High-efficiency adjustable linear circuit

Abstract

The utility model relates to the technical field of switching power supplies, and discloses a high-efficiency adjustable linear circuit, which comprises a BACK circuit, a control circuit, an MCU and a low dropout regulator LDO, the BACK circuit comprises a DC / DC chip, the VCCOUT end of the DC / DC chip is electrically connected with the low dropout regulator LDO, the low dropout regulator LDO comprises a triode Q5, a triode M3, a capacitor C81, a resistor R65 and a resistor R59, and the triode Q5, the triode M3, the capacitor C81, the resistor R65 and the resistor R59 are electrically connected with the control circuit. The VCCOUT end of the DC / DC chip is conducted with the C ends of the triode Q5 and the triode M3, the E end of the triode Q5 is connected to the OUT-end through a resistor R65, the E end of the triode M3 is connected to the OUT + end, and the OUT + end is connected with the control circuit. The circuit is low in power consumption and high in efficiency, voltage and current output by the low dropout linear stabilizer LDO are in a linear relation, stability and reliability of the circuit are improved, voltage drop can be reduced, efficiency can be improved, and heating can be reduced due to the fact that following type dropout voltage control is adopted.

Description

Technical Field

[0001] This utility model relates to the field of switching power supply technology, and in particular to a high-efficiency adjustable linear circuit. Background Technology

[0002] Switching power supplies are high-efficiency, high-stability power converters widely used in various electronic devices. Even with significant input voltage variations, switching power supplies maintain stable output. Furthermore, they eliminate the need for bulky power frequency transformers and have low internal power consumption, resulting in a significant reduction in size and weight.

[0003] Because switching power supplies are relatively small, many components are crammed together, resulting in poor internal heat dissipation. Furthermore, switching power supplies may generate noise and electromagnetic interference during high-frequency switching. Low-dropout linear regulators (LDOs) can effectively filter out high-frequency noise in the power supply using capacitors.

[0004] Therefore, those skilled in the art have designed a highly efficient adjustable linear circuit that not only has low power consumption and high efficiency, but also has a linear relationship between the voltage and current output by the low dropout linear regulator (LDO), thereby improving the stability and reliability of the circuit and solving the problems mentioned in the background art. Utility Model Content

[0005] The purpose of this invention is to address the shortcomings of existing technologies and provide a high-efficiency adjustable linear circuit. This circuit not only has low power consumption and high efficiency, but also features a linear relationship between the voltage and current output by the low dropout linear regulator (LDO), thereby improving the stability and reliability of the circuit.

[0006] To achieve the above objectives, this utility model provides a high-efficiency adjustable linear circuit, comprising:

[0007] The circuit includes a BACK circuit, a control circuit, an MCU, and a low-dropout linear regulator (LDO). The BACK circuit includes a DC / DC chip, the VCC_OUT terminal of which is electrically connected to the LDO. The LDO includes transistors Q5 and M3, capacitor C81, and resistors R65 and R59. The VCC_OUT terminal of the DC / DC chip is connected to the collector (C) terminals of transistors Q5 and M3. The emitter (E) terminal of transistor Q5 is connected to the OUT- terminal through resistor R65, and the emitter (E) terminal of transistor M3 is connected to the OUT+ terminal. The OUT+ terminal is connected to the control circuit.

[0008] The control circuit is electrically connected to the conducting terminal of transistor Q5. The emitter terminal of transistor Q5 is also electrically connected to the conducting terminal of transistor M3. The operating potential of transistor M3 is controlled by controlling the conduction degree of transistor Q5, thereby controlling and adjusting the output voltage.

[0009] With the above technical solution, when a voltage is input to the DC / DC chip, the voltage is transmitted to the low dropout linear regulator (LDO) through the VCC_OUT terminal. The voltage difference is controlled by the control circuit to turn on the transistor Q5. The operating potential of the transistor M3 is controlled by controlling the conduction degree of the transistor Q5, thereby controlling and adjusting the output voltage. The output voltage is transmitted to the OUT+ terminal through resistors R65 and R59 and capacitor C81. Resistor R65 in the LDO can limit the maximum current passing through it, preventing damage due to overload.

[0010] Furthermore, it also includes a feedback adjustment terminal, which is bidirectionally electrically connected to the DC / DC chip and also bidirectionally electrically connected to the MCU;

[0011] Through the above technical solution, the MCU collects the voltage and current transmitted to the control circuit through the OUT+ terminal, determines whether the output voltage and current are within the set parameter range, performs PID adjustment on the output voltage and current setting correction, and transmits the adjusted voltage and current to the DC / DC chip through the feedback adjustment terminal. The DC / DC chip adjusts the output voltage of the DC / DC chip according to the output voltage of the load terminal to reduce the voltage difference between the linear voltage and the load voltage.

