A control circuit for a battery charging temperature protection chip

Abstract

The present invention relates to the technical field of electronic circuits, and discloses a control circuit for a battery charging temperature protection chip, which includes several MOS transistors, several resistors, a flip-flop, a capacitor, and a connector. The source of the MOS transistor Q1 among the several MOS transistors is connected to the drain of the MOS transistor Q3 and one end of the resistor R4, and the drain is connected to the third pin of the flip-flop U1 and one end of the resistor R14. The gate of the MOS transistor Q2 is connected to the gate of the MOS transistor Q3 and the drain of the MOS transistor Q7, the source is connected to the source of the MOS transistor Q3, one end of the capacitor C1, and one end of the resistor R13, and the drain is connected to one end of the resistor R3. The first pin of the flip-flop U1 is connected to one end of the resistor R6, the second pin is connected to the sixth pin, and the fourth pin, the resistor R3, and the other end of the resistor R6 are connected to the power supply. The source of the MOS transistor Q7 is connected to the P1 end of the connector. The other ends of the resistor R4, the resistor R13, the resistor R14, and the capacitor C1 are grounded.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic circuits, and particularly relates to a control circuit for a battery charging temperature protection chip. Background Art

[0002] In order to shorten the charging time and protect the battery life, when the battery is in a low temperature state and starts charging, it is often necessary to preheat the battery. During the preheating period, the charging current is maintained at a relatively low amplitude. During the preheating period, the battery temperature will gradually rise. When the battery temperature is within the appropriate temperature range, the charging current of the battery will be adjusted step by step based on the real-time temperature of the battery. However, the instantaneous fluctuation of the step change of the charging current will cause the internal reaction of the battery to be unbalanced, which will in turn cause the temperature of the battery to rise suddenly. Therefore, a control circuit for a battery charging temperature protection chip is proposed, which can make the charging current of the battery rise smoothly based on the current amplitude allowed for charging in the low temperature range after the battery temperature changes from the low temperature range to the appropriate temperature range, and when the battery temperature jumps back and forth between the two temperature ranges due to environmental factors, limit the charging current of the battery and wait until the battery temperature stabilizes in the appropriate temperature range and then rise smoothly again. Summary of the Invention

[0003] In view of the above technical problems, the object of the present invention is to provide a control circuit for a battery charging temperature protection chip, which includes several MOS transistors, several resistors, a flip-flop, a capacitor, and a connector. The source of the MOS transistor Q1 among the several MOS transistors is connected to the drain of the MOS transistor Q3 and one end of the resistor R4, and the drain is connected to the third pin of the flip-flop U1 and one end of the resistor R14; the gate of the MOS transistor Q2 is connected to the gate of the MOS transistor Q3 and the drain of the MOS transistor Q7, the source is connected to the source of the MOS transistor Q3, one end of the capacitor C1, and one end of the resistor R13, and the drain is connected to one end of the resistor R3; the first pin of the flip-flop U1 is connected to one end of the resistor R6, the second pin is connected to the sixth pin, and the fourth pin, the resistor R3, and the other end of the resistor R6 are connected to the power supply; the source of the MOS transistor Q7 is connected to the P1 end of the connector; the other ends of the resistor R4, the resistor R13, the resistor R14, and the capacitor C1 are grounded.

[0004] Furthermore, it further includes several operational amplifiers and diodes. The non-inverting input terminal of the operational amplifier U2 among the several operational amplifiers is connected to the fifth pin of the flip-flop U1, the inverting input terminal is connected to one end of the resistors R1 and R2, and the output terminal is connected to the gates of the MOS transistors Q1 and Q4; the non-inverting input terminal of the operational amplifier U3 is connected to the cathode of the diode D1 and one end of the capacitor C2, the inverting input terminal is connected to one end of the resistors R11 and R12, and the output terminal is connected to the gate of the MOS transistor Q7; the drain of the MOS transistor Q4 is connected to the gate of the MOS transistor Q2, and the source is connected to one end of the resistor R9; the anode of the diode D1 is connected to the other end of the resistor R9; the other ends of the resistors R2 and R11 are connected to the power supply; the other ends of the resistors R1, R12, and the capacitor C2 are grounded.

