Pump power supply control circuit for high-side driving

Abstract

The utility model relates to the technical field of power supply control, in particular to a pump power supply control circuit for high-side driving. The circuit comprises a pump power supply controller which is used for generating a driving control signal and adjusting the driving control signal according to an error signal; the driving module is used for receiving a driving control signal; the power conversion unit is configured to boost a direct current input voltage into a pump voltage under the control of the driving module according to the driving control signal; the feedback sampling circuit is used for sampling the pump voltage and generating an error signal; the isolation feedback device is used for transmitting the error signal to the pump power supply controller in a potential isolation mode; the pump power supply controller takes the cathode of the DC input power supply as the reference ground, and the pump voltage takes the anode of the DC input power supply as the reference standard. The scheme is suitable for high-side driving application, is a pump power supply control scheme which is novel in structure, stable in performance, flexible in control and controllable in cost, and has good popularization and application prospects.

Description

High-side drive pump power supply control circuit Technical Field

[0001] This utility model relates to the field of power control technology, and in particular to a power control circuit for a high-side drive pump. Background Technology

[0002] In power control systems, control or drive operations are often required at the positive terminal of the DC power supply; this is known as high-side control. High-side control is widely used in DC-DC converters, battery management systems, power bridge arm drives, and lossless rectification. However, because the high-side control device is floating relative to the negative terminal of the power supply, it is difficult for ordinary control circuits to drive it directly. Therefore, an additional pump power supply needs to be designed to raise the reference potential and provide the drive voltage for the high-side control device.

[0003] Traditional solutions often employ a charge pump structure, as shown in Figure 1. This involves alternately controlling multiple clock signals to charge and discharge the capacitor, achieving voltage multiplication or boosting to drive high-side devices. However, this type of circuit has the following drawbacks:

[0004] 1. Limited output capacity: Charge pumps rely on capacitor energy storage, which limits the output current and makes it difficult to provide stable high-power output;

[0005] 2. Complex control: A dedicated dual-phase clock controller is required to ensure mutual complementarity between the two phases, resulting in a complex control circuit.

[0006] 3. Difficulty in selecting components: High-side control usually requires the use of P-type components, which have limited options and high power consumption in high-voltage scenarios;

[0007] 4. Limited applicability: It is only applicable to light load and milliwatt-level applications, and cannot meet the actual needs of industrial-grade, high-voltage and high-current applications.

[0008] Therefore, there is an urgent need for a pump power supply control scheme that is simple in structure, has strong output capability, flexible in control and has a wide range of applications, in order to meet the extensive needs of modern power systems for high-side control. Summary of the Invention

[0009] The purpose of this invention is to provide a high-side drive pump power supply control circuit to address the shortcomings of existing technologies. It aims to achieve a stable pump voltage output under the positive reference of the DC input power supply. It has the advantages of simple structure, flexible control, high output power, and strong device adaptability. It can be widely used in various non-isolated DC-DC conversion, high voltage positive control, full-bridge rectifier drive and other scenarios.

[0010] This utility model achieves the above objectives through the following technical solution: a power supply control circuit for a high-side drive pump, comprising:

[0011] A pump power controller is used to generate a drive control signal and adjust the drive control signal according to an error signal;

[0012] The drive module is electrically connected to the pump power controller and is used to receive the drive control signal and drive the switching elements of the power conversion unit.

[0013] The power conversion unit includes at least a switching element and an energy storage element, and is configured to boost the DC input voltage to a pump voltage under the control of the drive module according to the drive control signal.

[0014] A feedback sampling circuit is used to sample the pump voltage and generate an error signal;

[0015] An isolation feedback device, whose input terminal is connected to the feedback sampling circuit and whose output terminal is connected to the feedback input terminal of the pump power controller, is used to transmit the error signal to the pump power controller in a potential isolation manner;

[0016] The pump power controller uses the negative terminal of the DC input power supply as a reference to ground, and the pump voltage uses the positive terminal of the DC input power supply as a reference, thereby achieving closed-loop stable control of the high-side output voltage.

