Power supply control circuit with wide voltage range and charging function

Abstract

The utility model provides a power supply control circuit with a charging function in a wide voltage range, and belongs to the field of power supply circuits. The power supply circuit comprises a power supply input interface, an overvoltage protection circuit, a buck-boost circuit, a charging management circuit and a battery power supply conversion circuit, and the input end of the overvoltage protection circuit is connected with the output end of the power supply input interface. The input end of the buck-boost circuit is respectively connected with the output end of the overvoltage protection circuit and the output end of the battery power supply conversion circuit, the output end of the buck-boost circuit is connected with the input end of the charging management circuit and outputs power supply voltage, and the output end of the charging management circuit charges a battery. And the output end of the battery is connected with the input end of the battery power supply conversion circuit. The beneficial effects of the utility model are that: support wide voltage input, can adapt to most power adapters on the market.

Description

Technical Field

[0001] The utility model relates to a power supply circuit, in particular to a power supply control circuit with a wide voltage range and a charging function. Background Art

[0002] Generally, portable sports products are powered by batteries, which directly output the power supply voltage to the products. Since the capacity of the battery fluctuates as the battery is discharged, the output voltage will fluctuate. In addition, when managing the battery's charge and discharge, it is necessary to provide a matching charging power supply according to the battery's working voltage, and there are certain requirements for the supply voltage of the charging power supply. It is not appropriate for the power supply voltage to be too high or too low. Utility Model Content

[0003] In order to solve the problems in the prior art, the utility model provides a power supply control circuit with a wide voltage range and a charging function.

[0004] The utility model discloses a power supply control circuit with a wide voltage range and a charging function, comprising a power input interface, an overvoltage protection circuit, a buck-boost circuit, a charging management circuit, and a battery power supply conversion circuit, wherein the input end of the overvoltage protection circuit is connected to the output end of the power input interface, the input end of the buck-boost circuit is respectively connected to the output end of the overvoltage protection circuit and the output end of the battery power supply conversion circuit, the output end of the buck-boost circuit is connected to the input end of the charging management circuit and outputs a power supply voltage, the output end of the charging management circuit charges the battery, and the output end of the battery is connected to the input end of the battery power supply conversion circuit.

[0005] Furthermore, it also includes a plurality of voltage-stabilized power supply branches, and the voltage-stabilized power supply branches are connected to the output end of the buck-boost circuit.

[0006] Furthermore, the overvoltage protection circuit includes a transistor Q1, a switch tube Q3, a resistor R44, a resistor R63, and a voltage-stabilizing diode D5, wherein one end of the resistor R44, the emitter of the transistor Q1, and the source of the switch tube Q3 are respectively connected to the output end of the power input interface, the other end of the resistor R44 is respectively connected to one end of the resistor R63 and the cathode of the voltage-stabilizing diode D5, the anode of the voltage-stabilizing diode D5 is grounded, the other end of the resistor R63 is connected to the base of the transistor Q1, the collector of the transistor Q1 is connected to the gate of the switch tube Q3, and then is grounded through the resistor R46, and the drain of the switch tube Q3 is the power output end.

[0007] Furthermore, the battery-powered conversion circuit includes a diode D1, a diode D3, a diode D7, a switch tube Q5, a polarity capacitor E1, a capacitor C35, a resistor R36, and a resistor R37, wherein the gate of the switch tube Q5 is respectively connected to the grounded resistor R37 and one end of the resistor R36, the other ground of the resistor R36 is connected to the negative electrode of the diode D1, the positive electrode of the diode D1 and the positive electrode of the diode D3 are connected to the output end of the overvoltage protection circuit, the drain of the switch tube Q5 and the positive electrode of the diode D7 are respectively connected to the output end of the battery, the source of the switch tube Q5 and the negative electrode of the diode D7 are connected to the negative electrode of the diode D3, for selecting battery power supply or overvoltage protection circuit power supply, the polarity capacitor E1 and the capacitor C35 are connected in parallel, one end is grounded, and the other end is connected to the input end of the buck-boost circuit.