[0005] Further, the gate of MOS transistor Q5 among the several MOS transistors is connected to the cathode of diode D3, the source is connected to one ends of resistor R16 and resistor R17, and the drain is connected to the anode of diode D2; the cathode of diode D2 is connected to the non-inverting input terminal of operational amplifier U3 and terminal P4 of the connector; the anode of diode D3 is connected to the output terminal of operational amplifier U2; the other end of resistor R16 is connected to the power supply; the other end of resistor R17 is grounded.

[0006] Further, the source of MOS transistor Q9 among the several MOS transistors is connected to terminal P2 of the connector, the gate is connected to the output terminal of operational amplifier U3, and the drain is connected to the anode of diode D4; the cathode of diode D4 is connected to one end of resistor R15; the other end of resistor R15 is connected to terminal P4 of the connector.

[0007] Further, the drain of MOS transistor Q6 among the several MOS transistors is connected to terminal P4 of the connector, the gate is connected to the gate of MOS transistor Q8, one end of resistor R5, and terminal P3 of the connector; the drain of MOS transistor Q8 is connected to the first pin of trigger U1; the sources of MOS transistors Q6 and Q8 and the other end of resistor R5 are grounded.

[0008] Further, one end of resistor R10 among the several resistors is connected to the gate of MOS transistor Q7, and the other end is grounded.

[0009] Further, one end of resistor R7 among the several resistors is connected to the gate of MOS transistor Q2, and the other end is grounded.

[0010] Further, one end of resistor R8 among the several resistors is connected to the gate of MOS transistor Q4, and the other end is grounded.

[0011] Further, one end of resistor R18 among the several resistors is connected to the gate of MOS transistor Q5, and the other end is grounded.

[0012] The beneficial effects of the present invention compared with the prior art are as follows:

[0013] The present invention can make the charging current of the battery smoothly increase based on the current amplitude allowed for charging in the low-temperature range after the battery temperature changes from the low-temperature range to the appropriate temperature range, and can limit the charging current of the battery when the battery temperature jumps reversely between the two temperature ranges due to environmental factors, and wait until the battery temperature stabilizes in the appropriate temperature range and then increase smoothly again. Description of the Drawings

[0014] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for use in the prior art and the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained according to these drawings without creative efforts.

[0015] Figure 1The circuit structure diagram provided by the present invention. Detailed implementation manners

[0016] In order to make the objectives and advantages of the present invention more clear and understandable, the present invention will be specifically described below in conjunction with embodiments. It should be understood that the following text is only used to describe one or several specific implementation manners of the present invention, and does not strictly limit the scope of protection of the specific claims of the present invention.

[0017] The present invention discloses a control circuit for a battery charging temperature protection chip, which includes a plurality of MOS transistors, a plurality of resistors, a flip-flop, a capacitor, and a connector. The source of the MOS transistor Q1 among the plurality of MOS transistors is connected to the drain of the MOS transistor Q3 and one end of the resistor R4, and the drain is connected to the third pin of the flip-flop U1 and one end of the resistor R14; the gate of the MOS transistor Q2 is connected to the gate of the MOS transistor Q3 and the drain of the MOS transistor Q7, the source is connected to the source of the MOS transistor Q3, one end of the capacitor C1, and one end of the resistor R13, and the drain is connected to one end of the resistor R3; the first pin of the flip-flop U1 is connected to one end of the resistor R6, the second pin is connected to the sixth pin, and the fourth pin, the resistor R3, and the other end of the resistor R6 are connected to the power supply; the source of the MOS transistor Q7 is connected to the terminal P1 of the connector; the other ends of the resistor R4, the resistor R13, the resistor R14, and the capacitor C1 are grounded.