[0017] Furthermore, the power conversion unit includes two power switches Q1 and Q2 and an inductor L1, wherein the two power switches Q1 and Q2 are connected in series with the inductor L1 to form a boost main power circuit;

[0018] The driving module is a half-bridge driver or a bootstrap driving circuit, used to generate complementary driving signals to alternately turn on the power switching transistors.

[0019] Furthermore, the two power switches Q1 and Q2 are N-channel MOSFETs;

[0020] The isolation feedback device is an optically coupled isolation device.

[0021] Furthermore, it also includes at least one filter capacitor C1 or C2 connected in parallel to the pump voltage output terminal for filtering and energy buffering the pump voltage;

[0022] The feedback sampling circuit includes a first sampling resistor R1 and a second sampling resistor R2 connected in series, and the error signal is obtained at the voltage divider node of the first sampling resistor R1 and the second sampling resistor R2.

[0023] Furthermore, the feedback sampling circuit also includes a reference regulator U1 connected to the voltage divider node, used to compare the pump voltage with a preset reference voltage.

[0024] Furthermore, the pump power controller is a microcontroller (MCU), FPGA, or a dedicated PWM control chip.

[0025] Furthermore, it also includes two filter capacitors C1 and C2 connected in parallel to the pump voltage output terminal, used for filtering and energy buffering the pump voltage;

[0026] A resistor-capacitor voltage divider circuit is connected in series between the filter capacitors C1 and C2 to improve voltage stability and response speed.

[0027] Furthermore, the pump voltage is defined as the potential difference between the pump voltage output terminal POUT+ and the positive terminal DC+ of the DC input power supply, and supplies power to the high-side load at a preset constant value. Specifically, the voltage between the pump voltage output terminal POUT+ and the positive terminal DC+ of the DC input power supply is a set constant value, used to provide a stable voltage supply to the high-side load.

[0028] The beneficial effects of this utility model are:

[0029] 1. Strong power output: The main power circuit adopts inductor energy storage and is equipped with high-current MOSFETs, which can achieve stable current output at the ampere level, breaking through the power bottleneck of traditional charge pump circuits;

[0030] 2. Stable voltage control: The feedback sampling circuit with sampling circuit and optocoupler feedback forms a closed-loop regulation mechanism, which has high output voltage stability and is suitable for occasions with strict voltage accuracy requirements.

[0031] 3. Simple and efficient control circuit: The controller can use a general-purpose MCU, which has simple logic, low cost, and flexible control method;

[0032] 4. Enables high-side control: The optocoupler isolates the high potential from the control ground, adapting to high-side drive requirements;

[0033] 5. Wide range of applications: This solution is applicable to various DC-DC power conversion, high-side MOSFET driving, battery pack positive terminal control, lossless rectifier circuits and other scenarios;

[0034] 6. Wide range of device selection: N-type MOSFETs are used as the main control device, and the device is highly compatible with common market devices, which facilitates mass production and cost reduction.

[0035] Therefore, this utility model is a pump power supply control scheme that is suitable for high-side drive applications, has a novel structure, stable performance, flexible control, and controllable cost, and has good prospects for promotion and application. Attached Figure Description

[0036] Figure 1 is a schematic diagram of a charge pump voltage multiplier circuit in the prior art.

[0037] Figure 2 is a schematic diagram of the pump power supply control circuit structure of this utility model. Detailed Implementation

[0038] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. It is understood that the accompanying drawings are provided for reference and illustration only, and are not intended to limit the present invention. The connection relationships shown in the accompanying drawings are only for clear description and do not limit the connection method.

[0039] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model; the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, unless otherwise explicitly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly, for example, as a fixed connection, a detachable connection, or an integral connection; a mechanical connection or an electrical connection; a direct connection or an indirect connection through an intermediate medium; or a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances. The terminology used in this specification is only for the purpose of describing specific embodiments and is not intended to limit the invention.

