A direct current voltage conversion stabilizing circuit

Abstract

This utility model relates to a DC voltage conversion and regulation circuit, comprising: an input terminal for receiving an input voltage; an output terminal for providing an output voltage; an adjustable voltage regulator connected between the input and output terminals for converting the input voltage into an output voltage; the adjustable voltage regulator having a reference voltage terminal, a cathode, and an anode, with the cathode connected to the output terminal; a first voltage divider resistor and a second voltage divider resistor for setting the reference voltage of the adjustable voltage regulator; the first voltage divider resistor is disposed between the input terminal and the reference voltage terminal of the adjustable voltage regulator, and the second voltage divider resistor is disposed between the reference voltage terminal of the adjustable voltage regulator and a ground terminal; the anode of the adjustable voltage regulator is connected to the ground terminal. This utility model eliminates the need for inductors, requires fewer external components, is low-cost, and easy to design. By adjusting the resistance values ​​of the first and second voltage divider resistors, the output voltage can be flexibly adjusted to adapt to different application requirements.

Description

Technical Field

[0001] This utility model relates to the field of voltage conversion technology, and in particular to a DC voltage conversion and regulation circuit. Background Technology

[0002] With the widespread application and development of electronic devices, the demand for power conversion circuits is increasing. Especially in battery-powered or automotive electronic devices, it is often necessary to convert a fixed DC voltage to another stable DC voltage to meet the operating requirements of different electronic components. For example, many microcontrollers and sensor modules operate at 5V or 3.3V, while batteries or power supplies may provide 12V or higher. Conventional 12V to 5V DC voltage regulator circuits typically use three-terminal regulator chips such as the 78L05, but these have drawbacks such as low accuracy and non-adjustable output voltage. Utility Model Content

[0003] Therefore, the technical problem to be solved by this utility model is to overcome the shortcomings of the prior art and provide a DC voltage conversion and regulation circuit that does not require the use of inductors, has fewer external components, simplifies circuit design, reduces costs, and reduces electromagnetic compatibility issues.

[0004] To solve the above-mentioned technical problems, this utility model provides a DC voltage conversion and regulation circuit, comprising:

[0005] The input terminal is used to receive the input voltage.

[0006] The output terminal is used to provide the output voltage.

[0007] An adjustable voltage regulator is connected between the input terminal and the output terminal to convert the input voltage into an output voltage; the adjustable voltage regulator is provided with a reference voltage terminal, a cathode, and an anode; the cathode is connected to the output terminal;

[0008] The first voltage divider resistor and the second voltage divider resistor are used to set the reference voltage of the adjustable voltage regulator. The first voltage divider resistor is located between the input terminal and the reference voltage terminal of the adjustable voltage regulator, and the second voltage divider resistor is located between the reference voltage terminal of the adjustable voltage regulator and the ground terminal. The anode of the adjustable voltage regulator is connected to the ground terminal. The resistance ratio of the first voltage divider resistor and the second voltage divider resistor is used to set the reference voltage of the adjustable voltage regulator, thereby adjusting the output voltage.

[0009] In one embodiment of this utility model, a current-limiting resistor is further included. The current-limiting resistor is disposed between the input terminal and the cathode of the adjustable voltage regulator to limit the current flowing through the adjustable voltage regulator.

[0010] In one embodiment of this utility model, the resistance value of the current-limiting resistor is calculated based on the input voltage, the output voltage, and the operating current of the adjustable voltage regulator.

[0011] In one embodiment of the present invention, a filter capacitor element is further included, disposed between the cathode and the ground terminal of the adjustable voltage regulator, for reducing the noise of the output voltage.

[0012] In one embodiment of this utility model, the filter capacitor element includes a first filter capacitor and a second filter capacitor, which are connected in parallel.

[0013] In one embodiment of this utility model, the first filter capacitor is an electrolytic capacitor; the second filter capacitor is a ceramic capacitor.