[0018] Specifically, it further includes a plurality of operational amplifiers and diodes. The non-inverting input terminal of the operational amplifier U2 among the plurality of operational amplifiers is connected to the fifth pin of the flip-flop U1, the inverting input terminal is connected to one end of the resistors R1 and R2, and the output terminal is connected to the gates of the MOS transistors Q1 and Q4; the non-inverting input terminal of the operational amplifier U3 is connected to the cathode of the diode D1 and one end of the capacitor C2, the inverting input terminal is connected to one ends of the resistors R11 and R12, and the output terminal is connected to the gate of the MOS transistor Q7; the drain of the MOS transistor Q4 is connected to the gate of the MOS transistor Q2, and the source is connected to one end of the resistor R9; the anode of the diode D1 is connected to the other end of the resistor R9; the other ends of the resistors R2 and R11 are connected to the power supply; the other ends of the resistors R1, R12, and the capacitor C2 are grounded.

[0019] Specifically, the gate of the MOS transistor Q5 among the plurality of MOS transistors is connected to the cathode of the diode D3, the source is connected to one ends of the resistors R16 and R17, and the drain is connected to the anode of the diode D2; the cathode of the diode D2 is connected to the non-inverting input terminal of the operational amplifier U3 and the terminal P4 of the connector; the anode of the diode D3 is connected to the output terminal of the operational amplifier U2; the other end of the resistor R16 is connected to the power supply; the other end of the resistor R17 is grounded.

[0020] Specifically, the source of the MOS transistor Q9 among the plurality of MOS transistors is connected to the terminal P2 of the connector, the gate is connected to the output terminal of the operational amplifier U3, and the drain is connected to the anode of the diode D4; the cathode of the diode D4 is connected to one end of the resistor R15; the other end of the resistor R15 is connected to the terminal P4 of the connector.

[0021] Specifically, the drain of MOS transistor Q6 among the several MOS transistors is connected to the terminal of connector P4, the gate is connected to the gate of MOS transistor Q8, one end of resistor R5, and the terminal of connector P3; the drain of MOS transistor Q8 is connected to the first pin of trigger U1; the sources of MOS transistors Q6 and Q8 and the other end of resistor R5 are grounded.

[0022] Specifically, one end of resistor R10 among the several resistors is connected to the gate of MOS transistor Q7, and the other end is grounded.

[0023] Specifically, one end of resistor R7 among the several resistors is connected to the gate of MOS transistor Q2, and the other end is grounded.

[0024] Specifically, one end of resistor R8 among the several resistors is connected to the gate of MOS transistor Q4, and the other end is grounded.

[0025] Specifically, one end of resistor R18 among the several resistors is connected to the gate of MOS transistor Q5, and the other end is grounded.