[0008] Furthermore, the charging management circuit includes a charging chip U1, wherein the power input pin 4 of the charging chip U1 is connected to the output end of the buck-boost circuit, the enable pin 8 of the charging chip U1 is connected to the output end of the overvoltage protection circuit, and the charging pin 5 of the charging chip U1 is connected to the charging interface CN3 of the battery.

[0009] Furthermore, the power input interface supports a wide voltage range input, and the input voltage range of the power input interface is 3-12V.

[0010] Compared with the prior art, the utility model has the following beneficial effects: by setting a buck-boost circuit, both the battery and the external input power supply are powered by the buck-boost circuit, and the buck-boost circuit directly provides the power supply voltage, instead of the battery directly supplying power to the outside, so the stability of the power supply voltage can be ensured;

[0011] In addition, by setting up a step-up and step-down circuit and an overvoltage protection circuit, the power input interface of the utility model can support a wide voltage input, thereby being compatible with conventional power supplies whose output voltage does not exceed a certain value. By setting the maximum voltage value, it can adapt to most power adapters on the market, thereby realizing the power supply of the utility model and charging of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the solutions in the present invention or the prior art, a brief introduction is given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0013] Figure 1 This is the structural diagram of the utility model;

[0014] Figure 2This is a circuit diagram of an embodiment of the power input interface of the utility model;

[0015] Figure 3 This is a circuit schematic diagram of an embodiment of an overvoltage protection circuit of the utility model;

[0016] Figure 4 This is a circuit schematic diagram of an embodiment of a battery powered conversion circuit of the utility model;

[0017] Figure 5 This is a circuit schematic diagram of an embodiment of a buck-boost circuit of the utility model;

[0018] Figure 6 This is a circuit schematic diagram of an embodiment of a charging management circuit of the utility model;

[0019] Figure 7 This is a circuit diagram of an embodiment of a voltage-stabilized power supply branch of the utility model. DETAILED DESCRIPTION

[0020] Unless otherwise defined, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by technicians in the technical field of the present invention; the terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention; the terms "including" and "having" and any variations thereof in the specification and claims of the present invention and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of the present invention or the above-mentioned drawings are used to distinguish different objects, not to describe a specific order.

[0021] Reference to "embodiments" in the present invention means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it mutually exclusive, independent, or alternative to other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in the present invention may be combined with other embodiments.

[0022] In order to enable those skilled in the art to better understand the solution of the utility model, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the accompanying drawings.

[0023] like Figure 1As shown, the power supply control circuit with a wide voltage range and a charging function of the utility model comprises a power input interface, an overvoltage protection circuit, a buck-boost circuit, a charging management circuit, and a battery-powered conversion circuit, wherein the input end of the overvoltage protection circuit is connected to the output end of the power input interface, the input end of the buck-boost circuit is respectively connected to the output end of the overvoltage protection circuit and the output end of the battery-powered conversion circuit, the output end of the buck-boost circuit is connected to the input end of the charging management circuit and outputs a supply voltage, the output end of the charging management circuit charges the battery, and the output end of the battery is connected to the input end of the battery-powered conversion circuit.

[0024] In this example, several voltage-stabilized power supply branches can also be set up, and the voltage-stabilized power supply branches are used to output different power supply voltages to supply power to loads or internal chips. For example, if the chip requires 3.3V or 1.2V power supply, two parallel voltage-stabilized power supply branches can be set up for power supply, and can also be set up in a series mode with step-by-step voltage reduction.

[0025] The utility model sets a buck-boost circuit, and the battery and the external input power supply are both powered by the buck-boost circuit. The buck-boost circuit directly provides the power supply voltage, instead of the battery directly supplying power to the outside, which can ensure the stability of the power supply voltage. In addition, the battery supply voltage in this example is 3.7V, and the output voltage Vo of the entire circuit can be set to be much higher than the battery voltage, such as 4.8V. The utility model can achieve a power supply much higher than the battery voltage, and is not affected by the battery capacity. When the battery is as low as 3V, the buck-boost circuit can still provide a stable output voltage.

[0026] By setting up a step-up and step-down circuit and an overvoltage protection circuit, the power input interface of the utility model can support a wide voltage input, thereby being compatible with conventional power supplies with an output voltage of 3-12V. By setting the maximum voltage value, when it exceeds 12V, the overvoltage protection circuit will take effect and automatically cut off the external power supply, thereby protecting the product while being compatible with most power adapters on the market to realize power supply to the utility model and charging of the battery.

