A voltage stabilizing chip-based step-down circuit

Abstract

The application provides a voltage reduction circuit based on a voltage stabilizing chip, wherein the input end of the voltage stabilizing chip, the first power input end of the first operational amplifier and the first end of the capacitor are connected to the positive pole of the power input end, the grounding end of the voltage stabilizing chip is connected to the first signal input end, the second signal input end and the signal output end of the first operational amplifier, the output end of the voltage stabilizing chip is connected to the first end of the first resistor, the first signal input end of the first operational amplifier, the second end of the first resistor, the first end of the second resistor and the first end of the first switch are connected to the positive pole of the power output end, the first end of the second switch is connected to the second end of the first switch, the second end of the second resistor and the first end of the third resistor are connected to the second end of the second switch, the second power input end of the first operational amplifier, the second end of the capacitor, the second end of the third resistor and the third end of the second switch are connected to the negative pole of the power supply, and multi-stage voltage output can be realized, and the application environment is more extensive.

Description

Technical Field

[0001] This invention relates to the field of electronic technology, and in particular to a step-down circuit based on a voltage regulator chip. Background Technology

[0002] With increasing global emphasis on energy issues, the energy consumption of electronic products is becoming increasingly prominent. Reducing standby power consumption and improving power supply efficiency have become urgent problems. While traditional linear regulated power supplies are simple in circuit structure and reliable in operation, they suffer from drawbacks such as low efficiency, large size, high copper and iron consumption, high operating temperature, and small adjustment range. To improve efficiency, switching power supplies have been developed. These power supplies achieve efficiencies of over 85%, have a wide voltage regulation range, and offer high voltage regulation accuracy without the need for a power transformer, making them a more ideal type of regulated power supply. For these reasons, switching power supplies are widely used in various electronic devices. However, existing switching power supplies generally suffer from poor output voltage stability and a fixed output voltage, making them unsuitable for applications in environments with diverse operating voltages. Summary of the Invention

[0003] Based on the above-mentioned problems, this invention proposes a step-down circuit based on a voltage regulator chip, which is applied to a switching power supply. The circuit has a simple structure, good power supply stability, can achieve multi-level voltage output, and has a wider range of applications.

[0004] In view of this, the present invention proposes a step-down circuit based on a voltage regulator chip, comprising a voltage regulator chip, a first operational amplifier, a capacitor, a first resistor, a second resistor, a third resistor, a first switch, and a second switch. The input terminal of the voltage regulator chip, the first power input terminal of the first operational amplifier, and the first terminal of the capacitor are connected to the positive terminal of the power input terminal of the step-down circuit. The ground terminal of the voltage regulator chip is connected to the first signal input terminal, the second signal input terminal, and the signal output terminal of the first operational amplifier. The output terminal of the voltage regulator chip is connected to the first terminal of the first resistor. The first signal input terminal of the first operational amplifier, the second terminal of the first resistor, the first terminal of the second resistor, and the first terminal of the first switch are connected to the positive terminal of the power output terminal of the step-down circuit. The first terminal of the second switch is connected to the second terminal of the first switch. The second terminal of the second resistor and the first terminal of the third resistor are connected to the second terminal of the second switch. The second power input terminal of the first operational amplifier, the second terminal of the capacitor, the second terminal of the third resistor, and the third terminal of the second switch are connected to the negative terminals of the power input terminal and the power output terminal of the step-down circuit. The negative terminals of the power input terminal and the power output terminal of the step-down circuit are grounded.

[0005] Preferably, the resistance values ​​R1 of the first resistor, R2 of the second resistor, and R3 of the third resistor satisfy R1 <R2<R3。

[0006] Preferably, the output voltage value of the step-down circuit is controlled by controlling the switching states of the first switch and the second switch to configure the states of the second resistor and the third resistor connected to the step-down circuit.

[0007] Preferably, when both the first switch and the second switch are closed, and the second switch is connected by connecting its first and third terminals, the output voltage V of the step-down circuit is... out =V Pout V Pout The voltage is the output voltage of the voltage regulator chip.

[0008] Preferably, when both the first switch and the second switch are closed, and the second switch is connected by connecting its first and second terminals, the output voltage value of the step-down circuit is... Where V Pout The voltage is the output voltage of the voltage regulator chip.

