CN209029953U - A kind of charge protector and electronic product - Google Patents

Abstract

The utility model discloses a kind of charge protector and electronic products, and protecting circuit includes OCP/OVP protection circuit, resistance adjustment circuit, control circuit；OCP/OVP protects the power input of circuit to connect power supply, and OCP/OVP protects the power output end of circuit to connect rechargeable battery by the switch ways of first switch circuit；The control terminal of first switch circuit connects control circuit；The power output end of the power input connection OCP/OVP protection circuit of control circuit；Resistance adjustment circuit includes the resistance circuit of at least two-way parallel connection, the thresholding end of one end connection OCP/OVP protection circuit per resistance circuit all the way, other end ground connection；Control circuit is connected in the control terminal of the switch ways for being wherein connected with second switch circuit on resistance circuit all the way, second switch circuit.The utility model guarantees that control circuit normally starts when control circuit is inactive；Current-limiting protection effect is given full play to after control circuit starting.

Description

A kind of charge protector and electronic product

Technical field

The utility model belongs to field of circuit technology, specifically, being to be related to a kind of charge protector and using institute State the electronic product of charge protector design.

Background technique

Currently, safety in production and safe design have spread to every field, audio class product also focuses more on safety Property.Earphone class product is in charging, due to using external power supply to provide energy, if occurring in earphone or product use process abnormal Situation is possible to out when serious if the current versus cell charging excessive in charging is possible to will lead to battery appearance exception Existing bulge and on fire.Therefore, in various battery class products, including earphone class product, OCP can all be increased on charging circuit (Over Current Protection), OVP(Over Voltage Protection) chip, to the voltage and current of charging It is limited.

If being inserted into charging circuit but in system closedown, in the process of system starting moment, each chip and function Module will carry out initial power-on and initialization, the charging of the energy-storage travelling wave tube (such as capacitor, inductance) including various pieces, due to each The charge and discharge of a functional module are very big for the absorption of electric current, and some is even up to several amperes, and due to joined OCP chip pair The limitation that charging circuit electric current carries out, after starting immediate current is excessive, OCP starts protection mechanism, causes system starting abnormal, And then the charge function under off-mode being affected, therefore occur under power down condition on many earphones, earphone cannot charge The case where, and earphone class product has to retain the function of earphone charging in the power-offstate, to guarantee that headset batteries consume completely It can charge under power levels to the greatest extent.Therefore, many chips are in use, it is desirable that do not allow to limit electric current when powering on, but This measure is not inconsistent with safety requirements again.

Summary of the invention

The utility model provides a kind of charge protector, not only ensure that the normal starting of control circuit, but also improves The safety of charging.

In order to solve the above technical problems, the utility model is achieved using following technical scheme:

A kind of charge protector, including OCP/OVP protect circuit, resistance adjustment circuit, control circuit, rechargeable battery； The power input of the OCP/OVP protection circuit connects power supply, and the power output end of the OCP/OVP protection circuit is logical Cross the switch ways connection rechargeable battery of first switch circuit；The control terminal of the first switch circuit connects control circuit；Institute State the power output end of the power input connection OCP/OVP protection circuit of control circuit；The resistance adjustment circuit includes extremely The resistance circuit of few two-way parallel connection, the thresholding end of one end connection OCP/OVP protection circuit per resistance circuit all the way, another termination Ground；In the switch ways for being wherein connected with second switch circuit on resistance circuit all the way, the control terminal of the second switch circuit Connect control circuit.

Further, the first switch circuit includes first switch tube, and the first switch tube is that high conduction voltage drop is opened Guan Guan；The control terminal of the first switch tube connects control circuit, one end connection of the switch ways of the first switch tube OCP/OVP protects the power output end of circuit, and the other end connects rechargeable battery.

Further, the second switch circuit includes second switch and third switching tube, the second switch It is high conduction voltage drop switching tube with third switching tube；The control terminal of the control circuit connection third switching tube, the third One end of the switch ways of switching tube by pull-up resistor connect power supply, the switch ways of the third switching tube it is another End ground connection；The control terminal of one end connection second switch of the switch ways of the third switching tube, the second switch Switch ways are connected on described wherein all the way on resistance circuit.

