Control circuit of battery charging temperature protection chip

Abstract

The invention relates to the technical field of electronic circuits, and discloses a control circuit of a battery charging temperature protection chip, the control circuit comprises a plurality of MOS tubes, a plurality of resistors, a trigger, a capacitor and a connector, the source electrode of the MOS tube Q1 in the plurality of MOS tubes is connected with the drain electrode of the MOS tube Q3 and one end of the resistor R4, and the drain electrode is connected with the third pin of the trigger U1 and one end of the resistor R14; the grid electrode of the MOS tube Q2 is connected with the grid electrode of the MOS tube Q3 and the drain electrode of the MOS tube Q7, the source electrode is connected with the source electrode of the MOS tube Q3, one end of the capacitor C1 and one end of the resistor R13, and the drain electrode is connected with one end of the resistor R3; a first pin of the trigger U1 is connected with one end of a resistor R6, a second pin is connected with a sixth pin, a fourth pin and a resistor R3, and the other end of the resistor R6 is connected with a power supply; the source electrode of the MOS tube Q7 is connected with the P1 end of the connector; and 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 in particular to a control circuit of a battery charging temperature protection chip. Background Art

[0002] In order to shorten the charging time and protect the battery life, the battery is often required to be preheated when it is in a low temperature state and charging begins. During the preheating period, the charging current is maintained at a low amplitude. During the preheating period, the battery temperature will gradually rise. When the battery temperature is in a suitable temperature range, the battery charging current will be adjusted in steps based on the real-time temperature of the battery. However, the instantaneous fluctuation of the step-by-step change of the charging current will make the internal reaction of the battery unbalanced and cause the battery temperature to rise suddenly. Therefore, a control circuit of a battery charging temperature protection chip is proposed, which can make the battery charging current smoothly rise 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 suitable temperature range, and when the battery temperature jumps in the opposite direction between the two temperature ranges due to environmental factors, the battery charging current is limited so that the battery temperature can be smoothly increased again after stabilizing in the suitable temperature range. Summary of the invention

[0003] In view of the above technical problems, the object of the present invention is to provide a control circuit of a battery charging temperature protection chip, comprising a plurality of MOS tubes, a plurality of resistors, a trigger, a capacitor, and a connector, wherein the source of the MOS tube Q1 in the plurality of MOS tubes is connected to the drain of the MOS tube Q3 and one end of the resistor R4, and the drain is connected to the third pin of the trigger U1 and one end of the resistor R14; the gate of the MOS tube Q2 is connected to the gate of the MOS tube Q3 and the drain of the MOS tube Q7, the source is connected to the source of the MOS tube Q3, one end of the capacitor C1, one end of the resistor R13, and the drain is connected to one end of the resistor R3; the first pin of the trigger 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 a power supply; the source of the MOS tube Q7 is connected to the end of the connector P1; the other ends of the resistors R4, R13, R14, and the capacitor C1 are grounded.

[0004] Furthermore, it also includes several operational amplifiers and diodes. Among the several operational amplifiers, the operational amplifier U2 is connected to the fifth pin of the trigger U1 in the same phase, connected to one end of the resistor R1 and the resistor R2 in the opposite phase, and connected to the gate of the MOS tube Q1 and the MOS tube Q4 at the output end; the operational amplifier U3 is connected to the cathode of the diode D1 and one end of the capacitor C2 in the same phase, connected to one end of the resistor R11 and the resistor R12 in the opposite phase, and connected to the gate of the MOS tube Q7 at the output end; the drain of the MOS tube Q4 is connected to the gate of the MOS tube 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] Furthermore, the gate of the MOS tube Q5 among the plurality of MOS tubes is connected to the cathode of the diode D3, the source is connected to the resistor R16 and one end of the resistor R17, and the drain is connected to the anode of the diode D2; the cathode of the diode D2 is connected to the in-phase end of the operational amplifier U3 and the end of the connector P4; the anode of the diode D3 is connected to the output end of the operational amplifier U2; the other end of the resistor R16 is connected to the power supply; and the other end of the resistor R17 is grounded.

[0006] Furthermore, the source of the MOS tube Q9 among the plurality of MOS tubes is connected to the connector P2 end, the gate is connected to the output end of the operational amplifier U3, 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 connector P4 end.

[0007] Furthermore, the drain of the MOS tube Q6 among the plurality of MOS tubes is connected to the connector P4 end, and the gate is connected to the gate of the MOS tube Q8, one end of the resistor R5, and the connector P3 end; the drain of the MOS tube Q8 is connected to the first pin of the trigger U1; the sources of the MOS tube Q6, the MOS tube Q8, and the other end of the resistor R5 are grounded.

