CN216819458U - Lithium battery protection circuit and protection board - Google Patents
Lithium battery protection circuit and protection board Download PDFInfo
- Publication number
- CN216819458U CN216819458U CN202220028710.5U CN202220028710U CN216819458U CN 216819458 U CN216819458 U CN 216819458U CN 202220028710 U CN202220028710 U CN 202220028710U CN 216819458 U CN216819458 U CN 216819458U
- Authority
- CN
- China
- Prior art keywords
- lithium battery
- electrically connected
- mos tube
- power supply
- battery protection
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Landscapes
- Charge And Discharge Circuits For Batteries Or The Like (AREA)
Abstract
The utility model discloses a lithium battery protection circuit and a protection board, wherein a diode is connected between a discharge switch control pin of a lithium battery protection chip and a power supply anode, when the power supply anode and the power supply cathode are in short circuit, the level of the discharge switch control pin of the lithium battery protection chip can be rapidly pulled down to the level of the power supply cathode and the voltage drop of the diode, which is smaller than the starting voltage of a discharge MOS (metal oxide semiconductor) tube, the discharge MOS tube can be forcibly closed at the moment, and then the lithium battery protection chip normally carries out short circuit protection.
Description
Technical Field
The utility model relates to the technical field of lithium battery protection, in particular to a lithium battery protection circuit and a protection board.
Background
In recent years, lithium battery packs are widely applied, when the lithium battery packs are used, a lithium battery protection circuit needs to be used for charge and discharge management, and the lithium battery protection circuit needs to have high-power discharge current (40-50A) and a quick short-circuit protection function.
As shown in fig. 1, a lithium battery protection circuit in the prior art generally samples a discharge current of a lithium battery pack through a current sampling pin CS of a lithium battery protection chip to determine whether a short circuit occurs between a power supply positive electrode PB + and a power supply positive electrode PB —, but the lithium battery protection circuit also has the following disadvantages:
if the discharge MOS tube M1 adopts an MOS tube with high internal resistance, the discharge current of the lithium battery pack during normal discharge is too low, and if the discharge MOS tube M1 adopts an MOS tube with low internal resistance, although the discharge current of the lithium battery pack during normal discharge can be increased, the protection threshold value of the lithium battery pack for short-circuit protection of the lithium battery pack is correspondingly increased, so that the lithium battery pack can not respond quickly when short circuit really occurs, and a circuit board and a lead are easily burnt;
meanwhile, due to the existence of R1 and C1, the residual voltage can continuously supply power to the lithium battery protection chip during short circuit, so that the level of the OD pin of the lithium battery protection chip cannot immediately turn off the discharge MOS transistor M1, and a burnout fault can also occur.
SUMMERY OF THE UTILITY MODEL
The utility model provides a lithium battery protection circuit and a protection board, which have high response speed when a lithium battery pack is short-circuited and can continuously perform short-circuit protection.
In order to solve the above technical problem, the lithium battery protection circuit provided by the present invention comprises:
a lithium battery pack;
the power supply positive electrode is electrically connected with the positive electrode of the lithium battery pack;
a power supply cathode;
the lithium battery protection chip is provided with a discharge switch control pin and a charge switch control pin;
the grid electrode of the discharge MOS tube is electrically connected with a discharge switch control pin of the lithium battery protection chip, and the source electrode of the discharge MOS tube is electrically connected with the negative electrode of the lithium battery pack;
the grid electrode of the charging MOS tube is electrically connected with a charging switch control pin of the lithium battery protection chip, the source electrode of the charging MOS tube is electrically connected with the power supply cathode, and the drain electrode of the charging MOS tube is electrically connected with the drain electrode of the discharging MOS tube;
and the anode of the diode is electrically connected with a discharge switch control pin of the lithium battery protection chip, and the cathode of the diode is electrically connected with the power supply anode.
In order to solve the above technical problem, the present invention further provides another lithium battery protection circuit, including:
a lithium battery pack;
the power supply positive electrode is electrically connected with the positive electrode of the lithium battery pack;
the power supply negative electrode is electrically connected with the negative electrode of the lithium battery pack;
the charging module is used for charging the lithium battery pack and is provided with a charging negative electrode;
the lithium battery protection chip is provided with a discharge switch control pin, a charge switch control pin and a current sampling pin, and the current sampling pin is electrically connected with the power supply cathode;
the grid electrode of the discharge MOS tube is electrically connected with a discharge switch control pin of the lithium battery protection chip, the source electrode of the discharge MOS tube is grounded, and the drain electrode of the discharge MOS tube is electrically connected with the power supply cathode;
the grid electrode of the charging MOS tube is electrically connected with a charging switch control pin of the lithium battery protection chip, the source electrode of the charging MOS tube is electrically connected with the drain electrode of the discharging MOS tube, and the drain electrode of the charging MOS tube is electrically connected with the charging cathode;
and the anode of the diode is electrically connected with a discharge switch control pin of the lithium battery protection chip, and the cathode of the diode is electrically connected with the power supply anode.
