Lithium battery charging management circuit capable of being automatically turned off

Abstract

The utility model relates to the technical field of charging management, in particular to a lithium battery charging management circuit capable of being automatically turned off, which comprises a lithium battery BAT1, a charging management chip and an MCU (Microprogrammed Control Unit), and is characterized in that the lithium battery BAT1 is connected with the charging management chip, and meanwhile, the negative electrode of the lithium battery BAT1 is grounded; the charging management chip is provided with a charging port, and a charger inputs voltage charge by being connected with the charging port; the MCU is provided with a VCC (virtual channel connection) pin, a GPIO1 (general purpose input / output 1) pin and a GPIO2 pin; the lithium battery charging management circuit further comprises a PMOS tube Q1 and a triode Q2. A first diode D1, a capacitor C1 and a second resistor R2 are sequentially arranged between the charge + of the charging port and the base electrode of the triode Q2; the circuit system is provided with the power-on wake-up circuit and the charging wake-up circuit at the same time, and after the charger is plugged in, the MCU can automatically turn off the VCC of the circuit system according to set conditions or self conditions, so that the power consumption of the circuit system when the charger is plugged in is avoided, the waste of electric quantity is reduced, and the service life is prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of charging management, in particular to a lithium battery charging management circuit capable of self-shutdown. Background Art

[0002] In the razor industry that uses a single-cell lithium battery, the traditional practice is to merge the power-on wake-up circuit with the charging wake-up circuit. As long as the charger is plugged in, there is always VCC, the microcontroller is always in working condition, and VCC will also power other circuits, and the entire circuit cannot be powered off. Even when fully charged, the microcontroller and the system will not be powered off, resulting in a waste of electricity consumption, and there is a safety hazard of false operation if the power is not cut off. Utility Model Content

[0003] In view of the above-mentioned shortcomings of the prior art, the purpose of the utility model is to provide a lithium battery charging management circuit with self-shutdown, which is used to solve the problem in the prior art that the circuit system power-on wake-up and charging wake-up circuits are combined and cannot be powered off automatically.

[0004] In order to achieve the above-mentioned purpose and other related purposes, the utility model provides a self-shutdown lithium battery charging management circuit, including a lithium battery BAT1, a charging management chip and an MCU, wherein the lithium battery BAT1 is connected to the charging management chip and the negative electrode of the lithium battery BAT1 is grounded;

[0005] The charging management chip is provided with a charging port, and the charger charges the lithium battery BAT1 by connecting to the charging port and inputting a voltage charge;

[0006] The MCU has a VCC pin, a GPIO1 pin and a GPIO2 pin;

[0007] The lithium battery charging management circuit also includes a PMOS tube Q1 and a transistor Q2, and the G electrode of the PMOS tube Q1 is connected to the collector of the transistor Q2;

[0008] The S pole of the PMOS tube Q1 is connected to the positive pole of the lithium battery BAT1, and the D pole is connected to the MCU;

[0009] The base of the transistor Q2 is connected to the GPIO1 pin of the MCU, and the emitter is grounded;

[0010] A first diode D1, a capacitor C1, and a second resistor R2 are sequentially arranged between the charge+ of the charging port and the base of the transistor Q2. The input voltage charge+ turns on the transistor Q2 through the first diode D1, the capacitor C1, and the second resistor R2, and then turns on the PMOS tube Q1. The lithium battery BAT1 supplies power to the MCU through the PMOS tube Q1.

[0011] In an embodiment of the present invention, a second diode D2 is connected in parallel between the G electrode of the PMOS tube Q1 and the collector of the transistor Q2. A switch S1 is connected to the output end of the second diode D2, and the other end of the switch S1 is grounded.

[0012] In an embodiment of the present invention, a third diode D3 is connected to the GPIO2 pin of the MCU, and an output end of the third diode D3 is connected in parallel between the output end of the second diode D2 and the switch S1.

[0013] In an embodiment of the present invention, a first resistor R1 is connected in parallel between the S pole and the G pole of the PMOS transistor Q1 .

[0014] In an embodiment of the present invention, a third resistor R3 is connected in parallel between the base and the emitter of the transistor Q2 .

[0015] As described above, the self-shutdown lithium battery charging management circuit of the present invention has the following beneficial effects:

[0016] The utility model can form a power-on wake-up circuit for the circuit system through the first diode D1, the capacitor C1, the second resistor R2, the transistor Q2, and the PMOS tube Q1, and can form a charging wake-up circuit for the circuit system through the MCU, the transistor Q2, and the PMOS tube Q1. After the charger is plugged in, the MCU can automatically shut down the VCC of the circuit system according to the set conditions or according to its own situation, so as to avoid the circuit system from consuming power when the charger is plugged in, reduce the waste of power, and extend the service life; because the power supply system has been powered off, the risk of malfunction can be effectively reduced, and the safety of the circuit system is increased; and the MCU has higher controllability. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Shown is a circuit schematic diagram of a self-shutdown lithium battery charging management circuit disclosed in the utility model.

[0018] Component number description

[0019] Charging management chip 1; charging port 11. DETAILED DESCRIPTION

[0020] The following is a description of the implementation of the present invention by means of specific embodiments. People familiar with the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0021] See also Figure 1It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings in this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the conditions under which the utility model can be implemented. Therefore, they have no substantial technical significance. Any structural modification, change in proportion or adjustment of size should still fall within the scope of the technical content disclosed by the utility model without affecting the effects and purposes that can be achieved by the utility model.

