Lithium battery delay protection circuit, battery and electronic product

Abstract

The utility model relates to the technical field of power supplies, in particular to a lithium battery delay protection circuit, a battery and an electronic product. The lithium battery delay protection circuit comprises a power supply, a resistor R1, a capacitor C1, a chip U1, an MOS tube Q1 and a capacitor C2, one end of the resistor R1 is connected with the positive electrode of the power supply, the other end of the resistor R1 is connected with a VDD pin of the chip U1 and one end of the capacitor C1, the other end of the capacitor C1 is connected with a VSS pin of the chip U1, an S1 pin of the MOS tube Q1 and the negative electrode of the power supply, and the capacitor C2 is connected with the chip U1. A pin G1 of the MOS tube Q1 is connected with a pin DOUT of the chip U1, and a pin G2 of the MOS tube Q1 is connected with a pin COUT of the chip U1; and the capacitor C2 is connected between the positive electrode and the negative electrode of the power supply and is connected in parallel with the capacitor C1. According to the circuit structure, the over-discharge voltage protection delay time is increased, the conditions that over-discharge voltage protection is triggered in advance by large voltage drop of a power supply, a product is shut down abnormally and cannot be used can be prevented, and the use experience of a user is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of power supplies, in particular to a lithium battery delay protection circuit, a battery and an electronic product. Background Art

[0002] With the increasing use power of electronic products, the discharge current / discharge power of the power supply is getting higher and higher; limited by the lithium power supply technology, when corresponding electronic products perform high-rate discharge at large currents, for example, for an electronic cigarette product, the smoking time is 2 s, while the over-discharge protection delay time of a general lithium battery delay protection circuit is usually 30 ms. During the smoking process by the user, a large voltage drop occurs. Once the voltage is lower than the over-discharge protection voltage of the lithium battery delay protection circuit, the over-discharge voltage protection power supply will be triggered in advance, and the electronic product will have a state of no output voltage, the product will shut down abnormally and cannot be used, reducing the user experience. Summary of the Utility Model

[0003] The technical problem to be solved in the embodiment of the utility model is to provide a lithium battery delay protection circuit, a battery and an electronic product, so as to solve the problem that in the prior art, the over-discharge protection delay time of the lithium battery delay protection circuit is short, which will trigger the over-discharge voltage protection power supply in advance, resulting in a state of no output voltage in the electronic product, abnormal shutdown of the product and inability to use, reducing the user experience.

[0004] The utility model discloses a lithium battery delay protection circuit, including: a power supply, a resistor R1, a capacitor C1, a chip U1, a MOS transistor Q1 and a capacitor C2. One end of the resistor R1 is connected to the positive pole of the power supply, and the other end is respectively connected to the VDD pin of the chip U1 and one end of the capacitor C1. The other end of the capacitor C1 is connected to the VSS pin of the chip U1, the S1 pin of the MOS transistor Q1 and the negative pole of the power supply. The G1 pin of the MOS transistor Q1 is connected to the DOUT pin of the chip U1, and the G2 pin of the MOS transistor Q1 is connected to the COUT pin of the chip U1; the capacitor C2 is connected between the positive and negative poles of the power supply and is connected in parallel with the capacitor C1.

[0005] Optionally, the lithium battery delay protection circuit further includes: a resistor R2; one end of the resistor R2 is connected to the V- pin of the chip U1, and the other end is connected to the S2 pin of the MOS transistor Q1.

[0006] Optionally, the MOS transistor Q1 is an NMOS.

[0007] Optionally, the chip U1 is a protection IC.

[0008] Optionally, the lithium battery delay protection circuit further includes: an MOS transistor Q2, a control chip U2, and a resistor RS. The S pin of the MOS transistor Q2 is connected to one end of the resistor R1. The G pin of the MOS transistor Q2 is connected to the DO pin of the control chip U2. The D pin of the MOS transistor Q2 is connected to one end of the capacitor C2. The GND of the control chip U2 is grounded. One end of the resistor RS is connected to the S1 pin of the control chip U2 and the other end of the capacitor C2. The other end of the resistor RS is connected to the S2 pin of the control chip U2.

[0009] Optionally, the lithium battery delay protection circuit further includes: a voltage regulator chip U3. The IN pin of the voltage regulator chip U3 is connected to the 1 pin of the MOS transistor Q2. The OUT pin of the voltage regulator chip U3 is connected to the VDD pin of the control chip U2. The GND of the chip U3 is grounded.