Further, the resistance adjustment circuit includes the resistance circuit of two-way parallel connection；Wherein resistance circuit all the way One end connects the thresholding end of OCP/OVP protection circuit, and the other end is grounded by the switch ways of second switch.

It further, include a resistance per resistance circuit all the way.

Further, the first switch tube is NMOS tube or NPN triode；When the first switch tube is NMOS tube When, the grid connection control circuit of the first switch tube, the source electrode connection rechargeable battery of the first switch tube, described first The power output end of the drain electrode connection OCP/OVP protection circuit of switching tube；When the first switch tube is NPN triode, institute The base stage connection control circuit of first switch tube is stated, the emitter of the first switch tube connects rechargeable battery, and described first opens Close the power output end of the collector connection OCP/OVP protection circuit of pipe.

Further, the second switch is NMOS tube or NPN triode；When the second switch is NMOS tube When, one end of the switch ways of the grid connection third switching tube of the second switch, the switch of the second switch leads to Road is connected on described wherein all the way on resistance circuit；When the second switch is NPN triode, the second switch Base stage connects one end of the switch ways of third switching tube, the switch ways of the second switch be connected on it is described wherein all the way On resistance circuit.

Further, the third switching tube is NMOS tube or NPN triode；When the third switching tube is NMOS tube When, the grid of the third switching tube connects control circuit, and the drain electrode of the third switching tube is connected by pull-up resistor powers Power supply, the source electrode ground connection of the third switching tube；The control terminal of the drain electrode connection second switch of the third switching tube；Work as institute When to state third switching tube be NPN triode, the base stage of the third switching tube connects control circuit, the collection of the third switching tube Electrode connects power supply, the emitter ground connection of the third switching tube by pull-up resistor；The current collection of the third switching tube The control terminal of pole connection second switch.

Further, the charge protector further includes sampling resistor；One end of the sampling resistor passes through first The power output end of the switch ways connection OCP/OVP protection circuit of switching circuit；The other end connection of the sampling resistor is filled The anode of battery；The anode of the cell voltage input terminal connection rechargeable battery of the control circuit；The electricity of the control circuit Hinder one end of voltage sampling port connection sampling resistor.

Based on the design of above-mentioned charge protector, the utility model also proposed a kind of electronic product, including described Charge protector.

Compared with prior art, the advantages and positive effects of the utility model are as follows: the charge protector of the utility model And electronic product, when control circuit is inactive, OCP/OVP protect circuit cut-off current it is larger, can satisfy circuit it is initial on To the requirement of high current when electric, avoid protecting the current-limiting protection of circuit to lead to upper electrical anomaly due to OCP/OVP, to avoid controlling Circuit start is abnormal, guarantees that control circuit normally starts, and then guarantees normally to charge for rechargeable battery；Start in control circuit Afterwards, OCP/OVP protect circuit cut-off current it is smaller, OCP/OVP protection circuit can give full play to current-limiting protection effect, avoid by In the excessive entire circuit of damage of electric current, the safety of entire circuit and the safety of charging process are improved.

After the detailed description of the utility model embodiment is read in conjunction with the figure, other features and advantages of the utility model It will become clearer.

Detailed description of the invention

Fig. 1 is the circuit block diagram of the one embodiment for the charge protector that the utility model is proposed；

Fig. 2 is the circuit diagram of Fig. 1.

Specific embodiment

Specific embodiment of the present utility model is described in more detail with reference to the accompanying drawing.

The charge protector of the present embodiment mainly includes that OCP/OVP protects circuit, resistance adjustment circuit, control circuit MCU, rechargeable battery Battery etc., it is shown in Figure 1.