[0022] See also Figure 1 The utility model provides a self-shutdown lithium battery charging management circuit, including a lithium battery BAT1, a charging management chip 1 and an MCU. The lithium battery BAT1 is connected to the charging management chip 1, and the negative electrode of the lithium battery BAT1 is grounded. The charging management chip 1 is provided with a charging port 11, and the charger charges the lithium battery BAT1 by connecting to the charging port 11 and inputting a voltage charge. The MCU has a VCC pin, a GPIO1 pin and a GPIO2 pin. The lithium battery charging management circuit also includes a PMOS tube Q1 and a transistor Q2. The G pole of the PMOS tube Q1 and the G pole of the transistor Q2 are connected. The collectors are connected; the S pole of the PMOS tube Q1 is connected to the positive pole of the lithium battery BAT1, and the D pole is connected to the MCU; the base of the transistor Q2 is connected to the GPIO1 pin of the MCU, and the emitter is grounded; the first diode D1, the capacitor C1, and the second resistor R2 are arranged in sequence between the charge+ of the charging port 11 and the base of the transistor Q2. When the charger is inserted, the input voltage charge+ passes through the first diode D1, the capacitor C1, and the second resistor R2 to turn on the transistor Q2, and then turn on the PMOS tube Q1. The lithium battery BAT1 supplies power to the MCU through the PMOS tube Q1. When the MCU is working, GPIO1 is set high, and the high level of the MCU keeps the transistor Q2 turned on all the time, thereby maintaining the on state of the circuit system. There is no need to use charge+ to maintain the on state of the circuit, and the system is maintained in the on state; when the circuit system VCC needs to be turned off, GPIO1 can be set low. When the charger is inserted, after waking up the MCU, the MCU can also shut down the system VCC and power off according to its own situation.

[0023] A second diode D2 is connected in parallel between the G pole of the PMOS tube Q1 and the collector of the transistor Q2, and a switch S1 is connected to the output end of the second diode D2, and the other end of the switch S1 is grounded; when the switch S1 is turned on, the purpose of self-shutdown of VCC of the MCU control circuit system is achieved; a third diode D3 is connected to the MCUGPIO2 pin, and the output end of the third diode D3 is connected in parallel between the output end of the second diode D2 and the switch S1, and the third diode D3 has a unidirectional conduction characteristic and is used for charge guidance.

[0024] A first resistor R1 is connected in parallel between the S pole and the G pole of the PMOS tube Q1. The first resistor R1 is a gate resistor that can provide a bias voltage for the field effect tube and act as a discharge resistor to protect the gate G and source S of the PMOS tube Q1.

[0025] A third resistor R3 is connected in parallel between the base and the emitter of the transistor Q2 . The third resistor R3 is an input resistor and plays a decisive role in the overall performance and stability of the transistor Q2 .

[0026] In summary, the utility model can form a power-on wake-up circuit for the circuit system through the first diode D1, the capacitor C1, the second resistor R2, the transistor Q2, and the PMOS tube Q1, and can form a charging wake-up circuit for the circuit system through the MCU, the transistor Q2, and the PMOS tube Q1. After plugging in the charger, the MCU can automatically shut down the VCC of the circuit system according to the set conditions or according to its own situation, so as to avoid the circuit system from consuming power when the charger is plugged in, reduce the waste of power, and extend the service life; because the power supply system has been powered off, it can effectively reduce the risk of malfunction and increase the safety of the circuit system; and the MCU has higher controllability. Therefore, the utility model effectively overcomes various shortcomings in the prior art and has a high industrial utilization value.

[0027] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the technology may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed in the present invention shall still be covered by the claims of the present invention.

Claims

1. A self-shutdown lithium battery charging management circuit, comprising a lithium battery BAT1, a charging management chip and an MCU, wherein the lithium battery BAT1 is connected to the charging management chip and the negative electrode of the lithium battery BAT1 is grounded; The charging management chip is provided with a charging port, and the charger charges the lithium battery BAT1 by connecting to the charging port and inputting a voltage charge; The MCU has a VCC pin, a GPIO1 pin and a GPIO2 pin; Features: The lithium battery charging management circuit also includes a PMOS tube Q1 and a transistor Q2, and the G electrode of the PMOS tube Q1 is connected to the collector of the transistor Q2; The S pole of the PMOS tube Q1 is connected to the positive pole of the lithium battery BAT1, and the D pole is connected to the MCU; The base of the transistor Q2 is connected to the GPIO1 pin of the MCU, and the emitter is grounded; A first diode D1, a capacitor C1, and a second resistor R2 are sequentially arranged between the charge+ of the charging port and the base of the transistor Q2. The input voltage charge+ turns on the transistor Q2 through the first diode D1, the capacitor C1, and the second resistor R2, and then turns on the PMOS tube Q1. The lithium battery BAT1 supplies power to the MCU through the PMOS tube Q1.

2. The self-shutdown lithium battery charging management circuit according to claim 1, characterized in that: A second diode D2 is connected in parallel between the G pole of the PMOS tube Q1 and the collector of the transistor Q2. A switch S1 is connected to the output end of the second diode D2, and the other end of the switch S1 is grounded.

3. The self-shutdown lithium battery charging management circuit according to claim 1, characterized in that: A third diode D3 is connected to the GPIO2 pin of the MCU, and an output end of the third diode D3 is connected in parallel between the output end of the second diode D2 and the switch S1.

4. The self-shutdown lithium battery charging management circuit according to claim 1, characterized in that: A first resistor R1 is connected in parallel between the S pole and the G pole of the PMOS tube Q1.

5. The self-shutdown lithium battery charging management circuit according to claim 1, characterized in that: A third resistor R3 is connected in parallel between the base and the emitter of the transistor Q2.

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