[0012] Furthermore, the pins at the front end of the DC / DC chip are connected to the positive and negative terminals of the input voltage, and the GND terminal of the DC / DC chip is grounded;

[0013] The above technical solution allows for the input voltage to the DC / DC chip via the input voltage terminal, and grounding via the GND terminal to ensure circuit connection safety.

[0014] Furthermore, the control circuit is bidirectionally electrically connected to the MCU;

[0015] Through the above technical solution, the MCU collects the voltage and current transmitted to the control circuit through the OUT+ terminal, determines whether the output voltage and current are within the set parameter range, and performs PID adjustment on the output voltage and current setting correction.

[0016] Furthermore, the resistor R59 is connected in parallel in the circuit where the rear ends of the transistor M3 and the resistor R65 are respectively connected to the OUT+ and OUT- terminals.

[0017] With the above technical solution, when the LDO needs to be quickly powered off, the resistor R59 connected in parallel at the output terminal can provide a discharge path to prevent the accumulation of charge on capacitor C81 from causing the voltage to be too high.

[0018] Furthermore, the capacitor C81 is connected in parallel with the rear end of the resistor R59 in a circuit that connects to the OUT+ and OUT- terminals;

[0019] Through the above technical solution, capacitor C81 in the circuit can not only filter out high-frequency noise in the power supply and ensure that the output voltage of the LDO is more stable, but also act as a temporary power supply during the LDO startup process to prevent excessive startup current caused by the output voltage being 0V.

[0020] Furthermore, the resistance of resistor R65 is 10KΩ, and the resistance of resistor R59 is 200Ω.

[0021] This utility model has the following beneficial effects:

[0022] 1. This utility model proposes a high-efficiency adjustable linear circuit. This circuit not only has low power consumption and high efficiency, but also the voltage and current output by the low dropout linear stabilizer (LDO) are linearly related, which improves the stability and reliability of the circuit.

[0023] 2. The present invention proposes a high-efficiency adjustable linear circuit. The MCU transmits the adjusted voltage and current to the DC / DC through feedback regulation. The DC / DC adjusts the output of the DC / DC according to the output voltage of the load terminal to reduce the voltage difference between the linear voltage and the load voltage. This reduces the linear voltage drop, lowers power consumption, and improves efficiency. The follower-type voltage difference control can reduce voltage drop, improve efficiency, and reduce heat generation. Attached Figure Description

[0024] Figure 1 The circuit connection diagram is provided for a high-efficiency adjustable linear circuit proposed in this utility model. Detailed Implementation

[0025] The present invention will now be further described with reference to the accompanying drawings.

[0026] Reference Figure 1 As shown, this utility model provides a specific embodiment:

[0027] A high-efficiency adjustable linear circuit includes a BACK circuit, a control circuit, an MCU, and a low-dropout linear regulator (LDO). The BACK circuit includes a DC / DC chip, the VCC_OUT terminal of which is electrically connected to the LDO. The LDO includes transistors Q5 and M3, capacitor C81, and resistors R65 and R59. The VCC_OUT terminal of the DC / DC chip is connected to the collector (C) terminals of transistors Q5 and M3. The emitter (E) terminal of transistor Q5 is connected to the OUT- terminal through resistor R65, and the emitter (E) terminal of transistor M3 is connected to the OUT+ terminal. The OUT+ terminal is connected to the control circuit.

[0028] The control circuit is electrically connected to the conducting terminal of transistor Q5. The emitter terminal of transistor Q5 is also electrically connected to the conducting terminal of transistor M3. The operating potential of transistor M3 is controlled by controlling the conduction level of transistor Q5, thereby controlling and adjusting the output voltage.

[0029] When a voltage is input to the DC / DC chip, the voltage is transmitted to the low-dropout linear regulator (LDO) through the VCC_OUT terminal. The control circuit controls the voltage difference to turn on transistor Q5. By controlling the conduction level of transistor Q5, the operating potential of transistor M3 is controlled, thus controlling and adjusting the output voltage. The output voltage is transmitted to the OUT+ terminal through resistors R65 and R59 and capacitor C81. Resistor R65 in the LDO can limit the maximum current passing through it to prevent damage due to overload.

[0030] It also includes a feedback adjustment terminal, which is bidirectionally electrically connected to the DC / DC chip and also bidirectionally electrically connected to the MCU. The MCU collects the voltage and current transmitted to the control circuit through the OUT+ terminal, determines whether the output voltage and current are within the set parameter range, and performs PID adjustment on the output voltage and current setting correction. The MCU transmits the adjusted voltage and current to the DC / DC chip through the feedback adjustment terminal. The DC / DC chip adjusts its output voltage according to the load output voltage to reduce the voltage difference between the linear voltage and the load voltage.

[0031] The pins on the front end of the DC / DC chip are connected to the positive and negative terminals of the input voltage, and the GND terminal of the DC / DC chip is grounded. The input voltage is applied to the DC / DC chip through the input voltage terminal, and the connection safety of the circuit is ensured by grounding the GND terminal.