[0026] The first pin of the flip-flop U1 is ~1CLR, the second pin is 1D, the third pin is 1CLK, the fourth pin is ~1PR, the fifth pin is 1Q, and the sixth pin is ~1Q. MOS transistors Q1, Q3, Q5, Q7, and Q9 are PMOS transistors, and MOS transistors Q2, Q4, Q6, and Q8 are NMOS transistors. A detection unit is provided in the control circuit, and a temperature range is set on the detection unit. The detection unit feeds back a corresponding signal to the control circuit based on the battery temperature and the set temperature range. When the battery starts charging and its temperature is within the low-temperature range, the detection unit feeds back a preheating start signal for low-temperature charging start to the control circuit. After the battery temperature rises from the low-temperature range to the appropriate temperature range, the inspection unit continuously feeds back a preheating end signal for low-temperature charging start to the control circuit. The connector P1 on the control circuit is used to receive the preheating start / preheating end signal for low-temperature charging start. When the control circuit receives the feedback of the preheating signal (preheating start signal) for the first time, the signal is fed back to the gates of MOS transistor Q2 and MOS transistor Q3 through the source and drain of MOS transistor Q7. The resistor R7 is used to discharge the parasitic capacitance of the gates of MOS transistor Q2 and MOS transistor Q3. The voltage difference between the gate and source of MOS transistor Q2 is higher than the conduction threshold, and MOS transistor Q2 conducts. The power supply signal passes through resistor R3, the drain and source of MOS transistor Q2, and resistor R13 to the ground terminal, and the potential of capacitor C1 rises. At the same time, the voltage difference between the gate and source of MOS transistor Q3 is higher than the conduction threshold, and MOS transistor Q3 cuts off. When the control circuit loses the feedback of the preheating signal, MOS transistor Q2 cuts off and MOS transistor Q3 conducts. The signal at the capacitor C1 terminal passes through resistor R4 to the ground terminal, and the potential of the capacitor C1 terminal drops. The signal at the resistor R4 terminal passes through the source and drain of MOS transistor Q1 and resistor R14 to the ground terminal, and the signal at the resistor R14 terminal is fed back to the third pin of the flip-flop U1 so that the third pin of the flip-flop U1 can obtain a high-level signal once. The fifth pin of the flip-flop U1 outputs a high level. The power supply signal is fed back to the first pin of the flip-flop U1 through resistor R6, and the power supply signal passes through resistor R2 and resistor R1 to the ground terminal. When the fifth pin of the flip-flop U1 is at a high level, the operational amplifier U2 outputs. The signal at the output terminal of the operational amplifier U2 is fed back to the gates of MOS transistor Q1 and MOS transistor Q4. The resistor R8 is used to discharge the parasitic capacitance of the gates of MOS transistor Q1 and MOS transistor Q4. The voltage difference between the gate and source of MOS transistor Q1 is higher than the conduction threshold, and MOS transistor Q1 cuts off. The cutoff of MOS transistor Q1 limits the flip-flop U1 from obtaining a high-level signal feedback at its third pin again when the control circuit receives the feedback of the second preheating signal (preheating end signal). The voltage difference between the gate and source of MOS transistor Q4 is higher than the conduction threshold, and MOS transistor Q4 conducts. When the control circuit receives the feedback of the second preheating signal (preheating end signal),The signal passes through the source of MOS transistor Q7, the drain of MOS transistor Q7, the drain of MOS transistor Q4, the source of MOS transistor Q4, resistor R9, and diode D1, causing the potential at the end of capacitor C2 to rise. At the same time, the signal at the end of capacitor C2 is fed back to the adjustment unit through connector P4. The adjustment unit adjusts the charging current of the battery accordingly based on the amplitude of this signal. The higher the amplitude of the signal at the end of capacitor C2, the greater the charging current of the battery. By adjusting the resistance value of resistor R9 or the capacitance value of capacitor C2, the rising rate and smoothness of the charging current are changed. When the battery temperature rises from the low-temperature range to the appropriate temperature range due to environmental factors and then jumps back to the low-temperature range again, the anti-reverse function of diode D1 keeps the potential at the end of capacitor C2 at the current amplitude, so that the charging current of the battery can stop rising after the battery temperature jumps back and forth between the two temperature ranges. When the battery temperature is re-stabilized in the appropriate temperature range, the charging current of the battery can rise smoothly again. The power supply signal passes through resistor R11 and resistor R12 to the ground terminal. The signal at the end of resistor R12 is the reference signal for the allowable charging current when the battery is in the appropriate temperature range, which is set by adjusting the resistance value of resistor R12. The signal at the end of resistor R12 is fed back to the inverting terminal of operational amplifier U3. When the charging current reaches the reference signal for the allowable charging current at the appropriate temperature, operational amplifier U3 outputs. The signal at the output terminal of operational amplifier U3 is fed back to the gate of MOS transistor Q7. The voltage difference between the gate and the source of MOS transistor Q7 is higher than the conduction threshold, and MOS transistor Q7 is turned off, and the control circuit closes the feedback channel of the preheating signal.