OCP/OVP protects power input Vin connection the power supply VBUS_IN, OCP/OVP of circuit to protect the electricity of circuit Source output terminal Vout connects rechargeable battery Battery by the switch ways of first switch circuit；The control of first switch circuit End connection control circuit, control circuit control the on-off of first switch circuit, to control OCP/OVP protection circuit and charging electricity The on-off of charging circuit between pond；The power output end Vout of the power input connection OCP/OVP protection circuit of control circuit, OCP/OVP protects the power supply of circuit output for control circuit power supply；Moreover, rechargeable battery is also control circuit power supply.

Resistance adjustment circuit includes the resistance circuit of at least two-way parallel connection, and one end per resistance circuit all the way connects OCP/ OVP protects the thresholding end limit of circuit, other end ground connection；Wherein second switch circuit is being connected on resistance circuit all the way Switch ways, the control terminal of second switch circuit connect control circuit, and control circuit controls the on-off of second switch circuit, thus Control is connected with the on-off of the resistance circuit of second switch circuit, and then changes the resistance value of entire resistance adjustment circuit, that is, changes Become the resistance value between the thresholding end and ground of OCP/OVP protection circuit, then changes the cut-off current of OCP/OVP protection circuit. The resistance value of resistance adjustment circuit is bigger, and OCP/OVP protects the cut-off current of circuit smaller.If power supply flows into OCP/OVP and protects The current value of the power input of protection circuit is more than cut-off current, then OCP/OVP protects circuit to disconnect, and OCP/OVP protects circuit Power output end not out-put supply.

OCP/OVP protects the resistance value between the thresholding end and ground of circuit bigger (i.e. the resistance value of resistance adjustment circuit is bigger), OCP/OVP protects the cut-off current of circuit smaller.OCP/OVP protects circuit according to the voltage change of thresholding end limit, knows entire The change in resistance of resistance adjustment circuit, to change cut-off current.

Assuming that resistance adjustment circuit includes the resistance circuit of the road N parallel connection, N >=2 are connected on resistance circuit all the way wherein The switch ways of second switch circuit.

Under control circuit inactive state, power supply access: when power supply has just accessed, control circuit is inactive When, the thresholding end of the shutdown of first switch circuit, the conducting of second switch circuit, OCP/OVP protection circuit can pass through any road electricity Resistance circuit ground connection, the resistance value of resistance adjustment circuit are the resistance value after the road N resistance circuit is in parallel.After control circuit starting, control The thresholding end of the shutdown of second switch circuit, OCP/OVP protection circuit cannot be by being connected with the resistance circuit of second switch circuit Ground connection, the resistance value of resistance adjustment circuit are the resistance value after the road N-1 resistance circuit is in parallel.As can be seen that after control circuit starting The resistance value of resistance adjustment circuit when the resistance value ratio control circuit of resistance adjustment circuit is inactive increases, and OCP/OVP is caused to protect The cut-off current of protection circuit becomes smaller.When i.e. control circuit is inactive, the resistance value of resistance adjustment circuit is small, and OCP/OVP protects circuit Cut-off current it is big；After control circuit starting, the resistance value of resistance adjustment circuit is big, and OCP/OVP protects the cut-off current of circuit small, at this time Cut-off current be cut-off current when theoretically charging normal.

Therefore, the charge protector of the present embodiment, when control circuit is inactive, OCP/OVP protects the current limliting of circuit It is worth larger requirement when can satisfy circuit initial power-on to high current, avoids protecting the current-limiting protection of circuit due to OCP/OVP Lead to electrical anomaly, to avoid control circuit starting abnormal, guarantee that control circuit normally starts, and then guarantees normally as charging Battery charging；After control circuit starting, OCP/OVP protects the cut-off current of circuit smaller, and OCP/OVP protection circuit can fill Current-limiting protection effect is waved in distribution, avoids being improved the safety of entire circuit due to the excessive entire circuit of damage of electric current and being filled The safety of electric process.