In order to solve the technical problem, the utility model further provides a protection board, which comprises a PCB, wherein a protection circuit is manufactured on the PCB, and the protection circuit is the lithium battery protection circuit.
After adopting the structure, compared with the prior art, the utility model has the following advantages:
in the utility model, a diode is connected between a discharge switch control pin of a lithium battery protection chip and a power supply positive electrode, when the power supply positive electrode and the power supply negative electrode are in short circuit, the level of the discharge switch control pin of the lithium battery protection chip can be rapidly reduced to the level of the power supply negative electrode plus the voltage drop of the diode, which is less than the starting voltage of a discharge MOS tube, the discharge MOS tube can be forcibly closed, once the discharge MOS tube is closed, a discharge circuit of a lithium battery pack is disconnected, and the short-circuit fault is removed, so that when the short circuit occurs, the lithium battery pack can respond quickly to forcibly disconnect the discharge MOS tube without waiting for the instruction of the lithium battery protection chip, and the response speed is higher when the lithium battery pack is in short circuit.
After the discharging MOS tube is forcibly closed, the voltage of the current sampling pin of the lithium battery protection chip is pulled up to the power supply voltage (7.4-8.4V) of the lithium battery pack, at the moment, the lithium battery protection chip can work normally again, the lithium battery protection chip controls the level of the discharging switch control pin so that the discharging MOS tube is always kept in a closed state, the whole system enters a very stable working state, and the purpose of continuous short-circuit protection is achieved.
Drawings
FIG. 1 is a schematic diagram of a lithium battery protection circuit in the prior art;
fig. 2 is a schematic structural diagram of a lithium battery protection circuit according to a first embodiment of the present invention;
fig. 3 is a schematic structural diagram of a lithium battery protection circuit according to a second embodiment of the present invention.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.
The first embodiment,
As shown in fig. 2, the lithium battery protection circuit of this embodiment includes a lithium battery pack, a positive power supply electrode PB +, a negative power supply electrode PB —, a lithium battery protection chip, a discharge MOS transistor M1, a charge MOS transistor M2, a diode D1, a resistor R1, a capacitor C1, a resistor R2, and a capacitor C2.
Lithium battery protection chip has the VDD pin, VC pin and VSS pin, the one end of resistance R1 is connected with the positive pole electricity of lithium cell group, the other end of resistance R1 is connected with the VDD pin electricity of lithium battery protection chip, the one end of electric capacity C1 is connected with the VDD pin electricity of lithium battery protection chip, the other end ground connection of electric capacity C1, the one end of resistance R2 is connected with the center tap electricity of lithium cell group, the other end of resistance R2 is connected with the VC pin electricity of lithium battery protection chip, the one end of electric capacity C2 is connected with the VC pin electricity of lithium battery protection chip, the other end ground connection of electric capacity C1.
And the power supply positive electrode PB + is electrically connected with the positive electrode of the lithium battery pack.
The lithium battery protection chip is provided with a discharge switch control pin OD, a charge switch control pin OC and a current sampling pin CS, wherein the current sampling pin CS is electrically connected with a power supply negative electrode PB-electrically.
The grid electrode of the discharging MOS tube M1 is electrically connected with a discharging switch control OD pin of the lithium battery protection chip, and the source electrode of the discharging MOS tube M1 is electrically connected with the negative electrode of the lithium battery pack.
The grid electrode of the charging MOS tube M2 is electrically connected with a charging switch control pin OC of the lithium battery protection chip, the source electrode of the charging MOS tube M2 is electrically connected with a power supply cathode PB-, and the drain electrode of the charging MOS tube M2 is electrically connected with the drain electrode of the discharging MOS tube M1.
The anode of the diode D1 is electrically connected with a discharge switch control pin OD of the lithium battery protection chip, and the cathode of the diode D1 is electrically connected with a power supply anode PB-of the lithium battery protection chip.