[0032] The control circuit and MCU are bidirectionally electrically connected. The MCU collects the voltage and current transmitted to the control circuit through the OUT+ terminal, determines whether the output voltage and current are within the set parameters, and performs PID adjustment to correct the output voltage and current settings. Resistor R59 is connected in parallel with the transistor M3 and the circuit where the back ends of resistor R65 are connected to the OUT+ and OUT- terminals respectively. When the LDO needs to be quickly powered off, the parallel resistor R59 at the output terminal can provide a discharge path to prevent the accumulation of charge on capacitor C81 from causing excessive voltage. Capacitor C81 is connected in parallel with the back ends of resistor R59 to the OUT+ and OUT- terminals. Capacitor C81 in the circuit can filter out high-frequency noise in the power supply to ensure a more stable output voltage of the LDO, and can also act as a temporary power supply during the LDO startup process to prevent excessive startup current caused by the output voltage being 0V. The resistance of resistor R65 is 10KΩ, and the resistance of resistor R59 is 200Ω.

[0033] Working principle: The input voltage is supplied to the DC / DC converter. The voltage is transmitted to the low dropout linear regulator (LDO) through the VCC_OUT terminal. The control circuit controls the voltage difference to turn on the transistor Q5. By controlling the conduction degree of transistor Q5, the operating potential of transistor M3 is controlled, thus controlling and adjusting the output voltage. The output voltage is transmitted to the OUT+ terminal through resistors R65 and R59 and capacitor C81. Resistor R65 in the LDO can limit the maximum current passing through it to prevent damage due to overload.

[0034] When the LDO needs to be quickly powered off, the parallel resistor R59 at the output terminal can provide a discharge path to prevent the accumulation of charge on the capacitor from causing the voltage to be too high. The capacitor C81 in the circuit can filter out high-frequency noise in the power supply to ensure that the output voltage of the LDO is more stable. It can also act as a temporary power supply during the LDO startup process to prevent the startup current from being too large when the output voltage is 0V.

[0035] Finally, the MCU collects the voltage and current transmitted to the control circuit through the OUT+ terminal, determines whether the output voltage and current are within the set parameter range, performs PID adjustment on the output voltage and current setting correction, and transmits the adjusted voltage and current to the DC / DC through feedback regulation. The DC / DC adjusts the output of the DC / DC according to the output voltage at the load terminal, reducing the voltage difference between the linear voltage and the load voltage, thereby reducing the linear voltage drop, reducing power consumption, and improving efficiency.

Claims

1. A high-efficiency adjustable linear circuit comprising a BACK circuit, a control circuit, an MCU and a low-dropout linear regulator (LDO), characterized in that: The BACK circuit includes a DC / DC chip. The VCC_OUT terminal of the DC / DC chip is electrically connected to a low dropout linear regulator (LDO). The LDO includes transistors Q5 and M3, capacitor C81, and resistors R65 and R59. The VCC_OUT terminal of the DC / DC chip is connected to the collector (C) terminals of transistors Q5 and M3. The emitter (E) terminal of transistor Q5 is connected to the OUT- terminal through resistor R65. The emitter (E) terminal of transistor M3 is connected to the OUT+ terminal, and the OUT+ terminal is connected to the control circuit. The control circuit is electrically connected to the conducting terminal of transistor Q5, and the emitter terminal of transistor Q5 is also electrically connected to the conducting terminal of transistor M3. The operating potential of transistor M3 is controlled by controlling the conduction level of transistor Q5, thereby controlling and adjusting the output voltage.

2. A high efficiency adjustable linear circuit according to claim 1, characterized in that: It also includes a feedback adjustment terminal, which is bidirectionally electrically connected to the DC / DC chip and also bidirectionally electrically connected to the MCU.

3. A high efficiency adjustable linear circuit according to claim 1, characterized in that: The pins at the front end of the DC / DC chip are connected to the positive and negative terminals of the input voltage, and the GND terminal of the DC / DC chip is grounded.

4. A high efficiency adjustable linear circuit according to claim 1, characterized in that: The control circuit is bidirectionally electrically connected to the MCU.

5. A high efficiency adjustable linear circuit according to claim 1, characterized in that: The resistor R59 is connected in parallel in the circuit where the back ends of transistor M3 and resistor R65 are connected to the OUT+ and OUT- terminals, respectively.

6. A high efficiency adjustable linear circuit according to claim 1, characterized in that: The capacitor C81 is connected in parallel to the rear end of the resistor R59 in the circuit that connects to the OUT+ and OUT- terminals.

7. A high efficiency adjustable linear circuit according to claim 1, wherein: The resistance of resistor R65 is 10KΩ, and the resistance of resistor R59 is 200Ω.

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