Double-voltage output BUCK circuit

Abstract

The utility model discloses a double voltage output BUCK circuit, which comprises a BUCK step-down circuit, a control chip U1 and a control chip U2, the BUCK step-down circuit is connected with a direct current power supply, the BUCK step-down circuit comprises an inductance energy storage circuit composed of a field effect transistor Q1, a field effect transistor Q2, an inductor L1 and a resistor RL, and the inductance energy storage circuit is connected with the control chip U1 and the control chip U2. The inductor discharging circuit is composed of an inductor L1, a resistor RL and a field effect transistor Q4, the control chip U2 is connected with the field effect transistor Q1 through a field effect transistor Q3, the control chip U2 is connected with the control chip U1 through a field effect transistor Q5, the control chip U1 is connected with the BUCK voltage reduction circuit, and the BUCK voltage reduction circuit is connected with the inductor discharging circuit. The control chip U2 enables the field effect transistor Q3 to be conducted by sending out a DCEN signal so as to enable the field effect transistor Q1 to be conducted, and the control chip U2 controls the field effect transistor Q5 to be conducted by sending out a DCFB signal. By short pressing and long pressing of the SW1 switch, signals are sent out through the main control MCU, and the 12V voltage and the 24V voltage can be switched and output mutually.

Description

Technical Field

[0001] The utility model relates to the technical field of BUCK step-down circuits, in particular to a BUCK circuit with dual voltage outputs. Background Art

[0002] In DC load applications, such as DC12V vacuum cleaners, air pumps, car refrigerators, 24V household DC equipment, DC emergency lights, DC air conditioners, refrigerators and other equipment, the traditional BUCK step-down circuit has only one way or one voltage output, which can only be used for DC loads of the same voltage. Figure 1 As shown, in practical applications, it is relatively simple and cannot meet the application scenarios with more voltages or higher requirements. Therefore, a BUCK circuit with dual voltage output is proposed. Utility Model Content

[0003] In order to overcome the shortcomings of the prior art, the utility model provides a BUCK circuit with dual voltage output. In practical applications, it can provide 12V or 24V DC load output. This feature is more convenient in use, saves one BUCK main power circuit, saves the application cost of each power device and each digital analog device in the circuit, and greatly improves the utilization rate of the circuit.

[0004] In order to solve the above technical problems, the utility model provides the following technical solutions: a BUCK circuit with dual voltage output, including a BUCK buck circuit and a control chip U1 and a control chip U2, the BUCK buck circuit is connected to a DC power supply, the BUCK buck circuit includes an inductor energy storage circuit composed of a field effect transistor Q1, a field effect transistor Q2, an inductor L1, and a resistor RL, and an inductor discharge circuit composed of an inductor L1, a resistor RL, and a field effect transistor Q4, the control chip U2 is connected to the field effect transistor Q1 through a field effect transistor Q3, the control chip U2 is connected to the control chip U1 through a field effect transistor Q5, the control chip U1 is connected to the BUCK buck circuit, the control chip U2 turns on the field effect transistor Q3 by sending a DC_EN signal, thereby turning on the field effect transistor Q1, the control chip U2 controls the field effect transistor Q5 to turn on by sending a DC_FB signal, changes the voltage feedback network of the control chip U1, and realizes 12V and 24V switching output.

[0005] As a preferred technical solution of the utility model, the control chip U2 has a SW1 switch. The control chip U2 controls the DC_EN signal to be sent by short pressing the SW1 switch for 1 second, controls the field effect transistor Q3 to be turned on, and realizes a 12V DC voltage output.

[0006] As a preferred technical solution of the utility model, the control chip U2 controls the DC_EN and DC_FB signals to be sent simultaneously by pressing and holding the SW1 switch for 5 seconds, controls the field effect transistor Q3 and the field effect transistor Q5 to be turned on simultaneously, and switches to a 24V DC output.

[0007] As a preferred technical solution of the utility model, the DC_EN completes the two steps of turning off / on the field effect transistor Q3 within 5 seconds, including the field effect transistor Q3 turning off operation in the first 3 seconds and the field effect transistor Q3 turning on operation in the last 2 seconds.

[0008] Compared with the prior art, the utility model can achieve the following beneficial effects:

[0009] The utility model circuit utilizes the short press and long press of the SW1 switch in the same BUCK circuit, and sends a signal through the main control MCU, so that the 12V and 24V voltages can be switched between output without interfering with each other. In practical applications, 12V or 24V DC load output can be provided, which is more convenient in use, saves one BUCK main power circuit, saves the application cost of each power device and each digital analog device in the circuit, and greatly improves the utilization rate of the circuit.

[0010] Additional aspects and advantages of the present invention will be given in part in the following description, and in part will become apparent from the following description, or will be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0012] Figure 1 It is a prior art circuit diagram in the background technology;

[0013] Figure 2 It is a circuit diagram of the dual voltage BUCK circuit of the utility model;

[0014] Figure 3 It is a schematic block diagram of the dual voltage BUCK circuit of the utility model. DETAILED DESCRIPTION

[0015] In order to make the technical means, creative features, purpose and efficacy of the utility model easy to understand, the utility model is further described below in conjunction with specific embodiments, but the following embodiments are only preferred embodiments of the utility model, not all. Based on the embodiments in the implementation mode, other embodiments obtained by those skilled in the art without creative work are all within the scope of protection of the utility model. The experimental methods in the following embodiments are conventional methods unless otherwise specified, and the materials, reagents, etc. used in the following embodiments are all commercially available unless otherwise specified.