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

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

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

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

[0012] The beneficial effects of the present invention compared with the prior art are: The present invention can enable the charging current of the battery to increase 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 suitable temperature range. When the battery temperature jumps in the opposite direction between two temperature ranges due to environmental factors, the charging current of the battery can be limited so as to increase smoothly again after the battery temperature stabilizes in the suitable temperature range. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the prior art and the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0014] Figure 1 This is a circuit structure diagram provided by the present invention. DETAILED DESCRIPTION

[0015] In order to make the objects and advantages of the present invention more clearly understood, the present invention is specifically described below in conjunction with embodiments. It should be understood that the following text is only used to describe one or several specific implementations of the present invention, and does not strictly limit the scope of protection specifically requested by the present invention.

[0016] The invention discloses a control circuit of a battery charging temperature protection chip, comprising a plurality of MOS tubes, a plurality of resistors, a trigger, a capacitor and a connector. The source of a MOS tube Q1 among the plurality of MOS tubes is connected to the drain of a MOS tube Q3 and one end of a resistor R4, and the drain is connected to the third pin of a trigger U1 and one end of a resistor R14; the gate of a MOS tube Q2 is connected to the gate of a MOS tube Q3 and the drain of a MOS tube Q7, the source is connected to the source of a MOS tube Q3, one end of a capacitor C1 and one end of a resistor R13, and the drain is connected to one end of the resistor R3; the first pin of the trigger U1 is connected to one end of a 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 a power supply; the source of the MOS tube Q7 is connected to the end of a connector P1; the other ends of the resistors R4, R13, R14 and the capacitor C1 are grounded.

[0017] Specifically, it also includes several operational amplifiers and diodes. Among the several operational amplifiers, the operational amplifier U2 is connected to the fifth pin of the trigger U1 in the same phase, connected to the resistor R1 and one end of the resistor R2 in the opposite phase, and connected to the gate of the MOS tube Q1 and the MOS tube Q4 in the output end; the operational amplifier U3 is connected to the cathode of the diode D1 and one end of the capacitor C2 in the same phase, connected to the resistor R11 and one end of the resistor R12 in the opposite phase, and connected to the gate of the MOS tube Q7 in the output end; the drain of the MOS tube Q4 is connected to the gate of the MOS tube 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.

[0018] Specifically, the gate of the MOS tube Q5 among the plurality of MOS tubes is connected to the cathode of the diode D3, the source is connected to the resistor R16 and one end of the resistor R17, and the drain is connected to the anode of the diode D2; the cathode of the diode D2 is connected to the in-phase end of the operational amplifier U3 and the end of the connector P4; the anode of the diode D3 is connected to the output end of the operational amplifier U2; the other end of the resistor R16 is connected to the power supply; and the other end of the resistor R17 is grounded.

[0019] Specifically, the source of the MOS tube Q9 among the plurality of MOS tubes is connected to the connector P2 end, the gate is connected to the output end of the operational amplifier U3, 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 connector P4 end.

[0020] Specifically, the drain of the MOS tube Q6 among the several MOS tubes is connected to the connector P4 end, and the gate is connected to the gate of the MOS tube Q8, one end of the resistor R5, and the connector P3 end; the drain of the MOS tube Q8 is connected to the first pin of the trigger U1; the sources of the MOS tube Q6, the MOS tube Q8, and the other end of the resistor R5 are grounded.

[0021] Specifically, one end of the resistor R10 among the plurality of resistors is connected to the gate of the MOS transistor Q7 , and the other end is grounded.

[0022] Specifically, one end of the resistor R7 among the plurality of resistors is connected to the gate of the MOS transistor Q2 , and the other end is grounded.

[0023] Specifically, one end of the resistor R8 among the plurality of resistors is connected to the gate of the MOS transistor Q4 , and the other end is grounded.

[0024] Specifically, one end of the resistor R18 among the plurality of resistors is connected to the gate of the MOS transistor Q5 , and the other end is grounded.