[0010] Optionally, the control chip U2 uses an MCU.

[0011] Optionally, the voltage regulator chip U3 uses an LDO.

[0012] The present invention also discloses an electronic product, including the above-mentioned lithium battery delay protection circuit.

[0013] The present invention also discloses an electronic product, including the above-mentioned lithium battery delay protection circuit.

[0014] Compared with the prior art, the beneficial effects of the lithium battery delay protection circuit, battery, and electronic product provided by the embodiments of the present invention are as follows:

[0015] By adding a capacitor C2, the capacitor C2 is connected between the positive and negative electrodes of the power supply and is connected in parallel with the capacitor C1. The capacitance value of the parallel capacitors increases. The RC circuit around the chip U1 has a longer delay time as the capacitance value increases. Through the setting of the capacitor C2, the purpose of increasing the over-discharge voltage protection delay time is achieved. The MOS transistor Q1 and the chip U1 form a conventional lithium battery protection circuit. The MOS transistor Q1 is used to detect whether the power supply voltage is lower than the set value. Once over-discharge is detected, the MOS transistor Q1 will cut off the discharge circuit to prevent the power supply from over-discharging. The chip U1 is responsible for monitoring the power supply state and controlling the execution of the protection function. The lithium battery delay protection circuit, battery, and electronic product of the present invention increase the over-discharge voltage protection delay time, can prevent the over-discharge voltage protection from being triggered in advance due to a large voltage drop of the power supply, abnormal shutdown of the product, and inability to use, and improve the user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The technical solutions of the present invention will be further described in detail below in conjunction with the drawings and embodiments. In the drawings:

[0017] Figure 1 It is the circuit diagram of the lithium battery delay protection circuit provided by the embodiment of the present utility model;

[0018] Figure 2 The charge and discharge current control scenario logic diagram provided by the embodiment of the present utility model;

[0019] Figure 3 The power supply voltage control scenario logic diagram provided by the embodiment of the present utility model.

[0020] Each reference numeral in the figure is as follows:

[0021] 10. Power supply. Specific embodiments

[0022] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments may be combined with each other. Now, in conjunction with the drawings, the preferred embodiments of the present utility model will be described in detail.

[0023] The embodiment of the present utility model provides a lithium battery delay protection circuit, as Figure 1 shown, a power supply 10, a resistor R1, a capacitor C1, a chip U1, a MOS transistor Q1 and a capacitor C2. One end of the resistor R1 is connected to the positive pole of the power supply 10, and the other end is respectively connected to the VDD pin of the chip U1 and one end of the capacitor C1. The other end of the capacitor C1 is connected to the VSS pin of the chip U1, the S1 pin of the MOS transistor Q1 and the negative pole of the power supply 10. The G1 pin of the MOS transistor Q1 is connected to the DOUT pin of the chip U1, and the G2 pin of the MOS transistor Q1 is connected to the COUT pin of the chip U1; the capacitor C2 is connected between the positive and negative poles of the power supply 10 and is connected in parallel with the capacitor C1.

[0024] In this embodiment, by adding the capacitor C2, which is connected between the positive and negative poles of the power supply 10 and is connected in parallel with the capacitor C1, the capacitance value of the parallel capacitors increases. As the capacitance value of the RC circuit around the chip U1 (protection IC) increases, the delay time is lengthened. Through the setting of the capacitor C2, the purpose of increasing the over-discharge voltage protection delay time is achieved. The MOS transistor Q1 and the chip U1 form a conventional lithium battery protection circuit. The MOS transistor Q1 is used to detect whether the voltage of the power supply 10 is lower than the set value. Once over-discharge is detected, the MOS transistor Q1 will cut off the discharge circuit to prevent over-discharge of the power supply 10; the chip U1 (protection IC) is responsible for monitoring the state of the power supply 10 and controlling the execution of the protection function. The lithium battery delay protection circuit and electronic product of the present utility model increase the over-discharge voltage protection delay time, can prevent the over-discharge voltage protection from being triggered in advance due to a large voltage drop of the power supply 10, abnormal shutdown of the product and inability to use, and improve the user experience.