[0027] like Figure 7 As shown, the voltage-stabilizing power supply branch of this example stabilizes the voltage Vo output by the buck-boost circuit to 3.3V required for the operation of other control circuits. This example uses an LDO control chip to convert the output Vo of the buck-boost circuit into a 3.3V power supply that can be used by other control circuits. Of course, other voltage-stabilizing circuits such as voltage regulators can also be used.

[0028] like Figure 2 As described above, the power input interface CN1 of this example can connect a 3-12V DC power supply to the control circuit, and the external power supply is connected to the control circuit through the power input interface CN1 to realize external power supply and battery charging.

[0029] like Figure 3 As shown, the overvoltage protection circuit of this example provides overvoltage protection for the entire circuit, and the overvoltage protection circuit includes a transistor Q1, a switch tube Q3, a resistor R44, a resistor R63, and a voltage-stabilizing diode D5, wherein one end of the resistor R44, the emitter of the transistor Q1, and the source of the switch tube Q3 are respectively connected to the output end of the power input interface, the other end of the resistor R44 is respectively connected to one end of the resistor R63 and the cathode of the voltage-stabilizing diode D5, the anode of the voltage-stabilizing diode D5 is grounded, the other end of the resistor R63 is connected to the base of the transistor Q1, the collector of the transistor Q1 is connected to the gate of the switch tube Q3, and then is grounded through the resistor R46, and the drain of the switch tube Q3 is the power output end.

[0030] When it is detected that the power supply voltage is greater than 12VDC, the base of the transistor Q1 is turned on at a high level, and then the gate of the switch tube Q3 is pulled down, the switch tube Q3 is disconnected, and the external power supply of the control circuit is automatically cut off, thereby isolating the external power supply from the internal circuit.

[0031] like Figure 4 As shown, the battery-powered conversion circuit of this example includes a diode D1, a diode D3, a diode D7, a switch tube Q5, a polarity capacitor E1, a capacitor C35, a resistor R36, and a resistor R37, wherein the gate of the switch tube Q5 is respectively connected to the grounded resistor R37 and one end of the resistor R36, the other ground of the resistor R36 is connected to the cathode of the diode D1, the anode of the diode D1 and the anode of the diode D3 are connected to the output end of the overvoltage protection circuit, the drain of the switch tube Q5 and the anode of the diode D7 are respectively connected to the output end of the battery, the source of the switch tube Q5 and the cathode of the diode D7 are connected to the cathode of the diode D3, for selecting battery power supply or overvoltage protection circuit power supply, the polarity capacitor E1 and the capacitor C35 are connected in parallel, one end is grounded, and the other end is connected to the input end of the buck-boost circuit.

[0032] When the external power supply is disconnected, there is no voltage input at the VBUS_io terminal, so the gate of the switch tube Q5 is at a low level, the switch tube Q5 is turned on, and the battery terminal BAT+ is discharged, realizing the automatic switching from the external power supply to the battery to power the buck-boost circuit. However, at this time, due to the setting of the diode D7, the battery will not be charged. Through the setting of the battery-powered conversion circuit of the utility model, it is ensured that the control circuit uses the battery to provide a stable voltage without an external power supply, and when the battery is as low as 3V, the buck-boost circuit can still provide a stable output voltage.

[0033] like Figure 5As shown, the step-up / step-down circuit in this example is a voltage stabilizing chip U3, which can control the power supply of 3-12VDC to a stable output voltage Vo, for example, the voltage value of Vo is 4.8VDC.

[0034] like Figure 6 As shown, the charging management circuit of this example uses the buck-boost circuit output voltage Vo to automatically charge the 3.7V battery through battery charging management, and the charging condition is that the external power supply must be valid to charge.

[0035] The charging management circuit of this example includes a charging chip U1, wherein the power input pin 4 of the charging chip U1 is connected to the output voltage Vo of the buck-boost circuit, the enable pin 8 of the charging chip U1 is connected to the output voltage VBUS_io of the overvoltage protection circuit, and the charging pin 5 of the charging chip U1 is connected to the charging interface CN3 of the battery. In addition, an indicator light RL1 is provided to indicate the charging status when charging.