[0025] A detection unit is set in the control circuit, and the 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. If the battery starts to charge and its temperature is in the low temperature range, the detection unit feeds back a preheating start signal for low temperature charging to the control circuit. After the battery temperature rises from the low temperature range to the appropriate temperature range, the detection unit continuously feeds back a preheating end signal for low temperature charging 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. When the control circuit obtains the preheating signal (preheating start signal) feedback for the first time, the signal is fed back to the gate of MOS tube Q2 and MOS tube Q3 via the source and drain of MOS tube Q7. The gate, resistor R7 is used to discharge the parasitic capacitance of the gate of MOS tube Q2 and the gate of MOS tube Q3. The voltage difference between the gate of MOS tube Q2 and the source of MOS tube Q2 is higher than the conduction threshold, MOS tube Q2 is turned on, and the power signal is connected to the ground terminal through resistor R3, MOS tube Q2 drain, MOS tube Q2 source, and resistor R13. The potential of capacitor C1 rises. At the same time, the voltage difference between the gate of MOS tube Q3 and the source of MOS tube Q3 is higher than the conduction threshold, and MOS tube Q3 is turned off. When the control circuit loses the preheating signal feedback, MOS tube Q2 is turned off, MOS tube Q3 is turned on, and the signal at the capacitor C1 end is connected to the ground terminal through resistor R4. The potential of capacitor C1 decreases, and the signal at the resistor R4 end is connected to the ground terminal through the source of MOS tube Q1, the drain of MOS tube Q1, and the resistor R13. The resistor R14 is connected to the ground terminal, and the signal at the resistor R14 end is fed back to the third pin of the trigger U1 so that the third pin of the trigger U1 can obtain a high-level signal. The fifth pin of the trigger U1 outputs a high level. The power signal is fed back to the first pin of the trigger U1 through the resistor R6. The power signal is connected to the ground terminal through the resistor R2 and the resistor R1. When the fifth pin of the trigger U1 is at a high level, the operational amplifier U2 outputs, and the output signal of the operational amplifier U2 is fed back to the gate of the MOS tube Q1 and the gate of the MOS tube Q4. The resistor R8 is used to discharge the parasitic capacitance of the gate of the MOS tube Q1 and the gate of the MOS tube Q4. The voltage difference between the gate of the MOS tube Q1 and the source of the MOS tube Q1 is higher than the conduction threshold, and the MOS tube Q1 is turned off. The MOS tube Q1 is turned off to make the control When the control circuit obtains the second preheating signal (preheating end signal) feedback, the third pin of the limiting trigger U1 obtains the high-level signal feedback again, and the voltage difference between the gate of the MOS tube Q4 and the source of the MOS tube Q4 is higher than the conduction threshold, and the MOS tube Q4 is turned on. When the control circuit obtains the second preheating signal (preheating end signal) feedback, the signal passes through the source of the MOS tube Q7, the drain of the MOS tube Q7, the drain of the MOS tube Q4, the source of the MOS tube Q4, the resistor R9, and the diode D1 to increase the potential of the capacitor C2 end. At the same time, the signal at the capacitor C2 end is fed back to the regulating unit through the connector P4. The regulating unit adjusts the charging current of the battery accordingly based on the amplitude of the signal. The higher the amplitude of the signal at the capacitor C2 end, 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 suitable temperature range due to environmental factors and then jumps to the low temperature range again, the diode D1 prevents reverse flow and maintains the capacitor C2 end at the current amplitude, so that the battery charging current can stop rising after the battery temperature reversely jumps between the two temperature ranges, and when the battery temperature stabilizes in the suitable temperature range again, the battery charging current can rise smoothly again. The power signal passes through resistors R11 and R12 to the ground end. The signal at the resistor R12 end is the reference signal for the charging current allowed when the battery is in the suitable temperature range. It is set by adjusting the resistance value of resistor R12. The signal at the resistor R12 end is fed back to the inverting end of the op amp U3. When the charging current reaches the reference signal for the charging current allowed at the suitable temperature, the op amp U3 outputs, and the signal at the output end of the op amp U3 is fed back to the gate of the MOS tube Q7. The voltage difference between the gate of the MOS tube Q7 and the source of the MOS tube Q7 is higher than the conduction threshold, the MOS tube Q7 is cut off, and the control circuit closes the feedback channel of the preheating signal.

[0026] The power supply signal passes through resistors R16 and R17 to the ground terminal. The signal at the resistor R17 terminal is a reference signal for the allowable charging current when the battery is in a low temperature range. The signal at the resistor R17 terminal passes through the source of the MOS tube Q5, the drain of the MOS tube Q5, and the diode D2 to increase the potential of the capacitor C2 and make it consistent with the amplitude of the reference signal for the allowable charging current in the low temperature range. When the operational amplifier U2 outputs, the output signal of the operational amplifier U2 is fed back to the gate of the MOS tube Q5 through the diode D3. The resistor R18 is used to discharge the parasitic capacitance of the gate of the MOS tube Q5. The gate of the MOS tube Q5 and the MOS tube Q 5 source voltage difference is higher than the conduction threshold, MOS tube Q5 is cut off, so that after the battery temperature rises from the low temperature range to the appropriate temperature range, the capacitor C2 end signal can continue to rise based on the reference signal amplitude of the charging current allowed in the low temperature range, and the operational amplifier U3 output end signal is synchronously fed back to the MOS tube Q9 gate, and the resistor R10 is used to discharge the parasitic capacitance of the MOS tube Q7 gate and the MOS tube Q9 gate. When the operational amplifier U3 outputs, the voltage difference between the MOS tube Q9 gate and the MOS tube Q9 source is higher than the conduction threshold, and the MOS tube Q9 is cut off. If the battery starts to charge and it is in an appropriate temperature range, When the temperature is within the appropriate range, the detection unit feeds back the appropriate temperature start-up signal to the control circuit. The connector P2 on the control circuit is used to receive the appropriate temperature start-up signal. The signal passes through the source of the MOS tube Q9, the drain of the MOS tube Q9, the diode D4, and the resistor R15 to increase the potential of the capacitor C2. The resistance values ​​of the resistor R15 and the resistor R9 are adjusted to be consistent so that the rising rate and smoothness of the battery charging current in the two start-up states are consistent. The connector P3 on the control circuit is used to receive the reset signal. The signal at the connector P3 end is fed back to the gate of the MOS tube Q6 and the gate of the MOS tube Q8. The resistor R5 is used to discharge the parasitic capacitance of the gate of MOS tube Q6 and the gate of MOS tube Q8. When the connector P3 on the control circuit obtains signal feedback, the voltage difference between the gate of MOS tube Q8 and the source of MOS tube Q8 is higher than the conduction threshold, MOS tube Q8 is turned on, the signal at the drain end of MOS tube Q8 is pulled to the ground potential, the trigger U1 is reset, the fifth pin of the trigger U1 is at a low level, the operational amplifier U2 is cut off, and at the same time, the voltage difference between the gate of MOS tube Q6 and the source of MOS tube Q6 is higher than the conduction threshold, MOS tube Q6 is turned on, the signal at the capacitor C1 end is pulled to the ground potential, and the control circuit is reset.