[0040] In existing technology, as shown in Figure 1, the working principle of a conventional charge pump is as follows: High-level clock switches CLK1 and CLK2 are derived from a dedicated control circuit. Their operation involves SW1 and SW4 controlled by clock CLK1 to achieve synchronous high-speed switching. Similarly, SW2 and SW3 are controlled by clock CLK2. The clocks CLK2 and CLK1 maintain a 180-degree phase shift. The input DC power supply VCC-IN is modulated by switches SW1-SW4, and voltage doubled and rectified by capacitors C1 and C2, resulting in an output voltage VCC-OUT that is twice the input voltage VCC-IN. Similarly, to achieve an even higher output voltage, capacitors and a switching clock are cascaded, but this increases control complexity. Analysis of the principle reveals that the output power of this circuit relies on capacitor storage, and is significantly limited by the charging and discharging speed. This severely restricts its application, and the control circuit is also quite complex (a dedicated clock control circuit). In detail, C1 is the intermediate capacitor, C2 is the output capacitor, and there are four switches (SW1~SW4). These are not manually turned on, but controlled by two clock signals (CLK1, CLK2), like two "invisible hands" that alternately turn the switches on and off. Simplified working process: Step 1: Charging stage (T1) SW1 and SW4 are on; the power supply VCC-IN charges C1; C2 is also attempting to output current through SW4. Step 2: Voltage boosting stage (T2) SW2 and SW3 are on; the current that C1 was originally charging is now connected above VCC-IN; therefore, VCC-OUT sees the voltage of VCC-IN + C1 (superimposed).

[0041] Problems and drawbacks of this circuit:

[0042] 1. Low output current. Because the capacitor can only store a limited amount of electricity, like a small bucket, it is not suitable for large discharges; the output voltage drops as soon as it discharges, making it suitable for "light load" applications.

[0043] 2. Complex control. CLK1 and CLK2 require precise control by specialized circuitry and cannot be staggered or jump randomly, otherwise they will fail.

[0044] 3. Selection difficulties. Due to the need for rapid switching of high voltage, many commonly used electronic switches are not suitable, and only P-type devices can be used; however, P-type devices have fewer types and higher losses under high voltage.

[0045] As shown in Figure 2, this embodiment of the present invention provides a power supply control circuit for a high-side drive pump, including:

[0046] The pump power controller is the core of the entire circuit control. It can be an MCU, FPGA or a dedicated PWM chip, used to adjust the switching frequency or duty cycle according to the feedback signal.

[0047] The drive module is used to drive the main power switches Q1 and Q2, using either a half-bridge drive or a bootstrap method.

[0048] The main power circuit consists of MOSFETs Q1 and Q2, inductor L1, and capacitors C1 and C2, and is used to boost the DC input voltage to the set high-side voltage.

[0049] Filtering unit: Capacitors C1 and C2 are used for output voltage filtering to ensure stable voltage output;

[0050] Sampling and reference circuit: R1 and R2 form a voltage divider sampling network, and U1 is a voltage reference source;

[0051] Optocoupler feedback module U2: Used to isolate the error signal of the high-side output voltage and transmit it to the controller to form a closed-loop control;

[0052] The output terminal POUT+ is the high-side drive voltage output point after the boost, and POUT- / DC+ is the system reference positive terminal. The controller is grounded at the DC negative terminal for calculation and regulation, successfully achieving a stable voltage output across the potential.

[0053] In detail:

[0054] DC input power supply: serves as the power source for the entire pump power control circuit, and its negative terminal serves as the common reference ground for the entire controller and drive module.

[0055] Pump power controller: can be a microcontroller (MCU), FPGA, or PWM control chip, with an integrated PWM pulse output terminal for generating control drive signals;

[0056] The driver module is used to amplify the PWM signal output by the controller and drive the main power MOSFETs Q1 and Q2. The driver module can be a half-bridge driver chip, such as IR2104, IR2110, etc.

[0057] Main power circuit: MOSFETs Q1 and Q2 are N-channel power transistors, with their sources connected to the negative DC terminal. The drain of Q1 is connected to one end of inductor L1, and the drain of Q2 is connected to the other end of L1. The midpoint of inductor L1 is connected to the positive terminal of C1, and the negative terminal of C1 is connected to the positive DC terminal. C2 is connected in parallel between the output terminals POUT+ and POUT- / DC+ to filter the output voltage.

