor is connected to the amplifier of the negative power supply control circuit.

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