[0009] Preferably, when both the first switch and the second switch are in the open state, the output voltage value of the step-down circuit is... Where V Pout The voltage is the output voltage of the voltage regulator chip.

[0010] Preferably, the step-down circuit based on the voltage regulator chip further includes a fourth resistor, a fifth resistor, and a second operational amplifier. The first terminal of the fourth resistor and the first power input terminal, second signal input terminal, and signal output terminal of the second operational amplifier are connected to the positive terminal of the power input terminal of the step-down circuit. The first signal input terminal of the second operational amplifier and the first terminal of the fifth resistor are connected to the second terminal of the fourth resistor. The second terminal of the fifth resistor and the second power input terminal of the second operational amplifier are connected to the negative terminal of the power input terminal and power output terminal of the step-down circuit. The resistance values ​​R4 of the fourth resistor and R5 of the fifth resistor satisfy the following:

[0011]

[0012] Among them, V Pin This is the input voltage value of the voltage regulator chip.

[0013] Preferably, the resistance value R4 of the fourth resistor and the resistance value R5 of the fifth resistor satisfy the following:

[0014]

[0015] Among them, Min(V) Pin ) represents the minimum input voltage value within the applicable range of the voltage regulator chip, Max(V) Pin ) represents the maximum input voltage value within the adaptability range of the voltage regulator chip, ΔV Pin This represents the maximum voltage fluctuation value at the input terminal of the voltage regulator chip for the step-down circuit.

[0016] This invention proposes a step-down circuit based on a voltage regulator chip. The input terminal of the voltage regulator chip, the first power input terminal of the first operational amplifier, and the first terminal of the capacitor are connected to the positive terminal of the power input terminal. The ground terminal of the voltage regulator chip is connected to the first signal input terminal, the second signal input terminal, and the signal output terminal of the first operational amplifier. The output terminal of the voltage regulator chip is connected to the first terminal of the first resistor. The first signal input terminal of the first operational amplifier, the second terminal of the first resistor, the first terminal of the second resistor, and the first terminal of the first switch are connected to the positive terminal of the power output terminal. The first terminal of the second switch is connected to the second terminal of the first switch. The second terminal of the second resistor and the first terminal of the third resistor are connected to the second terminal of the second switch. The second power input terminal of the first operational amplifier, the second terminal of the capacitor, the second terminal of the third resistor, and the third terminal of the second switch are connected to the negative terminal of the power supply. This circuit can achieve multi-stage voltage output and has a wider range of applications. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of a step-down circuit based on a voltage regulator chip provided in one embodiment of the present invention;

[0018] Figure 2 This is a schematic diagram of a step-down circuit based on a voltage regulator chip provided in another embodiment of the present invention. Detailed Implementation

[0019] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0020] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0021] In the description of this invention, the term "multiple" refers to two or more. Unless otherwise explicitly defined, the terms "upper," "lower," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention 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 the invention. The terms "connect," "install," "fix," etc., should be interpreted broadly. For example, "connect" can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "multiple" means two or more.

[0022] In the description of this specification, the terms "one embodiment," "some implementations," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0023] A step-down circuit based on a voltage regulator chip, according to some embodiments of the present invention, will now be described with reference to the accompanying drawings.

[0024] like Figure 1As shown, this invention proposes a step-down circuit based on a voltage regulator chip, including a voltage regulator chip, a first operational amplifier OP1, a capacitor C, a first resistor R1, a second resistor R2, a third resistor R3, a first switch S1, and a second switch S2. The input terminal of the voltage regulator chip, the first power input terminal of the first operational amplifier OP1, and the first terminal of the capacitor C are connected to the positive terminal of the power input terminal of the step-down circuit. The ground terminal of the voltage regulator chip is connected to the first signal input terminal, the second signal input terminal, and the signal output terminal of the first operational amplifier OP1. The output terminal of the voltage regulator chip is connected to the first terminal of the first resistor R1. The first signal input terminal of the first operational amplifier OP1... The first terminal of the first resistor R1, the second terminal of the second resistor R2, and the first terminal of the first switch S1 are connected to the positive terminal of the power output terminal of the buck circuit. The first terminal of the second switch S2 is connected to the second terminal of the first switch S1. The second terminal of the second resistor R2 and the first terminal of the third resistor R3 are connected to the second terminal of the second switch S2. The second power input terminal of the first operational amplifier OP1, the second terminal of the capacitor C, the second terminal of the third resistor R3, and the third terminal of the second switch S2 are connected to the negative terminals of the power input and power output terminals of the buck circuit. The negative terminals of the power input and power output terminals of the buck circuit are grounded. In the above embodiment, by using a voltage regulator chip in the buck circuit, the output voltage of the buck circuit is more stable and has better reliability.