[0025] In this embodiment, the over-discharge voltage protection delay time added can be calculated according to the RC formula. The resistor R1 and the capacitor C1 are fixed values, and the over-discharge voltage protection delay time increases with the increase of the capacitance value of the capacitor C2. Therefore, the capacitor C2 can be adjusted adaptively according to different application environments, and no specific limitation is made here.

[0026] The above MOS transistor Q1 uses an existing device: NMOS.

[0027] The above chip U1 uses an existing device: protection IC.

[0028] As a preferred solution of this embodiment, the lithium battery delay protection circuit further includes: a resistor R2; one end of the resistor R2 is connected to the V- pin of the chip U1, and the other end of the resistor R2 is connected to the S2 pin of the MOS transistor Q1.

[0029] Among them, setting the resistor R2 plays a role in current limiting to protect the lithium battery delay protection circuit.

[0030] As a preferred solution of this embodiment, the lithium battery delay protection circuit further includes:

[0031] A MOS transistor Q2, a control chip U2, and a resistor RS. The S pin of the MOS transistor Q2 is connected to one end of the resistor R1, the G pin of the MOS transistor Q2 is connected to the DO pin of the control chip U2, the D pin of the MOS transistor Q2 is connected to one end of the capacitor C2, the GND of the control chip U2 is grounded, one end of the resistor RS is connected to the S1 pin of the control chip U2 and the other end of the capacitor C2, and the other end of the resistor RS is connected to the S2 pin of the control chip U2.

[0032] Among them, the S1 and S2 pins of the control chip U2 are used to detect the charging and discharging current of the power supply 10, and the real-time state of the power supply 10 is judged by the voltage between the S1 and S2 pins of the control chip U2. Specifically, through the set resistor RS, for example:

[0033] The resistance value of the resistor RS is 5mΩ. When the power supply 10 is in the charging state, the voltage is positive, and the minimum charging current is 1A. Then, when it is set that VRs≥0.005V, the DO pin of the control chip U2 is at a high level. At this time, the MOS transistor Q2 is not turned on, and the delay protection circuit does not take effect.

[0034] When the power supply 10 is in the static state, the maximum discharge current <1A, and the voltage of the resistor RS is 0 or negative. Then, when it is set that VRS > -0.005V, the DO pin of the control chip U2 is at a high level. At this time, the MOS transistor Q2 is not turned on, and the delay protection circuit does not take effect.

[0035] When the power supply 10 is discharging at a high current and high rate, the voltage of the resistor RS is negative, and the discharge current ≥ 4A. When VRS ≤ -0.02V is set, at the same time, by controlling the Vbat pin and GND pin of the control chip U2, the voltage of the power supply 10 can be detected in real time;

[0036] When Vbat ≥ 3.6V, the number of high-current and high-rate discharges is unlimited. The DO pin of the control chip U2 is at a low level, and the MOS transistor Q2 is turned on, then the delay circuit takes effect;

[0037] When 3.3V < Vbat < 3.6V, perform a high-current and high-rate discharge once or for 1s, and transmit it to the host pin to remind the customer to charge;

[0038] When Vbat ≤ 3.3V, stop discharging. The DO pin of the control chip U2 is at a high level, the MOS transistor Q2 is not turned on, and the delay protection circuit does not take effect.

[0039] In this embodiment, the control circuit composed of the MOS transistor Q2, the control chip U2, and the resistor RS judges the charging, discharging, and static states, which can better distinguish the usage scenarios, and can not only meet the usage requirements of extending the high-current and high-rate discharge of the large power supply 10, but also ensure the storage time of the power supply 10 / electronic product during long-term transportation or long-term placement.

[0040] The lithium battery delay protection circuit of this embodiment can distinguish different usage scenarios of the power supply 10, fully guarantee the storage performance and conventional safety performance. At the same time, the circuit has few peripheral devices, simple design, and high reliability.

[0041] In this embodiment, the control chip U2 uses an existing device: MCU.

[0042] The resistance value of the above resistor RS can be adjusted according to the actual application situation. At the same time, the setting of the value of the power supply 10 voltage Vbat can be adjusted according to the actual product application situation. Only an example is given here, and no specific limitation is made on this.

[0043] As a preferred solution of this embodiment, the lithium battery delay protection circuit further includes: a voltage regulator chip U3;

[0044] The IN pin of the voltage regulator chip U3 is connected to the 1 pin of the MOS transistor Q2, the OUT pin of the voltage regulator chip U3 is connected to the VDD pin of the control chip U2, and the GND of the chip U3 is grounded.