In this embodiment, the diode D1 is connected between the discharging switch control pin OD of the lithium battery protection chip and the power supply positive electrode PB +, when the power supply positive electrode PB + and the power supply negative electrode PB-are shorted, the level of the discharging switch control pin OD of the lithium battery protection chip is rapidly pulled down to the level of the power supply negative electrode PB-plus the voltage drop of the diode D1, which is about 0.7V, and the turn-on voltage of the discharging MOS transistor M1 is above 1.8V, at this time, the discharging MOS transistor M1 is forcibly turned off, at this time, no matter whether the lithium battery protection chip cannot timely turn off the discharging switch control pin OD due to the existence of the resistor R1 and the capacitor C1, the discharging MOS transistor M1 is forcibly turned off, and once the discharging MOS transistor M1 is turned off, the discharging circuit of the battery pack is turned off, the short-circuit fault is removed, so that, when a short circuit occurs, there is no need to wait for an instruction of the lithium battery protection chip, the discharge MOS tube can be forcibly disconnected by quick response, so that the response speed is higher when the lithium battery pack is short-circuited.
After the discharging MOS tube M1 is forcibly closed, the voltage of the current sampling pin CS of the lithium battery protection chip is pulled up to the power supply voltage (7.4-8.4V) of the lithium battery pack, at the moment, the lithium battery protection chip can work normally again, the lithium battery protection chip controls the level of the discharging switch control pin OD so that the discharging MOS tube M1 is always kept in a closed state, the whole system enters a very stable working state, and the purpose of continuous short-circuit protection is achieved.
After the scheme is adopted, only one discharging MOS tube M1 meeting the requirements is selected at will according to the maximum discharging current index and considering the cost, the influence of the discrete type produced by the discharging MOS tube M1 on the stability of the system is ignored, and the system is very safe and reliable.
Meanwhile, taking the double-lithium battery pack protection plate as an example, the current market price is about 2 yuan. The performance indexes of a plurality of similar products adopting 2 MOS tubes can be achieved by only adopting one discharge MOS tube M1, the cost of one MOS tube is about 0.4 yuan, and the cost advantage is very obvious.
Example II,
As shown in fig. 3, the lithium battery protection circuit of the present embodiment includes a lithium battery pack, a positive power supply electrode P +, a negative power supply electrode P-, a charging module, a lithium battery protection chip U1, a discharging MOS transistor Q1, a charging MOS transistor Q2, and a diode D2.
And the power supply anode P + is electrically connected with the anode of the lithium battery pack.
And the power supply negative electrode P-is electrically connected with the negative electrode of the lithium battery pack.
The charging module is used for charging the lithium battery pack and has a charging cathode C-.
The lithium battery protection chip is provided with a discharge switch control pin DO and a charge switch control pin CO.
The grid electrode of the discharging MOS tube Q1 is electrically connected with a discharging switch control pin DO of the lithium battery protection chip, the source electrode of the discharging MOS tube Q1 is grounded, and the drain electrode of the discharging MOS tube Q1 is electrically connected with a power supply negative electrode P-.
The grid electrode of the charging MOS tube Q2 is electrically connected with a charging switch control pin CO of the lithium battery protection chip, the source electrode of the charging MOS tube Q2 is electrically connected with the drain electrode of the discharging MOS tube Q1, and the drain electrode of the charging MOS tube Q2 is electrically connected with a charging cathode C-.
The anode of the diode D2 is electrically connected with the discharge switch control pin DO of the lithium battery protection chip, and the cathode of the diode D2 is electrically connected with the power supply anode P +.
When the power supply anode P + and the power supply cathode P-are short-circuited, the level of the discharge switch control pin D0 of the lithium battery protection chip U1 is rapidly pulled down to the level of the power supply cathode P-plus the voltage drop of the diode D2, which is about 0.7V, the opening voltage of the discharge MOS tube Q1 is above 1.8V, and the discharge MOS tube Q1 is forcibly closed at the moment, so that the short-circuit fault is relieved, and the protection circuit is not burnt.
In addition, in this embodiment, the drain of the discharging MOS transistor Q1 is directly used as the negative electrode of the lithium battery pack for output, so that the discharging MOS transistor Q1 and the charging MOS transistor Q2 can adopt MOS transistors with different parameters because the discharging current is large and the charging current is small, so that the charging MOS transistor Q2 can adopt a product of about 3A, and the system cost is further reduced.
The utility model further provides a protection board which comprises the PCB, wherein the PCB is provided with a protection circuit, and the protection circuit is the lithium battery protection circuit in the first embodiment or the second embodiment.
The above description is only about the preferred embodiment of the present invention, but it should not be understood as limiting the claims, and the present invention may be modified in other structures, not limited to the above structures. In general, all changes which come within the scope of the utility model as defined by the independent claims are intended to be embraced therein.