The charge protector of the present embodiment, before control circuit starting, control second switch circuit conducting, by OCP/ The cut-off current of OVP protection circuit tunes up, and guarantees the starting of control circuit normal table；After control circuit starting, control second is opened Powered-down road shutdown, OCP/OVP protect the cut-off current of circuit smaller, restore cut-off current when charging normal；To solve due to The problem of current-limiting protection of OCP/OVP protection circuit causes control circuit starting abnormal and then can not charge normal.The present embodiment Charge protector, prevent under control circuit off-mode, starting moment because OCP/OVP protection circuit cut-off current it is small due to draw The problem of playing control circuit start failure leads to the phenomenon that charging failure in turn；To realize under control circuit off-mode Starting is normal, while guaranteeing to charge normal, and guarantees the safety of charging.

When the voltage of the power input Vin input of OCP/OVP protection circuit is more than voltage limiting value, OCP/OVP protection electricity Road disconnects, output end vo ut not out-put supply.

After control circuit starting, control first switch circuit conducting guarantees between OCP/OVP protection circuit and rechargeable battery The conducting of charging circuit guarantees normally to charge for rechargeable battery, also guarantees the safety of charging.

In the present embodiment, first switch circuit includes first switch tube Q1, and first switch tube Q1 is that high conduction voltage drop is opened Guan Guan；The control terminal of first switch tube Q1 connects control circuit, and one end of the switch ways of first switch tube Q1 connects OCP/OVP The power output end Vout of circuit is protected, the other end connects rechargeable battery.When control circuit exports high level to first switch tube When the control terminal of Q1, first switch tube Q1 conducting, power supply leads to through the switch of OCP/OVP protection circuit, first switch tube Q1 Road is rechargeable battery charging；When control circuit exports control terminal of the low level to first switch tube Q1, first switch tube Q1 is closed Disconnected, power supply can not charge for rechargeable battery.Realize that OCP/OVP protects circuit and charging electricity by design first switch tube Q1 The on-off of charging circuit between pond, improves the safety of charging；Moreover, structure is simple, the component that uses is less, convenient for taking It builds, is at low cost, being easy to implement.

In the present embodiment, first switch tube Q1 is NMOS tube or NPN triode.When first switch tube Q1 is NMOS tube When, shown in Figure 2, the grid of first switch tube Q1 connects control circuit, and the source electrode of first switch tube Q1 connects rechargeable battery, The power output end Vout of the drain electrode connection OCP/OVP protection circuit of first switch Q1 pipe.When first switch tube is NPN triode When, the base stage of first switch tube Q1 connects control circuit, and the emitter of first switch tube Q1 connects rechargeable battery, first switch tube The power output end Vout of the collector connection OCP/OVP protection circuit of Q1.By the way that first switch tube Q1 is selected as NMOS tube Or NPN triode, not only performance is stable, is convenient for control, but also at low cost.

In the present embodiment, second switch circuit includes second switch Q2 and third switching tube Q3, second switch Q2 It is high conduction voltage drop switching tube with third switching tube Q3；Control circuit connects the control terminal of third switching tube Q3, third switch One end of the switch ways of pipe Q3 passes through pull-up resistor R4 connection power supply, the other end of the switch ways of third switching tube Q3 Ground connection；The control terminal of one end connection second switch Q2 of the switch ways of third switching tube Q3, the switch of second switch Q2 Paths connected in series is described wherein all the way on resistance circuit.

When control circuit exports control terminal of the low level to third switching tube Q3, third switching tube Q3 shutdown；Due to The control terminal of two switching tube Q2 is pulled up resistance R4 and power supply is drawn high, therefore, second switch Q2 conducting, and therefore, OCP/ The thresholding end of OVP protection circuit can be grounded by any road resistance circuit, and the resistance value of resistance adjustment circuit is the road N resistance circuit Resistance value after parallel connection.When control circuit exports control terminal of the high level to third switching tube Q3, third switching tube Q3 conducting, Power supply provides electric current and flows into ground through the switch ways of resistance R4, Q3, and the control terminal of second switch Q2 is pulled low, and second opens Pipe Q2 shutdown is closed, therefore, the thresholding end of OCP/OVP protection circuit cannot connect by being in series with the resistance circuit of second switch Ground, the resistance value of resistance adjustment circuit are the resistance value after the road N-1 resistance circuit is in parallel.Electricity is realized by designing above-mentioned two switching tube The resistance value adjustment for hindering adjustment circuit had both avoided protecting the current-limiting protection of circuit to lead to upper electrical anomaly due to OCP/OVP, to avoid Control circuit starting is abnormal, and then guarantees normally to charge for rechargeable battery；The safety of charging is improved again；Moreover, structure is simple Component that is single, using is less, convenient for building, it is at low cost, be easy to implement.