[0025] Preferably, the resistance values ​​R1 of the first resistor R1, R2 of the second resistor R2, and R3 of the third resistor R3 satisfy R1 <R2<R3。

[0026] Preferably, the output voltage value of the step-down circuit is controlled by controlling the switching states of the first switch S1 and the second switch S2 to configure the second resistor R2 and the third resistor R3 to be connected to the step-down circuit.

[0027] Preferably, when both the first switch S1 and the second switch S2 are closed, and the second switch S2 is connected by connecting its first and third terminals, the output voltage V of the step-down circuit is... out =V Pout V Pout The voltage is the output voltage of the voltage regulator chip.

[0028] Preferably, when both the first switch S1 and the second switch S2 are closed, and the second switch S2 is connected by connecting its first and second terminals, the output voltage value of the step-down circuit is... Where V Pout The voltage is the output voltage of the voltage regulator chip.

[0029] Preferably, when both the first switch S1 and the second switch S2 are in the open state, the output voltage value of the step-down circuit is... Where V Pout The voltage is the output voltage of the voltage regulator chip.

[0030] In the above-described embodiment, by reasonably setting the resistance values ​​R1 of the first resistor R1, R2 of the second resistor R2, and R3 of the third resistor R3, the states of the second resistor R2 and the third resistor R3 connected to the step-down circuit can be controlled as needed during the use of the step-down circuit, thereby obtaining multiple different output voltage values ​​of the step-down circuit and making the application scenarios of the step-down circuit more extensive.

[0031] like Figure 2 As shown, the step-down circuit based on the voltage regulator chip further includes a fourth resistor R4, a fifth resistor R5, and a second operational amplifier OP2. The first terminal of the fourth resistor R4 and the first power input terminal, second signal input terminal, and signal output terminal of the second operational amplifier OP2 are connected to the positive terminal of the power input terminal of the step-down circuit. The first signal input terminal of the second operational amplifier OP2 and the first terminal of the fifth resistor R5 are connected to the second terminal of the fourth resistor R4. The second terminal of the fifth resistor R5 and the second power input terminal of the second operational amplifier OP2 are connected to the negative terminal of the power input terminal and power output terminal of the step-down circuit. The resistance values ​​R4 and R5 of the fourth resistor R4 and the fifth resistor R5 satisfy the following:

[0032]

[0033] Among them, V Pin This refers to the input voltage value of the voltage regulator chip. Since the voltage regulator chip has a maximum input voltage limit, once the input voltage exceeds the rated voltage, the output voltage cannot be stabilized within the required range, and may even damage the device. By setting the fourth resistor R4, the fifth resistor R5, and the second operational amplifier OP2, the input voltage is reduced to the input voltage range that the voltage regulator chip can adapt to, allowing the buck circuit to adapt to a higher input voltage range.

[0034] Preferably, the resistance values ​​R4 of the fourth resistor R4 and R5 of the fifth resistor R5 satisfy the following:

[0035]

[0036] Among them, Min(V)Pin ) represents the minimum input voltage value within the operating range of the voltage regulator chip, Max(V) Pin ) represents the maximum input voltage value within the adaptability range of the voltage regulator chip, ΔV Pin This represents the maximum voltage fluctuation value at the input terminal of the voltage regulator chip in the buck circuit. In the above embodiment, by reasonably setting the resistance values ​​R4 of the fourth resistor and R5 of the fifth resistor, the input voltage of the voltage regulator chip in the buck circuit can always be within its suitable range, thereby ensuring the stability of the output voltage and preventing the input voltage of the voltage regulator chip from exceeding its maximum suitable voltage value due to voltage fluctuations, which would result in the inability to output the expected stable voltage value.