[0058] Output ports: POUT+ is the positive terminal of the pump voltage output; POUT- / DC+ is connected to the positive terminal of the DC power supply and is used as the output reference.

[0059] Voltage sampling and feedback loop: R1 and R2 are connected in series between POUT+ and POUT- / DC+ to form a voltage divider; the voltage divider node is connected to the input terminal of the reference Zener diode U1; the output of Zener diode U1 is connected to the input terminal of optocoupler U2; the output terminal of optocoupler U2 is connected to the feedback pin of the pump power controller; other resistors and capacitors: R3~R5 are current limiting and bias resistors; the above components form a feedback and level conversion network to ensure that the error signal accurately reflects the pump voltage status.

[0060] The controller generates a PWM signal, which is then sent to the drive module. The drive module outputs two complementary control signals, which control Q1 and Q2 to conduct respectively. Q1, Q2, and L1 form a boost circuit: when Q1 is on, L1 stores energy; when Q1 is off and Q2 is on, L1 releases energy to C1 and C2, thus boosting the pump voltage. The output voltage is smoothed by capacitor C2 and then output to the load PUMPDC. The output terminal POUT+ is connected to the Zener reference transistor U1 for comparison after passing through voltage divider resistors R1 and R2. The Zener transistor outputs a deviation signal, which is isolated by optocoupler U2 and input to the controller feedback pin. The controller compares the feedback voltage with the set target, adjusts the PWM duty cycle, and controls the pump voltage to rise or fall, thus achieving closed-loop regulation.

[0061] Working principle: The core function of this circuit is to "float" the DC power supply voltage on a high potential and output the pump voltage (POUT+) to provide stable drive for high-side devices (such as MOSFETs or bridge arms).

[0062] Its principle is divided into three stages:

[0063] 1. Charging stage (Q1 is on):

[0064] The controller turns Q1 on and Q2 off. Current flows from DC+ through L1 to ground, and L1 stores magnetic energy.

[0065] 2. Lifting phase (Q1 off, Q2 on):

[0066] The controller turns off Q1 and turns on Q2. L1 releases energy, and the current flows from the inductor output terminal through Q2 to the output terminal, which pushes up the output voltage, forming a POUT+ potential higher than DC+.

[0067] 3. Closed-loop stability control:

[0068] The output voltage is divided by R1 and R2 and compared with the target voltage through the Zener diode U1. If the output is too low, it is fed back to the controller to adjust the duty cycle to increase; if the output is too high, it is reduced to keep the output voltage stable.

[0069] This solution has the following significant advantages over existing technologies:

[0070] 1. High output power: This solution uses inductors Q1, Q2 and L1 to form the main power circuit, which has higher energy storage and voltage boosting efficiency and can output stable current of ampere level or above to meet the needs of high power industrial applications.

[0071] 2. Stable output voltage: The high-potential output error is linearly converted into a feedback signal of the controller's reference ground potential through the optocoupler isolation feedback structure (U2), realizing closed-loop stable control, high output voltage accuracy, and strong anti-interference ability.

[0072] 3. Flexible control and wide selection of components: This solution uses a standard N-type MOSFET as the main control device, combined with a programmable controller or a dedicated PWM control chip, to achieve flexible control. It has a wide variety of components, low power consumption, and is suitable for different voltage levels.

[0073] 4. High safety due to optocoupler isolation design: The optocoupler U2 achieves potential isolation of the control reference point, improving the system's anti-interference capability and ensuring the safe operation of the controller.

[0074] 5. Wide range of applications: This circuit is suitable for various non-isolated DC-DC conversion, high-side drive control, lossless rectifier circuits with positive control, high-voltage power supply drive for battery packs, and other scenarios, and supports flexible configuration from milliwatt level to hundred-watt level.

[0075] The high-side drive pump power supply control circuit of this solution no longer relies on the interleaved clock and capacitor energy storage mechanism of traditional charge pumps, but uses a power inductor and MOSFET for direct control, resulting in strong output capability.