In the present embodiment, second switch Q2 is NMOS tube or NPN triode.When second switch Q2 is NMOS tube When, shown in Figure 2, one end of the switch ways of the grid connection third switching tube Q3 of second switch Q2, second switch The switch ways of Q2 are connected on described wherein all the way on resistance circuit.It is described when the second switch Q2 is NPN triode One end of the switch ways of the base stage connection third switching tube Q3 of second switch Q2, the switch ways of the second switch Q2 It is connected on described wherein all the way on resistance circuit.By the way that second switch Q2 is selected as NMOS tube or NPN triode, not only property It can stablize, convenient for controlling, and at low cost.

In the present embodiment, third switching tube Q3 is NMOS tube or NPN triode.When third switching tube Q3 is NMOS tube When, shown in Figure 2, the grid of third switching tube Q3 connects control circuit, and the drain electrode of third switching tube Q3 passes through pull-up resistor R4 connection power supply, the source electrode ground connection of third switching tube Q3；The control of the drain electrode connection second switch Q2 of third switching tube Q3 End processed.When third switching tube Q3 is NPN triode, the base stage of third switching tube Q3 connects control circuit, third switching tube Q3 Collector by pull-up resistor R4 connection power supply, the emitter ground connection of third switching tube Q3；The collection of third switching tube Q3 The control terminal of electrode connection second switch Q2.By the way that third switching tube Q3 is selected as NMOS tube or NPN triode, not only property It can stablize, convenient for controlling, and at low cost.

In the present embodiment, resistance adjustment circuit includes the resistance circuit of two-way parallel connection；Wherein the one of resistance circuit all the way The thresholding end of end connection OCP/OVP protection circuit, the other end are grounded by the switch ways of second switch Q2；Another way resistance Circuit is directly connected between the thresholding end and ground of OCP/OVP protection circuit.When second switch Q2 is in the conductive state, electricity Hinder resistance value of the resistance value of adjustment circuit for this two-way resistance circuit after in parallel；When second switch Q2 is in an off state, electricity Hinder the resistance value of the resistance value another way resistance circuit of adjustment circuit.The resistance value ratio Q2 of resistance adjustment circuit when Q2 off state is connected The resistance value of resistance adjustment circuit when state increases.By the way that the resistance circuit of two-way parallel connection is arranged, it was both able to achieve resistance adjustment The adjustment of the resistance value of circuit, then realizes the adjustment of the cut-off current of OCP/OVP protection circuit, and makes circuit structure simply, just In build, it is at low cost, be easy to implement.

In the present embodiment, include a resistance per resistance circuit all the way, be both able to achieve the resistance value of resistance adjustment circuit Adjustment, then realize the adjustment of the cut-off current of OCP/OVP protection circuit, but make the structure of resistance circuit it is simple, convenient for taking It builds, is at low cost, being easy to implement.

For example, resistance adjustment circuit includes the resistance circuit of two-way parallel connection, wherein circuitous resistance includes resistance R3 all the way, separately One end resistance circuit includes resistance R2.It is protected by resistance R3 connection OCP/OVP one end of the switch ways of second switch Q2 The thresholding end of circuit, other end ground connection；The thresholding end of OCP/OVP protection circuit is grounded by resistance R2.As second switch Q2 When conducting, resistance value R=R2//R3 of resistance adjustment circuit；When second switch Q2 shutdown, the resistance value R of resistance adjustment circuit= R2.According to actual needs, cut-off current can be adjusted by changing the value of R3, avoided during startup because OCP/OVP is protected The current limliting of protection circuit and cause starting abnormal.