[0027] The power supply signal passes through resistor R16 and resistor R17 to the ground terminal. The signal at the resistor R17 terminal is a reference signal for the charging current allowed when the battery is in the low-temperature range. The signal at the resistor R17 terminal passes through the source of MOS transistor Q5, the drain of MOS transistor Q5, and diode D2 to raise the potential of capacitor C2 and make it consistent with the amplitude of the reference signal for the charging current allowed in the low-temperature range. When the operational amplifier U2 outputs, the signal at the output terminal of operational amplifier U2 is fed back to the gate of MOS transistor Q5 through diode D3. Resistor R18 is used to discharge the parasitic capacitance of the gate of MOS transistor Q5. When the voltage difference between the gate and the source of MOS transistor Q5 is higher than the conduction threshold, MOS transistor Q5 is cut off. In this way, after the battery temperature rises from the low-temperature range to the appropriate temperature range, the signal at the capacitor C2 terminal can continue to rise based on the amplitude of the reference signal for the charging current allowed in the low-temperature range. The signal at the output terminal of operational amplifier U3 is synchronously fed back to the gate of MOS transistor Q9. Resistor R10 is used to discharge the parasitic capacitance of the gates of MOS transistors Q7 and Q9. When the operational amplifier U3 outputs, the voltage difference between the gate and the source of MOS transistor Q9 is higher than the conduction threshold, and MOS transistor Q9 is cut off. If the battery starts charging and is within the appropriate temperature range, the detection unit feeds back an appropriate-temperature start-charging signal to the control circuit. The connector P2 on the control circuit is used to receive the appropriate-temperature start-charging signal. This signal passes through the source of MOS transistor Q9, the drain of MOS transistor Q9, diode D4, and resistor R15 to raise the potential of capacitor C2. Adjust the resistance values of resistor R15 and resistor R9 to be the same so that the rising rates and smoothness of the battery charging current in the two start-charging states are the same. The connector P3 on the control circuit is used to receive the reset signal. The signal at the connector P3 terminal is fed back to the gates of MOS transistors Q6 and Q8. Resistor R5 is used to discharge the parasitic capacitance of the gates of MOS transistors Q6 and Q8. When the connector P3 on the control circuit obtains the signal feedback, the voltage difference between the gate and the source of MOS transistor Q8 is higher than the conduction threshold, and MOS transistor Q8 conducts. The signal at the drain terminal of MOS transistor Q8 is pulled to the ground potential, and the flip-flop U1 is reset. The fifth pin of the flip-flop U1 is at a low level, and the operational amplifier U2 is cut off. At the same time, the voltage difference between the gate and the source of MOS transistor Q6 is higher than the conduction threshold, and MOS transistor Q6 conducts. The signal at the capacitor C1 terminal is pulled to the ground potential, and the control circuit is reset.

[0028] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and without departing from the spirit or basic characteristics of the present invention, the present invention can be implemented in other specific forms.