[0016] See also Figures 2-3 As shown, the utility model provides a BUCK circuit with dual voltage output, including a BUCK buck circuit and a control chip U1 and a control chip U2. The BUCK buck circuit is connected to a DC power supply. The BUCK buck circuit includes an inductor energy storage circuit composed of a field effect transistor Q1, a field effect transistor Q2, an inductor L1, and a resistor RL, and an inductor discharge circuit composed of an inductor L1, a resistor RL, and a field effect transistor Q4. The control chip U2 is connected to the field effect transistor Q1 through a field effect transistor Q3, and the control chip U2 is connected to the control chip U1 through a field effect transistor Q5. The control chip U1 is connected to the BUCK buck circuit. The control chip U2 turns on the field effect transistor Q3 by sending a DC_EN signal, thereby turning on the field effect transistor Q1. The control chip U2 controls the field effect transistor Q5 to turn on by sending a DC_FB signal, thereby changing the voltage feedback network of the control chip U1 to achieve 12V and 24V switching output.

[0017] Preferably, the control chip U2 has a SW1 switch, and the control chip U2 controls the DC_EN signal to be sent by short pressing the SW1 switch for 1 second, controls the field effect transistor Q3 to be turned on, and realizes a 12V DC voltage output. The control chip U2 controls the DC_EN and DC_FB signals to be sent simultaneously by long pressing the SW1 switch for 5 seconds, controls the field effect transistor Q3 and the field effect transistor Q5 to be turned on simultaneously, and realizes switching to a 24V DC output.

[0018] Preferably, in order to ensure reliability during switching, the DC_EN completes the two steps of turning off / on the field effect transistor Q3 within 5 seconds, including the field effect transistor Q3 turning off operation in the first 3 seconds and the field effect transistor Q3 turning on operation in the last 2 seconds, which is more conducive to the two voltages not interfering with each other when switching outputs. Example

[0019] The utility model BUCK step-down circuit can realize the mutual switching output between 12V and 24V voltage. By pressing the SW1 button for 1S, 12V DC voltage output is realized. By pressing the SW1 button for 5S, it is switched to 24V DC output. The sequence is SW1 (1S) → 12VDC → SW1 (5S) → 24VDC → SW1 (5S) → 12VDC.

[0020] The working principle of the BUCK buck circuit of the utility model is: the main control MCU sends a DC_EN signal, the field effect transistor Q1 and the field effect transistor Q3 are turned on, the main power circuit starts to work, and the 12VDC output is realized through the main power BUCK buck circuit module. The circuit working path includes the inductor energy storage path: BAT+→field effect transistor Q1→field effect transistor Q2→inductor L1→resistor RL→BAT-, and the inductor discharge path: inductor L1→resistor RL→field effect transistor Q4→inductor L1, so as to complete the 12V DC buck.

[0021] When the SW1 button is pressed for 5 seconds, the main control MCU of the control chip U2 sends out DC_EN and DC_FB signals to achieve 24VDC output. In order to ensure the reliability during switching, DC_EN will complete the two steps of turning off / on the field effect transistor Q3 within 5 seconds, including 3S off and 2S on, which is more conducive to the two voltages not interfering with each other when switching outputs. The circuit working path is BAT+→field effect transistor Q1→field effect transistor Q2→inductor L1→resistor RL→BAT- (inductor energy storage path), inductor L1→resistor RL→field effect transistor Q4→inductor L1 (discharge path), completing 24V DC step-down.

[0022] The utility model circuit mainly uses the short and long press of the SW1 switch in the same BUCK circuit to send a signal through the main control MCU, which can realize the switching output of 12V and 24V voltages without interfering with each other. In practical applications, 12V or 24V DC load output can be provided. This feature is more convenient in use, eliminating a BUCK main power circuit, saving the application cost of each power device and each digital analog device in the circuit, and greatly improving the utilization rate of the circuit.

[0023] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0024] The above shows and describes the basic principle, main features and advantages of the utility model. Those skilled in the art should understand that the utility model is not limited by the above embodiments. The above embodiments and descriptions are only preferred examples of the utility model and are not used to limit the utility model. Without departing from the spirit and scope of the utility model, the utility model may have various changes and improvements, which fall within the scope of the utility model to be protected. The scope of protection of the utility model is defined by the attached claims and their equivalents.

Claims

1. A BUCK circuit with dual voltage output, characterized in that: The invention comprises a BUCK buck circuit and a control chip U1 and a control chip U2. The BUCK buck circuit is connected to a DC power supply. The BUCK buck circuit comprises an inductor energy storage circuit composed of a field effect transistor Q1, a field effect transistor Q2, an inductor L1 and a resistor RL, and an inductor discharge circuit composed of an inductor L1, a resistor RL and a field effect transistor Q4. The control chip U2 is connected to the field effect transistor Q1 through a field effect transistor Q3. The control chip U2 is connected to the control chip U1 through a field effect transistor Q5. The control chip U1 is connected to the BUCK buck circuit. The control chip U2 turns on the field effect transistor Q3 by sending a DC_EN signal, thereby turning on the field effect transistor Q1. The control chip U2 controls the field effect transistor Q5 to turn on by sending a DC_FB signal, thereby changing the voltage feedback network of the control chip U1 and realizing 12V and 24V switching output.

2. The BUCK circuit with dual voltage output according to claim 1, characterized in that: The control chip U2 has a SW1 switch. The control chip U2 controls the DC_EN signal to be sent out by short pressing the SW1 switch for 1 second, thereby controlling the field effect transistor Q3 to be turned on.

3. The BUCK circuit with dual voltage output according to claim 2, characterized in that: The control chip U2 controls the DC_EN and DC_FB signals to be sent out simultaneously by pressing the SW1 switch for 5 seconds, and controls the field effect transistor Q3 and the field effect transistor Q5 to be turned on simultaneously.

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