It is U that OCP/OVP, which protects the threshold voltage of circuit, then OCP/OVP protects cut-off current I=U/R of circuit.When power supply electricity When the current value that source stream enters the power input Vin of OCP/OVP protection circuit is more than cut-off current I, OCP/OVP protects circuit disconnected Open, OCP/OVP protects the power output end Vout of circuit not out-put supply, then control circuit powers off, OCP/OVP protect circuit with Charging circuit between rechargeable battery disconnects.

In the present embodiment, charge protector further includes sampling resistor R1；It is opened by first one end of sampling resistor R1 The power output end Vout of the switch ways connection OCP/OVP protection circuit on powered-down road；The other end connection of sampling resistor R1 is filled The anode of battery；The anode of the cell voltage input terminal VBAT connection rechargeable battery of control circuit；The cathode of rechargeable battery connects The GND of connection control circuit；One end of the resistive voltage sampling end VBAT_Sense connection sampling resistor R1 of control circuit.Control electricity Road can know the pressure difference at the both ends R1, Jin Erke by cell voltage input terminal VBAT and resistive voltage sampling end VBAT_Sense To know the electric current for flowing through R1, so as to control the voltage exported to the control terminal of first switch circuit, to control charging Electric current.

In the present embodiment, control circuit MCU can be selected as CSR8670 chip, and the output end CHG_EXT of CSR8670 connects Connect the control terminal of first switch tube Q1, the control terminal of the output end SMPS_1.8V connection third switching tube Q3 of CSR8670, The power output end Vout of the power input VCHG connection OCP/OVP protection circuit of CSR8670.When CSR8670 is inactive, The output end CHG_EXT and output end SMPS_1.8V of CSR8670 is low level, therefore, Q1 shutdown, Q3 shutdown, Q2 conducting.When After CSR8670 starting, the pin CHG_EXT and pin SMPS_1.8V of CSR8670 exports high level, Q1 conducting, Q3 conducting, Q2 Shutdown.

In the present embodiment, OCP/OVP protects circuit that a variety of over-current over-voltage protection chips can be used and realizes, can also use Component is built, and shutdown access, closing are filled when realizing more than cut-off current in normal charging process and more than voltage limiting value Electricity Functional, the safety accident that may cause with preventing circuit overloads from overheating.For example, it is selected as BQ24314 chip, BQ24314's Threshold voltage U=25V.When second switch Q2 conducting, cut-off current I=U/R=25/ (R2//R3).When second switch Q2 is closed When disconnected, the R2 of cut-off current I=U/R=25/.

After control circuit starting, i.e., control circuit is under normal boot-strap state, whether no matter power supply accesses, control Circuit control Q3 conducting, Q2 shutdown, the R2 of cut-off current I=U/R=25/.

Based on the design of above-mentioned charge protector, the present embodiment also proposed a kind of electronic product, fill including described Electric protection circuit.

By designing the charge protector in electronic product, when the control circuit of electronic product is inactive, Requirement when can satisfy initial power-on to high current, avoid due to OCP/OVP protect circuit current-limiting protection cause to power on it is different Often, to avoid control circuit starting abnormal, guarantee that control circuit normally starts, and then guarantee normally to charge for rechargeable battery； After control circuit starting, OCP/OVP protects the cut-off current of circuit smaller, and OCP/OVP protection circuit can give full play to current limliting Protective effect avoids improving the safety of entire circuit and the peace of charging process due to the excessive entire circuit of damage of electric current Quan Xing improves the safety of electronic product.

Certainly, the above description is not intended to limit the present invention, and the utility model is also not limited to the example above, The variations, modifications, additions or substitutions that those skilled in the art are made in the essential scope of the utility model, It should also belong to the protection scope of the utility model.