[0036] When the overvoltage protection circuit output voltage VBUS_io is charged, the charging chip U1 works and outputs voltage to charge the 3.7V lithium battery through the interface CN3. This charging management circuit can efficiently charge and isolate the battery and monitor the charging and discharging status of the battery.

[0037] As can be seen from the above, the utility model is suitable for portable products using 3.7V batteries and can be applied to charging power supply voltage range of 3 to 12VDC, so that conventional power supply with output voltage not exceeding 12VDC can realize normal charging of the utility model, the circuit is simple to use and has strong compatibility.

[0038] The specific implementation methods described above are preferred implementation methods of the present utility model, and are not intended to limit the specific implementation scope of the present utility model. The scope of the present utility model includes but is not limited to the specific implementation methods. All equivalent changes made in accordance with the present utility model are within the protection scope of the present utility model.

Claims

1. A power supply control circuit with a wide voltage range and a charging function, characterized in that: It includes a power input interface, an overvoltage protection circuit, a buck-boost circuit, a charging management circuit, and a battery-powered conversion circuit, wherein the input end of the overvoltage protection circuit is connected to the output end of the power input interface, the input end of the buck-boost circuit is respectively connected to the output end of the overvoltage protection circuit and the output end of the battery-powered conversion circuit, the output end of the buck-boost circuit is connected to the input end of the charging management circuit and outputs a supply voltage, the output end of the charging management circuit charges the battery, and the output end of the battery is connected to the input end of the battery-powered conversion circuit.

2. The power supply control circuit with wide voltage range and charging function according to claim 1, characterized in that: It also includes a plurality of voltage-stabilizing power supply branches, which are connected to the output end of the buck-boost circuit.

3. The power supply control circuit with wide voltage range and charging function according to claim 1 or 2, characterized in that: The overvoltage protection circuit includes a transistor Q1, a switch tube Q3, a resistor R44, a resistor R63, and a voltage-stabilizing diode D5, wherein one end of the resistor R44, the emitter of the transistor Q1, and the source of the switch tube Q3 are respectively connected to the output end of the power input interface, the other end of the resistor R44 is respectively connected to one end of the resistor R63 and the cathode of the voltage-stabilizing diode D5, the anode of the voltage-stabilizing diode D5 is grounded, the other end of the resistor R63 is connected to the base of the transistor Q1, the collector of the transistor Q1 is connected to the gate of the switch tube Q3, and then is grounded through the resistor R46, and the drain of the switch tube Q3 is the power output end.

4. The power supply control circuit with wide voltage range and charging function according to claim 1 or 2, characterized in that: The battery-powered conversion circuit includes a diode D1, a diode D3, a diode D7, a switch tube Q5, a polarity capacitor E1, a capacitor C35, a resistor R36, and a resistor R37, wherein the gate of the switch tube Q5 is respectively connected to the grounded resistor R37 and one end of the resistor R36, the other ground of the resistor R36 is connected to the cathode of the diode D1, the anode of the diode D1 and the anode of the diode D3 are connected to the output end of the overvoltage protection circuit, the drain of the switch tube Q5 and the anode of the diode D7 are respectively connected to the output end of the battery, the source of the switch tube Q5 and the cathode of the diode D7 are connected to the cathode of the diode D3, and are used to select battery power supply or overvoltage protection circuit power supply, the polarity capacitor E1 and the capacitor C35 are connected in parallel, one end is grounded, and the other end is connected to the input end of the buck-boost circuit.

5. The power supply control circuit with wide voltage range and charging function according to claim 1 or 2, characterized in that: The charging management circuit includes a charging chip U1, wherein the power input pin 4 of the charging chip U1 is connected to the output end of the buck-boost circuit, the enable pin 8 of the charging chip U1 is connected to the output end of the overvoltage protection circuit, and the charging pin 5 of the charging chip U1 is connected to the charging interface CN3 of the battery.

6. The power supply control circuit with wide voltage range and charging function according to claim 1 or 2, characterized in that: The power input interface supports a wide voltage range input, and the input voltage range of the power input interface is 3-12V.

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