CN210839032U

CN210839032U - GPS locator lithium battery charging and discharging protection circuit

Info

Publication number: CN210839032U
Application number: CN201922444843.1U
Authority: CN
Inventors: 钟义; 曾永健
Original assignee: Dongguan Xingkaitai Electronic Technology Co ltd
Current assignee: Dongguan Xingkaitai Electronic Technology Co ltd
Priority date: 2019-12-28
Filing date: 2019-12-28
Publication date: 2020-06-23
Anticipated expiration: 2029-12-28

Abstract

The utility model discloses a GPS locator lithium battery charge-discharge protection circuit, including the lithium battery charging protection chip, the power end of the lithium battery charging protection chip concatenates the current-limiting protection resistance and is electrically connected with the lithium battery and the power positive pole of the external charger, the earthing terminal of the lithium battery charging protection chip is electrically connected with the negative pole of the lithium battery, a filter capacitor for voltage stabilization and filtering is also arranged between the power end and the earthing terminal of the lithium battery charging protection chip, the charging control port and the discharging control port of the lithium battery charging protection chip are respectively and electrically connected with the grid of the charging control MOS tube and the grid of the discharging control MOS tube of the double-power field effect tube; an overcurrent detection port VM of the lithium battery charging protection chip is connected in series with a current-limiting resistor and is electrically connected with a power supply cathode of an external charger and a source electrode of a charging control M tube; an isolation capacitor is arranged between the source electrode of the charging control MOS tube and the source electrode of the discharging control MOS tube, and the drain electrode of the charging control MOS tube is electrically coupled with the drain electrode of the discharging control MOS tube.

Description

GPS locator lithium battery charging and discharging protection circuit

Technical Field

The utility model belongs to the technical field of the lithium battery protection technique and specifically relates to a GPS locator lithium cell charge-discharge protection circuit.

Background

At present, most portable electronic products all adopt the lithium cell to provide the power supply, because the lithium cell characteristic is comparatively active, require higher to the voltage electric current, if do not carry out charge-discharge management to the lithium cell, can reduce the life of lithium cell, simultaneously, still very easily take place the lithium cell explosion, have huge potential safety hazard.

The existing rechargeable lithium battery is not provided with a protection circuit, so that the safety is poor during charging and discharging, the irreversible damage of the battery core can be caused by overcharge or overdischarge, and the defects of electrolyte decomposition, combustion and even explosion of the lamp can be caused when the rechargeable lithium battery is used at an excessively high temperature. Meanwhile, the existing rechargeable lithium battery cannot be overcharged, overdischarged and overcurrent.

In the related art, a better technical solution for solving the above problems is still lacking.

SUMMERY OF THE UTILITY MODEL

The technical problem of the solution of the utility model is to the defect of existence among the above-mentioned prior art, provide a GPS locator lithium cell charge-discharge protection circuit, thereby in order to solve the problem that charge-discharge protection circuit, lithium cell life are short, poor stability are not established to the lithium cell in the current.

In order to solve the technical problem, the utility model discloses the technical scheme who takes as follows, a GPS locator lithium cell charge-discharge protection circuit, including FH9261 lithium cell charge protection chip U1, FH9261 lithium cell charge protection chip U1's power end VDD concatenates current-limiting protection resistance R1 and the anodal electricity of power of rechargeable lithium cell and external charger is connected, FH9261 lithium cell charge protection chip U1's earthing terminal VSS electricity is connected the negative pole of rechargeable lithium cell, still establish the filter capacitor C1 that is used for steady voltage and filtering between FH9261 lithium cell charge protection chip U1's power end VDD and the earthing terminal VSS, FH9261 lithium cell charge protection chip U1's charge control port CO and discharge control port DO are connected the grid G2 of the charge control MOS pipe of double-power field effect transistor Q1 and the grid G1 of the discharge control MOS pipe respectively; an overcurrent detection port VM of the FH9261 lithium battery charging protection chip U1 is connected in series with a current limiting resistor R2 to be electrically connected with a power supply cathode of an external charger and a source S2 of the charging control MOS tube; an isolation capacitor C2 is arranged between the source S2 of the charging control MOS tube and the source S1 of the discharging control MOS tube, and the drain of the charging control MOS tube is electrically coupled with the drain of the discharging control MOS tube.

As a further elaboration of the above technical solution:

in the above technical solution, the double power fet Q1 is a FH8205A double power fet.

In the above technical solution, the resistance value of the current limiting protection resistor R1 is 100 Ω -200 Ω.

In the above technical solution, the resistance value of the current limiting resistor R2 is 1000 Ω -2000 Ω.

In the above technical solution, the capacitance of the filter capacitor C1 is 0.01 μ F to 1 μ F, and the capacitance of the isolation capacitor C2 is 0.01 μ F to 0.1 μ F.

