Step-down circuit

Abstract

The utility model discloses a step-down circuit, which comprises a switch module, a first diode, an inductor, a first resistor, a second resistor, a third resistor, a fourth resistor, a precise voltage stabilizing source, a first capacitor, a second capacitor and a fourth capacitor. According to the utility model, the input voltage can be 5V or 12V, the switch module comprises a switch device, when the switch device is closed, the input current stores energy in the inductor, and when the switch device is disconnected, the electric energy in the inductor is released and is supplied to the load through the follow current of the first diode; the output voltage is jointly divided by the first resistor, the second resistor and the precise voltage stabilizing source and then is provided to the feedback end of the switch module so as to control the on-off duration of the switch; the cathode and the reference end of the precise voltage stabilizing source are also connected to the input pin of the switch module through a second resistor, so that the voltage is further stabilized; the low-voltage constant-voltage power supply can provide stabilized voltage output as low as 120mV, the output current can be 2-2.5 A, and the low-voltage constant-voltage power supply can be applied to semiconductor refrigeration and can realize low-voltage, large-current and high constant-voltage stability.

Description

Technical Field

[0001] The utility model belongs to the field of electronic technology, and particularly relates to a step-down circuit. Background Art

[0002] Semiconductor refrigeration is a technology that uses the thermoelectric effect to achieve refrigeration. It applies a direct current between two different materials, causing heat to transfer from one material to the other, thereby producing a cooling effect on one surface.

[0003] The efficiency of semiconductor refrigeration is mainly related to the current. The larger the current, the stronger the refrigeration. Considering power consumption, if it is not desired that the device consumes too much power under large current, the voltage needs to be reduced as much as possible. In addition, some semiconductor refrigerators can only withstand a relatively low voltage. Once overvoltage occurs, the device is easily broken down and damaged. The application of semiconductor refrigeration poses new requirements for the power supply, requiring low voltage, large current, and high constant voltage stability. The existing DC voltage sources are still difficult to meet the above requirements.

[0004] In view of this, a new step-down circuit needs to be proposed to solve the above problems. Summary of the Utility Model

[0005] To solve the problems commonly existing in the prior art, the utility model proposes a step-down circuit that can be applied to semiconductor refrigeration and can achieve low voltage, large current, and high constant voltage stability.

[0006] The technical solution adopted by the utility model is as follows:

[0007] The utility model proposes a step-down circuit, which includes a switch module, a first diode, an inductor, a first resistor, a second resistor, a third resistor, a fourth resistor, a precision voltage stabilizer, a first capacitor, a second capacitor, and a fourth capacitor. The positive end of the input port is connected to the first end of the second resistor, the input pin, and the enable pin of the switch module. The switch pin of the switch module is connected to the cathode of the first diode and the first end of the inductor. A first capacitor is connected in parallel between the switch pin and the bootstrap pin of the switch module. The second end of the inductor is connected to the positive end of the output port and the first end of the first resistor. The second end of the first resistor is connected to the feedback pin of the switch module and the first end of the third resistor. The second end of the third resistor is connected to the second end of the second resistor, the cathode, and the reference end of the precision voltage stabilizer. The negative end of the input port, the ground pin of the switch module, the anode of the first diode, the anode of the precision voltage stabilizer, and the negative end of the output port are all grounded. The second capacitor is connected in parallel between the positive end and the negative end of the input port. The fourth capacitor and the fourth resistor are both connected in parallel between the positive end and the negative end of the output port.

[0008] Further, it further includes a third capacitor, which is connected in parallel between the positive end and the negative end of the input port.

[0009] Furthermore, a fifth capacitor and a sixth capacitor are included, and both the fifth capacitor and the sixth capacitor are connected in parallel between the positive end and the negative end of the output port.

[0010] The beneficial effects of the utility model are:

[0011] The input voltage of the utility model can be 5V or 12V. The switch module includes a switching device. When the switching device is closed, the input current stores energy in the inductor. When the switching device is disconnected, the electrical energy in the inductor is released and provided to the load through the first diode. The output voltage is divided by the first resistor, the second resistor and the precision voltage-stabilizing source and provided to the feedback end of the switch module to control the on-off duration of the switch. The cathode and reference end of the precision voltage-stabilizing source are also connected to the input pin of the switch module through the second resistor to further stabilize the voltage. Under the joint action of all devices, the embodiment of the utility model can provide a regulated voltage output as low as 120mV, and the output current can be 2~2.5A. The utility model can be applied to semiconductor refrigeration, and can achieve low voltage, large current and high constant voltage stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 The utility model is a schematic diagram of the circuit principle of a step-down circuit embodiment. DETAILED DESCRIPTION

[0013] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0014] The terms "first", "second" and "third" in this application are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number or order of the indicated technical features. All directional indications in the embodiments of this application (such as up, down, left, right, front, back...) are only used to explain the relative position relationship or movement between the components in a certain specific posture (as shown in the accompanying drawings); it should be noted that when a component is referred to as "fixed to", "set to" or "connected to" another component, it can be directly on the other component or there can be a central component. When a component is considered to be "connected" to another component, it can be directly connected to the other component, or there may be one or more central components in between. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only implementation method.

[0015] As Figure 1 shown, to solve the problems commonly existing in the prior art, the present utility model proposes a step-down circuit, which can be applied to semiconductor refrigeration and can achieve low voltage, large current and relatively high constant voltage stability.