Claims

1. A control circuit for a battery charging temperature protection chip, characterized in that, It includes several MOS transistors, several resistors, several operational amplifiers, flip-flops, capacitors, connectors, and diodes. The source of MOS transistor Q1 among the several MOS transistors is connected to the drain of MOS transistor Q3 and one end of resistor R4, and the drain is connected to the third pin of flip-flop U1 and one end of resistor R14. The gate of MOS transistor Q2 is connected to the gate of MOS transistor Q3 and the drain of MOS transistor Q7, the source is connected to the source of MOS transistor Q3, one end of capacitor C1, and one end of resistor R13, and the drain is connected to one end of resistor R3. The first pin of flip-flop U1 is connected to one end of resistor R6, the second pin is connected to the sixth pin, and the fourth pin, resistor R3, and the other end of resistor R6 are connected to the power supply. The source of MOS transistor Q7 is connected to terminal P1 of the connector. The other ends of resistor R4, resistor R13, resistor R14, and capacitor C1 are grounded. The non-inverting input terminal of operational amplifier U2 is connected to the fifth pin of flip-flop U1, the inverting input terminal is connected to one end of resistor R1 and resistor R2, and the output terminal is connected to the gates of MOS transistor Q1 and MOS transistor Q4. The non-inverting input terminal of operational amplifier U3 is connected to the cathode of diode D1 and one end of capacitor C2, the inverting input terminal is connected to one end of resistor R11 and resistor R12, and the output terminal is connected to the gate of MOS transistor Q7. The drain of MOS transistor Q4 is connected to the gate of MOS transistor Q2, and the source is connected to one end of resistor R9. The anode of diode D1 is connected to the other end of resistor R9. The other ends of resistor R2 and resistor R11 are connected to the power supply. The other ends of resistor R1, resistor R12, and capacitor C2 are grounded. The gate of MOS transistor Q5 among the MOS transistors is connected to the cathode of diode D3, the source is connected to one end of resistor R16 and resistor R17, and the drain is connected to the anode of diode D2. The cathode of diode D2 is connected to the non-inverting input terminal of operational amplifier U3 and terminal P4 of the connector. The anode of diode D3 is connected to the output terminal of operational amplifier U2. The other end of resistor R16 is connected to the power supply. The other end of resistor R17 is grounded. Connector P1 is used to receive the preheating start / preheating end signal for low-temperature start-up charging. When the control circuit first obtains the preheating signal feedback, MOS transistor Q2 conducts and MOS transistor Q3 cuts off. When the control circuit loses the preheating signal feedback, MOS transistor Q2 cuts off and MOS transistor Q3 conducts, and the third pin of flip-flop U1 can obtain a high-level signal once. The fifth pin of flip-flop U1 outputs a high level, operational amplifier U2 outputs, MOS transistor Q1 cuts off, and the cut-off of MOS transistor Q1 enables the control circuit to limit the third pin of flip-flop U1 from obtaining a high-level signal feedback again when obtaining the second preheating signal feedback, and MOS transistor Q4 conducts. When the control circuit obtains the second preheating signal feedback, the potential at the C2 terminal of the capacitor rises, and at the same time, the signal at the C2 terminal of the capacitor is fed back to the adjustment unit through connector P4.

2. The control circuit of the battery charging temperature protection chip according to claim 1, wherein The source of MOS transistor Q9 among the several MOS transistors is connected to terminal P2 of the connector, the gate is connected to the output terminal of operational amplifier U3, and the drain is connected to the anode of diode D4. The cathode of diode D4 is connected to one end of resistor R15. The other end of resistor R15 is connected to terminal P4 of the connector. Connector P2 is used to receive the start-up charging signal at an appropriate temperature.

3. The control circuit of the battery charging temperature protection chip according to claim 1, characterized in that, The drain of MOS transistor Q6 among the several MOS transistors is connected to the terminal of connector P4, the gate is connected to the gate of MOS transistor Q8, one end of resistor R5, and the terminal of connector P3; the drain of MOS transistor Q8 is connected to the first pin of trigger U1; the sources of MOS transistor Q6 and MOS transistor Q8 and the other end of resistor R5 are grounded; connector P3 is used to receive a reset signal.

4. The control circuit of the battery charging temperature protection chip according to claim 1, characterized in that, One end of resistor R10 among the several resistors is connected to the gate of MOS transistor Q7, and the other end is grounded.

5. The control circuit of the battery charging temperature protection chip according to claim 1, characterized in that, One end of resistor R7 among the several resistors is connected to the gate of MOS transistor Q2, and the other end is grounded.

6. The control circuit of the battery charging temperature protection chip according to claim 1, characterized in that One end of resistor R8 among the several resistors is connected to the gate of MOS transistor Q4, and the other end is grounded.

7. The control circuit of the battery charging temperature protection chip according to claim 1, characterized in that One end of resistor R18 among the several resistors is connected to the gate of MOS transistor Q5, and the other end is grounded.

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