Compared with the prior art, the utility model has the beneficial effects that the utility model discloses a lithium cell charge-discharge protection circuit protects lithium cell charge-discharge in-process overcharge, overdischarge, overflow and the short circuit through adopting FH9261 lithium cell charge protection chip, through the utility model discloses a protection circuit protects the lithium cell to the stability of extension GPS locator lithium cell, make its life-span extension, reduce cost.

Drawings

Fig. 1 is a schematic circuit diagram of the charge and discharge protection circuit of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

The embodiments described by referring to the drawings are exemplary and intended to be used for explaining the present application and are not to be construed as limiting the present application. In the description of the present application, it is to be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the present application and for simplicity in description, and are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed in a particular orientation, and be operated in a particular manner, and thus should not be considered limiting. Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present application, "a plurality" means two or more unless specifically limited otherwise. In this application, unless expressly stated or limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can include, for example, fixed connections, removable connections, or integral connections; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate. In this application, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may comprise direct contact of the first and second features, or may comprise contact of the first and second features not directly but through another feature in between. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. The first feature being "under", "below" and "beneath" the second feature includes the first feature being directly above and obliquely above the second feature, or merely means that the first feature is at a lesser level than the second feature

Referring to the attached drawing 1, the utility model discloses a lithium cell charge-discharge protection circuit is used for the charge protection of the lithium cell of GPS locator, thereby does not establish charge-discharge protection circuit, lithium cell life weak point, the poor stability's problem with the lithium cell of solving current GPS locator. Referring to fig. 1, the charge and discharge protection circuit for the lithium battery of the GPS locator in this embodiment includes a FH9261 lithium battery charge protection chip U1, a power supply terminal VDD of the FH9261 lithium battery charge protection chip U1 is connected in series with a current-limiting protection resistor R1 and is electrically connected to a positive electrode (B +) of a rechargeable lithium battery and a positive electrode (P +) of an external charger, a ground terminal VSS of the FH9261 lithium battery charge protection chip U1 is electrically connected to a negative electrode (B-) of the rechargeable lithium battery, a filter capacitor C1 for voltage stabilization and filtering is further disposed between the power supply terminal VDD and the ground terminal VSS of the FH9261 lithium battery charge protection chip U1, and a charge control port CO and a discharge control port DO of the FH9261 lithium battery charge protection chip U1 are respectively and electrically connected to a gate G2 of a charge control MOS transistor and a gate G1 of a discharge control MOS transistor of a dual; an overcurrent detection port VM of the FH9261 lithium battery charging protection chip U1 is connected in series with a current limiting resistor R2 to be electrically connected with a power supply cathode of an external charger and a source S2 of the charging control MOS tube; an isolation capacitor C2 is arranged between the source S2 of the charging control MOS tube and the source S1 of the discharging control MOS tube, and the drain of the charging control MOS tube is electrically coupled with the drain of the discharging control MOS tube.

It can be understood that, in order to realize the charge and discharge protection of the lithium battery, the dual-power fet Q1 is a FH8205A dual-power fet, the resistance value of the current-limiting protection resistor R1 is 100 Ω to 200 Ω, preferably 100 Ω, and the resistance value of the current-limiting resistor R2 is 1000 Ω to 2000 Ω, preferably 2000 Ω; the capacitance of the filter capacitor C1 is 0.01-1 muF, preferably 0.1 muF, and the capacitance of the isolation capacitor C2 is 0.01-0.1 muF, preferably 0.1 muF.

It should be noted that, FH9261 lithium battery charging protection chip U1 is the main control of the protection circuit, and when actually protecting charging and discharging, the voltage of the rechargeable lithium battery is sampled first, and then various instructions are sent by judgment, and the double-power field effect transistor Q1 is used for switching control of the charging or discharging process. The following operating states of the protection circuit are explained below:

normal operation of the protection circuit

The FH9261 li battery charging protection chip U1 continuously detects the battery voltage connected between VDD and VSS and the voltage difference between VM and VSS to control charging and discharging. When the voltage of the lithium battery is higher than the over-discharge detection voltage (Vdl) and lower than the over-charge detection voltage (Vcu) and the terminal voltage of the VM is higher than the charge over-current detection Voltage (VCIP) and lower than the discharge over-current detection voltage (Vdip), both the OC port and the OD port of the FH9261 lithium battery charge protection chip U1 output high levels to simultaneously turn on the charge control MOSFET and the discharge control MOSFET, and in this state, both the charge and the discharge can be performed freely.

When the lithium battery is connected for the first time, the lithium battery does not discharge, namely the double-power field effect transistor Q1 just begins to be possibly in a turn-off state, the rechargeable lithium battery is connected with the protection circuit, the double-power field effect transistor Q1 needs to be triggered, the P + and the P-end have output voltage, the short-circuit VM terminal can be selected or the charger is connected, and the protection circuit and the lithium battery can work normally.