[0037] This invention proposes a step-down circuit based on a voltage regulator chip. The input terminal of the voltage regulator chip, the first power input terminal of the first operational amplifier, and the first terminal of the capacitor are connected to the positive terminal of the power input terminal. The ground terminal of the voltage regulator chip is connected to the first signal input terminal, the second signal input terminal, and the signal output terminal of the first operational amplifier. The output terminal of the voltage regulator chip is connected to the first terminal of the first resistor. The first signal input terminal of the first operational amplifier, the second terminal of the first resistor, the first terminal of the second resistor, and the first terminal of the first switch are connected to the positive terminal of the power output terminal. The first terminal of the second switch is connected to the second terminal of the first switch. The second terminal of the second resistor and the first terminal of the third resistor are connected to the second terminal of the second switch. The second power input terminal of the first operational amplifier, the second terminal of the capacitor, the second terminal of the third resistor, and the third terminal of the second switch are connected to the negative terminal of the power supply. This circuit can achieve multi-stage voltage output and has a wider range of applications.

[0038] It should be noted that, in this document, relational terms such as "first" and "second" are used merely 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 apparatus 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 apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0039] As described above, these embodiments of the present invention do not exhaustively cover all details, nor do they limit the invention to the specific embodiments described. Clearly, many modifications and variations can be made based on the above description. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to effectively utilize the invention and its modifications. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A step-down circuit based on a voltage regulator chip, characterized in that, The circuit includes a voltage regulator chip, a first operational amplifier, a capacitor, a first resistor, a second resistor, a third resistor, a first switch, and a second switch. The input terminal of the voltage regulator chip, the first power input terminal of the first operational amplifier, and the first terminal of the capacitor are connected to the positive terminal of the power input terminal of the buck circuit. The ground terminal of the voltage regulator chip is connected to the first signal input terminal, the second signal input terminal, and the signal output terminal of the first operational amplifier. The output terminal of the voltage regulator chip is connected to the first terminal of the first resistor. The first signal input terminal of the first operational amplifier, the second terminal of the first resistor, the first terminal of the second resistor, and the first terminal of the first switch are connected to the positive terminal of the power output terminal of the buck circuit. The first terminal of the second switch is connected to the second terminal of the first switch. The second terminal of the second resistor and the first terminal of the third resistor are connected to the second terminal of the second switch. The second power input terminal of the first operational amplifier, the second terminal of the capacitor, the second terminal of the third resistor, and the third terminal of the second switch are connected to the negative terminals of the power input and power output terminals of the buck circuit. The negative terminals of the power input and power output terminals of the buck circuit are grounded. The resistance value of the first resistor is... The resistance value of the second resistor is The resistance value of the third resistor is ; By controlling the switching states of the first and second switches to configure the connection states of the second and third resistors to the step-down circuit, the output voltage value of the step-down circuit is controlled. When both the first and second switches are closed, and the second switch is connected by connecting its first and third terminals, the output voltage value of the step-down circuit is... When both the first switch and the second switch are closed, and the second switch is connected by connecting its first and second terminals, the output voltage value of the step-down circuit is... When both the first switch and the second switch are in the open state, the output voltage value of the step-down circuit is... ,in The voltage is the output voltage of the voltage regulator chip.

2. The step-down circuit based on a voltage regulator chip according to claim 1, characterized in that, The resistance value of the first resistor The resistance value of the second resistor and the resistance value of the third resistor satisfy .

3. The step-down circuit based on a voltage regulator chip according to claim 1 or 2, characterized in that, The step-down circuit based on the voltage regulator chip further includes a fourth resistor, a fifth resistor, and a second operational amplifier. The first terminal of the fourth resistor, the first power input terminal, the second signal input terminal, and the signal output terminal of the second operational amplifier are connected to the positive terminal of the power input terminal of the step-down circuit. The first signal input terminal of the second operational amplifier and the first terminal of the fifth resistor are connected to the second terminal of the fourth resistor. The second terminal of the fifth resistor and the second power input terminal of the second operational amplifier are connected to the negative terminals of the power input and power output terminals of the step-down circuit. The resistance value of the fourth resistor is... and the resistance value of the fifth resistor satisfy: ； in, This refers to the input voltage value of the voltage regulator chip. This is the input voltage value of the step-down circuit.

4. The step-down circuit based on a voltage regulator chip according to claim 3, characterized in that, The resistance value of the fourth resistor and the resistance value of the fifth resistor satisfy: ； in, This refers to the minimum input voltage value within the operating range of the voltage regulator chip. This represents the maximum input voltage value within the range that the voltage regulator chip can adapt to. This represents the maximum voltage fluctuation value at the input terminal of the voltage regulator chip for the step-down circuit.

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