[0014] In one embodiment of this utility model, a compensation capacitor is further included, which is disposed between the first filter capacitor and the cathode of the adjustable voltage regulator.

[0015] In one embodiment of this utility model, the capacitance value of the first filter capacitor is 10uF, the capacitance value of the second filter capacitor is 100nF, and the capacitance value of the compensation capacitor is 100nF.

[0016] In one embodiment of this utility model, the resistance values ​​of the first voltage divider resistor and the second voltage divider resistor can be selected or adjusted according to the required output voltage.

[0017] In one embodiment of this utility model, the adjustable voltage regulator is a TL431 voltage regulator.

[0018] In one embodiment of this utility model, the reference voltage at the reference voltage terminal of the TL431 voltage regulator is 2.495V.

[0019] In one embodiment of this utility model, the input voltage at the input terminal is 12V, and the output voltage at the output terminal is 5V.

[0020] Compared with the prior art, the above-mentioned technical solution of this utility model has the following beneficial effects:

[0021] The DC voltage conversion and regulation circuit described in this utility model does not require the use of inductors, has few external components, is low-cost, and easy to design. By adjusting the resistance values ​​of the first and second voltage divider resistors, the output voltage can be flexibly adjusted to meet different application requirements. Attached Figure Description

[0022] To make the content of this utility model easier to understand, the present utility model will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0023] Figure 1 This is a schematic diagram of the DC voltage conversion and regulation circuit in a preferred embodiment of the present invention. Detailed Implementation

[0024] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments are not intended to limit the present invention.

[0025] Reference Figure 1 As shown, this utility model discloses a DC voltage conversion and regulation circuit, comprising:

[0026] The input terminal is used to receive the input voltage V. in ;

[0027] The output terminal is used to provide the output voltage V. out ;

[0028] The first voltage divider resistor R1 and the second voltage divider resistor R2 are used to set the reference voltage of the adjustable voltage regulator U1. The first voltage divider resistor R1 is located between the input terminal and the reference voltage terminal 1 of the adjustable voltage regulator U1, and the second voltage divider resistor R2 is located between the reference voltage terminal 1 of the adjustable voltage regulator U1 and the ground terminal GND. The anode 3 of the adjustable voltage regulator U1 is connected to the ground terminal GND. The resistance ratio of the first voltage divider resistor R1 and the second voltage divider resistor R2 is used to set the reference voltage V of the adjustable voltage regulator U1. vef This allows for the adjustment of the output voltage V. out .

[0029] This embodiment also includes a current-limiting resistor R. limit The current-limiting resistor R limit A current-limiting resistor R is positioned between the input terminal and the cathode 2 of the adjustable voltage regulator U1 to limit the current flowing through the adjustable voltage regulator U1. limit The use of this not only protects the adjustable voltage regulator U1 from overcurrent damage, but also simplifies the protection design of the circuit.

[0030] Furthermore, it also includes a filter capacitor, disposed between the cathode 2 of the adjustable voltage regulator U1 and the ground terminal GND, for reducing the output voltage V. out The noise.

[0031] In this embodiment, the filter capacitors include a first filter capacitor C2 and a second filter capacitor C3, which are connected in parallel.

[0032] Preferably, the first filter capacitor C2 is an electrolytic capacitor; the second filter capacitor is a 100nF ceramic capacitor.

[0033] Furthermore, it also includes a compensation capacitor C1, which is disposed between the first filter capacitor C2 and the cathode 2 of the adjustable voltage regulator U1. The use of the compensation capacitor C1 provides necessary phase compensation, prevents circuit oscillation, and improves the stability and reliability of the circuit.

[0034] The first filter capacitor has a capacitance of 10uF, the second filter capacitor has a capacitance of 100nF, and the compensation capacitor has a capacitance of 100nF.

[0035] In practical applications, the resistance values ​​of the first voltage divider resistor R1 and the second voltage divider resistor R2 can be determined according to the required output voltage V. out Make selections or adjustments.