[0045] Among them, the voltage regulator chip U3 is a voltage regulator, which can protect the circuit from damage and improve the performance and reliability of the entire system.

[0046] In this embodiment, the voltage regulator chip U3 uses an existing device: LDO.

[0047] The embodiment of the present application also discloses a battery, which includes the lithium battery delay protection circuit in the foregoing embodiment. This battery has the same structure and beneficial effects as the lithium battery delay protection circuit in the foregoing embodiment. The structure and beneficial effects of the lithium battery delay protection circuit have been described in detail in the foregoing embodiment and will not be elaborated herein.

[0048] The embodiment of the present application further discloses an electronic product, which includes the lithium battery delay protection circuit in the foregoing embodiment. This electronic product has the same structure and beneficial effects as the lithium battery delay protection circuit in the foregoing embodiment. The structure and beneficial effects of the lithium battery delay protection circuit have been described in detail in the foregoing embodiment and will not be elaborated herein.

[0049] In actual application, the above-mentioned lithium battery delay protection circuit can be integrated on a circuit board, and can be made into a protection control unit as a part of an electronic product. Of course, it can also be made into a protection board as a part of a battery, and no specific limitation is made here. Since the size of the battery protection board is small and the space limitation is large, it is more likely to be displayed on an electronic product.

[0050] It should be understood that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. For those skilled in the art, the technical solutions recorded in the above embodiments can be modified, or some of the technical features can be equivalently replaced; and all such modifications and replacements should fall within the protection scope of the appended claims of the present invention.

Claims

1. A lithium battery delay protection circuit, characterized in that: include: A power supply, a resistor R1, a capacitor C1, a chip U1, a MOS tube Q1 and a capacitor C2, wherein one end of the resistor R1 is connected to the positive electrode of the power supply, and the other end is respectively connected to the VDD pin of the chip U1 and one end of the capacitor C1, the other end of the capacitor C1 is connected to the VSS pin of the chip U1, the S1 pin of the MOS tube Q1 and the negative electrode of the power supply, the G1 pin of the MOS tube Q1 is connected to the DOUT pin of the chip U1, and the G2 pin of the MOS tube Q1 is connected to the COUT pin of the chip U1; The capacitor C2 is connected between the positive and negative electrodes of the power supply and is connected in parallel with the capacitor C1.

2. The lithium battery delay protection circuit according to claim 1, characterized in that: The lithium battery delay protection circuit also includes: a resistor R2; One end of the resistor R2 is connected to the V-pin of the chip U1 , and the other end is connected to the S2 pin of the MOS tube Q1 .

3. The lithium battery delay protection circuit according to claim 1, characterized in that: The MOS tube Q1 is an NMOS.

4. The lithium battery delay protection circuit according to claim 1, characterized in that: The chip U1 adopts a protection IC.

5. The lithium battery delay protection circuit according to claim 2, characterized in that: The lithium battery delay protection circuit also includes: MOS tube Q2, control chip U2 and resistor RS, the S pin of the MOS tube Q2 is connected to one end of the resistor R1, the G pin of the MOS tube Q2 is connected to the DO pin of the control chip U2, the D pin of the MOS tube Q2 is connected to one end of the capacitor C2, the GND of the control chip U2 is grounded, one end of the resistor RS is connected to the S1 pin of the control chip U2 and the other end of the capacitor C2, and the other end of the resistor RS is connected to the S2 pin of the control chip U2.

6. The lithium battery delay protection circuit according to claim 5, characterized in that: The lithium battery delay protection circuit also includes: a voltage stabilizing chip U3; The IN pin of the voltage stabilizing chip U3 is connected to the 1 pin of the MOS tube Q2, the OUT pin of the voltage stabilizing chip U3 is connected to the VDD pin of the control chip U2, and the GND of the chip U3 is grounded.

7. The lithium battery delay protection circuit according to claim 6, characterized in that: The control chip U2 adopts MCU.

8. The lithium battery delay protection circuit according to claim 6, characterized in that: The voltage stabilizing chip U3 adopts LDO.

9. A battery, characterized in that: It comprises the lithium battery delay protection circuit as described in any one of claims 1 to 8.

10. An electronic product, characterized in that: It comprises the lithium battery delay protection circuit as described in any one of claims 1 to 8.

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