[0016] Specifically, referring to Figure 1 , an embodiment of a step-down circuit includes a switch module U1, a first diode D1, an inductor L1, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a precision voltage regulator D2, a first capacitor C1, a second capacitor C2 and a fourth capacitor C4. The positive terminal of the input port J1 is connected to the first end of the second resistor R2, the input pin VIN and the enable pin EN of the switch module U1. The switch pin SW of the switch module U1 is connected to the cathode of the first diode D1 and the first end of the inductor L1. A first capacitor C1 is connected in parallel between the switch pin SW and the bootstrap pin VBST of the switch module U1. The second end of the inductor L1 is connected to the positive terminal of the output port J2 and the first end of the first resistor R1. The second end of the first resistor R1 is connected to the feedback pin VFB of the switch module U1 and the first end of the third resistor R3. The second end of the third resistor R3 is connected to the second end of the second resistor R2, the cathode and the reference terminal of the precision voltage regulator D2. The negative terminal of the input port J1, the ground pin GND of the switch module U1, the anode of the first diode D1, the anode of the precision voltage regulator D2 and the negative terminal of the output port J2 are all grounded. The second capacitor C2 is connected in parallel between the positive and negative terminals of the input port J1. The fourth capacitor C4 and the fourth resistor R4 are both connected in parallel between the positive and negative terminals of the output port J2.

[0017] In a specific implementation, the input voltage connected to the input port J1 can be 5V or 12V. The switch module U1 can be a synchronous step-down voltage regulator chip, and the model can be TPS564201, or other chips with similar functions. The precision voltage regulator D2 can be a precision voltage regulator of the TL431 model, or other devices with similar functions.

[0018] The switch module U1 implemented by the present utility model includes a switching device. When the switching device is closed, the input current stores energy in the inductor L1. When the switching device is opened, the electrical energy in the inductor L1 is released, and the current is continued through the first diode D1 to supply the load. The output voltage is divided by the first resistor R1, the second resistor R2 and the precision voltage regulator D2 and then provided to the feedback terminal of the switch module U1 to control the on and off duration of the switch. The cathode and the reference terminal of the precision voltage regulator D2 are also connected to the input pin VIN of the switch module U1 through the second resistor R2, thereby further stabilizing the voltage. Under the combined action of all devices, the embodiment of the present utility model can provide a regulated voltage output as low as 120mV, and the output current can be 2 - 2.5A.

[0019] In some embodiments, the buck circuit further includes a third capacitor C3, and the third capacitor C3 is connected in parallel between the positive terminal and the negative terminal of the input port J1. The application of the third capacitor C3 can further filter out input interference and stabilize the voltage.

[0020] In some embodiments, the buck circuit further includes a fifth capacitor C5 and a sixth capacitor C6, and both the fifth capacitor C5 and the sixth capacitor C6 are connected in parallel between the positive terminal and the negative terminal of the output port J2.

[0021] The application of the fifth capacitor C5 and the sixth capacitor C6 can further stabilize the voltage.

[0022] The present utility model is not limited to the above optional embodiments, and anyone can obtain other various forms of products under the inspiration of the present utility model. However, no matter what changes are made in its shape or structure, as long as the technical solutions fall within the scope defined by the claims of the present utility model, they are all within the protection scope of the present utility model.

Claims

1. A step-down circuit, characterized in that It includes a switching module (U1), a first diode (D1), an inductor (L1), a first resistor (R1), a second resistor (R2), a third resistor (R3), a fourth resistor (R4), a precision voltage regulator (D2), a first capacitor (C1), a second capacitor (C2), and a fourth capacitor (C4). The positive terminal of the input port (J1) is connected to the first terminal of the second resistor (R2), the input pin (VIN) and the enable pin (EN) of the switching module (U1). The switching pin (SW) of the switching module (U1) is connected to the cathode of the first diode (D1) and the first terminal of the inductor (L1). A first capacitor (C1) is connected in parallel between the switching pin (SW) and the bootstrap pin (VBST) of the switching module (U1). The second terminal of the inductor (L1) is connected to the positive terminal of the output port (J2) and the first terminal of the first resistor (R1). The second terminal of the first resistor (R1) is connected to the feedback pin (VFB) of the switching module (U1) and the first terminal of the third resistor (R3). The second terminal of the third resistor (R3) is connected to the second terminal of the second resistor (R2), the cathode and the reference terminal of the precision voltage regulator (D2). The negative terminal of the input port (J1), the ground pin (GND) of the switching module (U1), the anode of the first diode (D1), the anode of the precision voltage regulator (D2), and the negative terminal of the output port (J2) are all grounded. The second capacitor (C2) is connected in parallel between the positive and negative terminals of the input port (J1). The fourth capacitor (C4) and the fourth resistor (R4) are both connected in parallel between the positive and negative terminals of the output port (J2).

2. The step-down circuit according to claim 1, wherein It further includes a third capacitor (C3), and the third capacitor (C3) is connected in parallel between the positive and negative terminals of the input port (J1).

3. The step-down circuit according to claim 1, wherein It further includes a fifth capacitor (C5) and a sixth capacitor (C6), and the fifth capacitor (C5) and the sixth capacitor (C6) are both connected in parallel between the positive and negative terminals of the output port (J2).

Images