Claims (10)

1. a kind of charge protector, it is characterised in that: including OCP/OVP protection circuit, resistance adjustment circuit, control circuit, Rechargeable battery；

The power input of the OCP/OVP protection circuit connects power supply, the power supply output of the OCP/OVP protection circuit End connects rechargeable battery by the switch ways of first switch circuit；The control terminal connection control electricity of the first switch circuit Road；The power output end of the power input connection OCP/OVP protection circuit of the control circuit；

The resistance adjustment circuit includes the resistance circuit of at least two-way parallel connection, and one end per resistance circuit all the way connects OCP/ OVP protects the thresholding end of circuit, other end ground connection；It is logical in the switch for being wherein connected with second switch circuit on resistance circuit all the way The control terminal on road, the second switch circuit connects control circuit.

2. circuit according to claim 1, it is characterised in that: the first switch circuit includes first switch tube, described First switch tube is high conduction voltage drop switching tube；The control terminal of the first switch tube connects control circuit, the first switch The power output end of one end connection OCP/OVP protection circuit of the switch ways of pipe, the other end connect rechargeable battery.

3. circuit according to claim 1, it is characterised in that: the second switch circuit includes second switch and third Switching tube, the second switch and third switching tube are high conduction voltage drop switching tube；

The control terminal of the control circuit connection third switching tube, one end of the switch ways of the third switching tube passes through pull-up Resistance connects power supply, the other end ground connection of the switch ways of the third switching tube；

The control terminal of one end connection second switch of the switch ways of the third switching tube, the switch of the second switch Paths connected in series is described wherein all the way on resistance circuit.

4. circuit according to claim 3, it is characterised in that: the resistance adjustment circuit includes the resistance electricity of two-way parallel connection Road；Wherein the thresholding end of one end connection OCP/OVP protection circuit of resistance circuit, the other end are opened by second switch all the way Close path ground.

5. circuit according to claim 1, it is characterised in that: every resistance circuit all the way includes a resistance.

6. circuit according to claim 2, it is characterised in that: the first switch tube is NMOS tube or NPN triode；

When the first switch tube is NMOS tube, the grid of the first switch tube connects control circuit, the first switch The source electrode of pipe connects rechargeable battery, the power output end of the drain electrode connection OCP/OVP protection circuit of the first switch tube；

When the first switch tube is NPN triode, the base stage of the first switch tube connects control circuit, and described first opens The emitter for closing pipe connects rechargeable battery, the power supply output of the collector connection OCP/OVP protection circuit of the first switch tube End.

7. circuit according to claim 3, it is characterised in that: the second switch is NMOS tube or NPN triode；

When the second switch is NMOS tube, the switch ways of the grid connection third switching tube of the second switch One end, the switch ways of the second switch are connected on described wherein all the way on resistance circuit；

When the second switch is NPN triode, the switch of the base stage connection third switching tube of the second switch is logical The one end on road, the switch ways of the second switch are connected on described wherein all the way on resistance circuit.

8. circuit according to claim 3, it is characterised in that: the third switching tube is NMOS tube or NPN triode；

When the third switching tube is NMOS tube, the grid of the third switching tube connects control circuit, the third switch The drain electrode of pipe connects power supply, the source electrode ground connection of the third switching tube by pull-up resistor；The leakage of the third switching tube The control terminal of pole connection second switch；

When the third switching tube is NPN triode, the base stage of the third switching tube connects control circuit, and the third is opened The collector for closing pipe connects power supply, the emitter ground connection of the third switching tube by pull-up resistor；The third switch The control terminal of the collector connection second switch of pipe.

9. circuit according to any one of claim 1 to 8, it is characterised in that: further include sampling resistor；The sampling electricity One end of resistance connects the power output end that OCP/OVP protects circuit by the switch ways of first switch circuit；The sampling electricity The anode of the other end connection rechargeable battery of resistance；

The anode of the cell voltage input terminal connection rechargeable battery of the control circuit；

One end of the resistive voltage sampling end connection sampling resistor of the control circuit.

10. a kind of electronic product, it is characterised in that: including circuit as claimed in any one of claims 1-9 wherein.