[0036] Preferably, the adjustable voltage regulator U1 is a TL431 voltage regulator. The reference voltage V at the reference voltage terminal of the TL431 voltage regulator... vef It is 2.495V.

[0037] R of the current-limiting resistor limit The resistance value can be determined based on the input voltage V. in Output voltage V out and the operating current I of the adjustable voltage regulator U1 ka The calculation is as follows:

[0038] R limit = (V in -V out ) / I ka

[0039] Due to the operating current I ka It cannot work properly below 1mA. In this embodiment, I ka Take 10mA.

[0040] When the input voltage V at the input terminal in The output voltage V at the output terminal is 12V. out When it is 5V, R limit = (12-5) / 10mA = 700Ω, therefore, the current-limiting resistor R limit The resistance is set to 680Ω, which ensures that the TL431 regulator can operate within the 1100mA range.

[0041] In this embodiment, the reference voltage V vef With input voltage V in The relationship is as follows:

[0042] V vef = V in ×(1+(R2 / R1))

[0043] Output voltage V out With reference voltage V vef The relationship is as follows:

[0044] V out =V vef ×(1+(R1 / R2))

[0045] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the protection scope of this invention.

Claims

1. A DC voltage conversion and regulation circuit, characterized in that, include: The input terminal is used to receive the input voltage. The output terminal is used to provide the output voltage. An adjustable voltage regulator is connected between the input terminal and the output terminal to convert the input voltage into an output voltage; the adjustable voltage regulator is provided with a reference voltage terminal, a cathode and an anode, and the cathode is connected to the output terminal; The first voltage divider resistor and the second voltage divider resistor are used to set the reference voltage of the adjustable voltage regulator. The first voltage divider resistor is located between the input terminal and the reference voltage terminal of the adjustable voltage regulator, and the second voltage divider resistor is located between the reference voltage terminal of the adjustable voltage regulator and the ground terminal. The anode of the adjustable voltage regulator is connected to the ground terminal. The resistance ratio of the first voltage divider resistor and the second voltage divider resistor is used to set the reference voltage of the adjustable voltage regulator, thereby adjusting the output voltage.

2. The DC voltage conversion and regulation circuit according to claim 1, characterized in that: It also includes a current-limiting resistor, which is disposed between the input terminal and the cathode of the adjustable voltage regulator to limit the current flowing through the adjustable voltage regulator.

3. The DC voltage conversion and regulation circuit according to claim 2, characterized in that: The resistance value of the current-limiting resistor is calculated based on the input voltage, output voltage, and operating current of the adjustable voltage regulator.

4. The DC voltage conversion and regulation circuit according to claim 1, characterized in that: It also includes a filter capacitor element, which is disposed between the cathode and the ground terminal of the adjustable voltage regulator to reduce the noise of the output voltage.

5. A DC voltage conversion and regulation circuit according to claim 4, characterized in that: The filter capacitor element includes a first filter capacitor and a second filter capacitor, which are connected in parallel.

6. The DC voltage conversion and regulation circuit according to claim 5, characterized in that: The first filter capacitor is an electrolytic capacitor; the second filter capacitor is a ceramic capacitor.

7. A DC voltage conversion and regulation circuit according to claim 6, characterized in that: It also includes a compensation capacitor, which is disposed between the first filter capacitor and the cathode of the adjustable voltage regulator.

8. The DC voltage conversion and regulation circuit according to claim 7, characterized in that: The first filter capacitor has a capacitance of 10uF, the second filter capacitor has a capacitance of 100nF, and the compensation capacitor has a capacitance of 100nF.

9. A DC voltage conversion and regulation circuit according to claim 1, characterized in that: The resistance values ​​of the first voltage divider resistor and the second voltage divider resistor can be selected or adjusted according to the required output voltage.

10. A DC voltage conversion and regulation circuit according to claim 1, characterized in that: The adjustable voltage regulator is a TL431 voltage regulator.

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