[0027] It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention.

Claims

1. A control circuit of a battery charging temperature protection chip, characterized in that: The invention comprises a plurality of MOS tubes, a plurality of resistors, a trigger, a capacitor and a connector. The source of the MOS tube Q1 in the plurality of MOS tubes is connected to the drain of the MOS tube Q3 and one end of the resistor R4, and the drain is connected to the third pin of the trigger U1 and one end of the resistor R14; the gate of the MOS tube Q2 is connected to the gate of the MOS tube Q3 and the drain of the MOS tube Q7, the source is connected to the source of the MOS tube 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 trigger 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 tube Q7 is connected to the end of the connector P1; the other ends of the resistors R4, R13, R14 and the capacitor C1 are grounded.

2. The control circuit of the battery charging temperature protection chip according to claim 1, characterized in that: It also includes several operational amplifiers and diodes. Among the operational amplifiers, the operational amplifier U2 is connected to the fifth pin of the trigger U1 in the same phase, connected to the resistor R1 and one end of the resistor R2 in the opposite phase, and connected to the gate of the MOS tube Q1 and the MOS tube Q4 at the output end; the operational amplifier U3 is connected to the cathode of the diode D1 and one end of the capacitor C2 in the same phase, connected to the resistor R11 and one end of the resistor R12 in the opposite phase, and connected to the gate of the MOS tube Q7 at the output end; the drain of the MOS tube Q4 is connected to the gate of the MOS tube 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.

3. The control circuit of the battery charging temperature protection chip according to claim 2, characterized in that: The gate of the MOS tube Q5 among the several MOS tubes is connected to the cathode of the diode D3, the source is connected to the resistor R16 and one end of the resistor R17, and the drain is connected to the anode of the diode D2; the cathode of the diode D2 is connected to the in-phase end of the operational amplifier U3 and the end of the connector P4; the anode of the diode D3 is connected to the output end of the operational amplifier U2; the other end of the resistor R16 is connected to the power supply; and the other end of the resistor R17 is grounded.

4. The control circuit of the battery charging temperature protection chip according to claim 3, characterized in that: The source of the MOS tube Q9 among the plurality of MOS tubes is connected to the connector P2 end, the gate is connected to the output end of the operational amplifier U3, 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 connector P4 end.

5. The control circuit of the battery charging temperature protection chip according to claim 3, characterized in that: The drain of the MOS tube Q6 among the plurality of MOS tubes is connected to the connector P4 end, and the gate is connected to the gate of the MOS tube Q8, one end of the resistor R5, and the connector P3 end; the drain of the MOS tube Q8 is connected to the first pin of the trigger U1; the sources of the MOS tube Q6, the MOS tube Q8, and the other end of the resistor R5 are grounded.

6. The control circuit of the battery charging temperature protection chip according to claim 1, characterized in that: One end of the resistor R10 among the plurality of resistors is connected to the gate of the MOS transistor Q7 , 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 the resistor R7 among the plurality of resistors is connected to the gate of the MOS transistor Q2 , and the other end is grounded.

8. The control circuit of the battery charging temperature protection chip according to claim 2, characterized in that: One end of the resistor R8 among the plurality of resistors is connected to the gate of the MOS transistor Q4 , and the other end is grounded.

9. The control circuit of the battery charging temperature protection chip according to claim 3, characterized in that: One end of the resistor R18 among the plurality of resistors is connected to the gate of the MOS transistor Q5 , and the other end is grounded.

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