[0076] The introduction of optocoupler U2 enables the isolation conversion of the reference potential from "high-side floating" to "control ground", allowing the controller to still operate within the normal potential range;

[0077] The overall structure is simple, the control is flexible, and it can adapt to a variety of loads; the expandable design can meet the application of different voltage levels (such as 12V, 24V, 48V or even hundreds of volts) and power levels (milliwatts to hundreds of watts).

[0078] Examples of applicable scenarios: High-side MOSFET control in battery management systems (BMS); power supply for high-side drive devices in full-bridge or half-bridge power supply circuits; bidirectional non-isolated DC-DC power modules; high-voltage bus positive electronic switching systems (such as electric vehicle bus switches); auxiliary power supply systems for low-cost high-voltage control devices.

[0079] In the specification and claims of this application, the terms "comprising / including" and "having / including" and variations thereof are used to specify the presence of the stated features, values, steps or components, but do not exclude the presence or addition of one or more other features, values, steps, components or combinations thereof.

[0080] Some features of the present invention are described in different embodiments for clarity; however, these features may also be described in combination in a single embodiment. Conversely, some features of the present invention are described only in a single embodiment for brevity; however, these features may also be described individually or in any suitable combination in different embodiments.

[0081] Finally, it should be noted that any cross-referencing or superposition of the various embodiments of this solution by those skilled in the art still falls within the original disclosure scope of this solution. Furthermore, the above descriptions are merely preferred embodiments of this utility model and are not intended to limit this utility model. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A power supply control circuit for a high-side driven pump, characterized in that, include: A pump power controller is used to generate a drive control signal and adjust the drive control signal according to an error signal; A drive module, electrically connected to the pump power controller, is used to receive the drive control signal; a power conversion unit, including at least a switching element and an energy storage element, is configured to boost the DC input voltage to the pump voltage under the control of the drive module according to the drive control signal. A feedback sampling circuit is used to sample the pump voltage and generate an error signal; an isolation feedback device is connected to the feedback sampling circuit at its input and to the feedback input of the pump power controller at its output, and is used to transmit the error signal to the pump power controller in a potential-isolated manner; wherein, the pump power controller uses the negative terminal of the DC input power supply as a reference to ground, and the pump voltage uses the positive terminal of the DC input power supply as a reference.

2. The power supply control circuit for a high-side drive pump according to claim 1, characterized in that, The power conversion unit includes two power switches Q1 and Q2 and an inductor L1. The two power switches Q1 and Q2 are connected in series with the inductor L1 to form a boost main power circuit. The driving module is a half-bridge driver or a bootstrap driving circuit, used to generate complementary driving signals to alternately turn on the power switches.

3. The power supply control circuit for a high-side drive pump according to claim 2, characterized in that, The two power switches Q1 and Q2 are N-channel MOSFETs; the isolation feedback device is an optocoupler.

4. The power supply control circuit for a high-side drive pump according to claim 3, characterized in that, It also includes at least one filter capacitor C1 or C2 connected in parallel to the pump voltage output terminal for filtering and energy buffering the pump voltage; the feedback sampling circuit includes a first sampling resistor R1 and a second sampling resistor R2 connected in series, and the error signal is obtained at the voltage divider node of the first sampling resistor R1 and the second sampling resistor R2.

5. The power supply control circuit for a high-side drive pump according to claim 4, characterized in that, The feedback sampling circuit also includes a reference regulator U1 connected to the voltage divider node, used to compare the pump voltage with a preset reference voltage.

6. The power supply control circuit for a high-side drive pump according to claim 1, characterized in that, The pump power controller is a microcontroller (MCU), FPGA, or a dedicated PWM control chip.

7. The power supply control circuit for a high-side drive pump according to claim 4, characterized in that, It also includes two filter capacitors C1 and C2 connected in parallel to the pump voltage output terminal for filtering and energy buffering of the pump voltage; a resistor-capacitor voltage divider circuit is connected in series between the filter capacitors C1 and C2 to improve voltage stability and response speed.

8. The power supply control circuit for a high-side drive pump according to claim 1, characterized in that, The pump voltage is defined as the potential difference between the pump voltage output terminal POUT+ and the positive terminal DC+ of the DC input power supply, and supplies power to the high-side load at a preset constant value.

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