Protection circuit overcharge protection

The method comprises the steps that a power supply higher than the voltage of a lithium battery is connected to a P + and a P-, the positive electrode of the power supply is connected with B +, the negative electrode of the power supply is connected with B-, after the power supply is connected, the lithium battery starts to charge, the current direction starts from the positive electrode of the power supply, the current flows through the lithium battery, D1 and a charging control MOS tube to the negative electrode of the power supply (at the moment, the discharging control MOS tube is short-circuited by D1), the FH9261 lithium battery charging protection chip U1 samples the value of the voltage of the lithium battery through a capacitor, when the voltage of the lithium battery reaches 4.425v, the FH9261 lithium battery charging protection chip U1 sends an instruction to enable a port CO to be at a low level, at the moment, the current starts from the positive electrode of the power supply and flows through the lithium battery, D1 and reaches the charging control MOS tube, as the grid electrode of the charging control MOS.

Protective circuit over-discharge protection

After a proper load is connected to the P + and the P-, the lithium battery starts to discharge the current from the anode of the lithium battery to the cathode of the lithium battery through the load, the D2 and the discharge control MOS tube (at this time, the charge control MOS tube is short-circuited by the D2); when the lithium battery discharges to 3.0V, the FH9261 lithium battery charging protection chip U1 samples and sends out an instruction, so that the discharging control MOS tube is cut off, the loop is disconnected, and the lithium battery is protected.

Overcurrent protection of protection circuit

After a proper load is connected to the P + and the P-, the lithium battery starts to discharge the current from the anode of the lithium battery to the cathode of the lithium battery through the load, the D2 and the discharge control MOS tube (at this time, the charge control MOS tube is short-circuited by the D2); when the load is suddenly reduced, the FH9261 lithium battery charging protection chip U1 samples the voltage generated by suddenly increasing the current through the VM pin, and at this moment, the FH9261 lithium battery charging protection chip U1 samples and sends out an instruction, so that the discharging control MOS tube is cut off, the loop is disconnected, and the lithium battery is protected.

Short-circuit protection of protection circuit

After the P + and the P-are connected with an empty load, the lithium battery starts to discharge current, the current flows from the positive electrode of the lithium battery to the negative electrode of the lithium battery through the load, the D2 and the discharge control MOS tube (at this time, the charge control MOS tube is short-circuited by the D2), the FH9261 lithium battery charging protection chip U1 samples the voltage generated by suddenly increasing the current through the VM pin, the FH9261 lithium battery charging protection chip U1 samples and sends out an instruction, the discharge control MOS tube is cut off, the loop is disconnected, and the lithium battery is protected.

The above is not intended to limit the technical scope of the present invention, and any modifications, equivalent changes and modifications made to the above embodiments according to the technical spirit of the present invention are all within the scope of the technical solution of the present invention.

Claims

1. A GPS locator lithium battery charge-discharge protection circuit is characterized by comprising a FH9261 lithium battery charge protection chip U1, wherein a power supply end VDD of the FH9261 lithium battery charge protection chip U1 is connected in series with a current-limiting protection resistor R1 to be electrically connected with a power supply anode of a rechargeable lithium battery and an external charger, a grounding end VSS of the FH9261 lithium battery charge protection chip U1 is electrically connected with a cathode of the rechargeable lithium battery, a filter capacitor C1 for voltage stabilization and filtering is further arranged between the power supply end VDD and the grounding end VSS of the FH9261 lithium battery charge protection chip U1, and a charge control port CO and a discharge control port DO of the FH9261 lithium battery charge protection chip U1 are respectively and electrically connected with a grid G2 of a charge control MOS tube and a grid G1 of a discharge control MOS tube of a double-power field effect tube Q1; an overcurrent detection port VM of the FH9261 lithium battery charging protection chip U1 is connected in series with a current limiting resistor R2 to be electrically connected with a power supply cathode of an external charger and a source S2 of the charging control MOS tube; an isolation capacitor C2 is arranged between the source S2 of the charging control MOS tube and the source S1 of the discharging control MOS tube, and the drain of the charging control MOS tube is electrically coupled with the drain of the discharging control MOS tube.

2. The charging and discharging protection circuit for lithium battery of GPS locator according to claim 1, wherein said double power FET Q1 is FH8205A double power FET.

3. The charging and discharging protection circuit for the lithium battery of the GPS locator according to claim 1, wherein the resistance value of the current limiting protection resistor R1 is 100 Ω -200 Ω.

4. The charging and discharging protection circuit for the lithium battery of the GPS locator according to claim 1, wherein the resistance value of the current limiting resistor R2 is 1000 Ω -2000 Ω.

5. The charging and discharging protection circuit for lithium battery of GPS locator according to claim 1, wherein the capacitance of said filter capacitor C1 is 0.01 μ F-1 μ F, and the capacitance of said isolation capacitor C2 is 0.01 μ F-0.1 μ F.