Claims (3)
1. A lithium battery protection circuit, comprising:
a lithium battery pack;
the power supply positive electrode is electrically connected with the positive electrode of the lithium battery pack;
a power supply cathode;
the lithium battery protection chip is provided with a discharge switch control pin, a charge switch control pin and a current sampling pin, and the current sampling pin is electrically connected with the power supply cathode;
the grid electrode of the discharge MOS tube is electrically connected with a discharge switch control pin of the lithium battery protection chip, and the source electrode of the discharge MOS tube is electrically connected with the negative electrode of the lithium battery pack;
the grid electrode of the charging MOS tube is electrically connected with a charging switch control pin of the lithium battery protection chip, the source electrode of the charging MOS tube is electrically connected with the power supply cathode, and the drain electrode of the charging MOS tube is electrically connected with the drain electrode of the discharging MOS tube;
and the anode of the diode is electrically connected with a discharge switch control pin of the lithium battery protection chip, and the cathode of the diode is electrically connected with the power supply anode.
2. A lithium battery protection circuit, comprising:
a lithium battery pack;
the power supply positive electrode is electrically connected with the positive electrode of the lithium battery pack;
the power supply negative electrode is electrically connected with the negative electrode of the lithium battery pack;
the charging module is used for charging the lithium battery pack and is provided with a charging negative electrode;
the lithium battery protection chip is provided with a discharge switch control pin and a charge switch control pin;
the grid electrode of the discharge MOS tube is electrically connected with a discharge switch control pin of the lithium battery protection chip, the source electrode of the discharge MOS tube is grounded, and the drain electrode of the discharge MOS tube is electrically connected with the power supply cathode;
the grid electrode of the charging MOS tube is electrically connected with a charging switch control pin of the lithium battery protection chip, the source electrode of the charging MOS tube is electrically connected with the drain electrode of the discharging MOS tube, and the drain electrode of the charging MOS tube is electrically connected with the charging cathode;
and the anode of the diode is electrically connected with a discharge switch control pin of the lithium battery protection chip, and the cathode of the diode is electrically connected with the power supply anode.
3. A protective board comprising a PCB circuit board having a protective circuit formed thereon, wherein the protective circuit is the lithium battery protective circuit as claimed in claim 1 or 2.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202220028710.5U CN216819458U (en) | 2022-01-06 | 2022-01-06 | Lithium battery protection circuit and protection board |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202220028710.5U CN216819458U (en) | 2022-01-06 | 2022-01-06 | Lithium battery protection circuit and protection board |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN216819458U true CN216819458U (en) | 2022-06-24 |
Family
ID=82063198
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202220028710.5U Active CN216819458U (en) | 2022-01-06 | 2022-01-06 | Lithium battery protection circuit and protection board |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN216819458U (en) |
-
2022
- 2022-01-06 CN CN202220028710.5U patent/CN216819458U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107834519B (en) | Lithium battery protection control ASIC chip system | |
| CN111071049A (en) | Voltage output reverse connection prevention circuit | |
| CN112886684A (en) | Multi-lithium battery charging and discharging management circuit and system | |
| CN111900773A (en) | Lithium battery short-circuit protection circuit and method | |
| CN216819458U (en) | Lithium battery protection circuit and protection board | |
| CN114389337A (en) | Lithium battery protection circuit and protection board | |
| CN216086233U (en) | Super capacitor charging and discharging circuit and system | |
| CN112582984B (en) | Quick turn-off circuit and lithium battery protection system thereof | |
| CN213341687U (en) | Intelligent power lithium battery circuit for automobile | |
| CN209313501U (en) | A kind of double cell group parallel connection isolation circuit based on ideal diode | |
| CN201311448Y (en) | Solar cell panel no-load voltage detection circuit | |
| CN201260085Y (en) | Solar energy controller | |
| CN112952924A (en) | Battery management device and electrical apparatus | |
| CN219436645U (en) | Lithium battery integrated protection board | |
| CN214154063U (en) | Charging protection circuit | |
| CN219351310U (en) | Energy storage power supply system | |
| CN215267708U (en) | Battery undervoltage automatic power-off circuit | |
| CN219181218U (en) | Charging circuit of multi-group lithium battery system | |
| CN219678161U (en) | Power supply circuit and photovoltaic energy storage system | |
| CN220107638U (en) | Multi-battery parallel charge-discharge control device | |
| CN211295290U (en) | Overcharge and overdischarge self-protection lithium battery | |
| CN211958845U (en) | Two-section lithium battery protection circuit | |
| CN220914973U (en) | Safety equalization circuit for parallel connection of battery packs | |
| CN219086850U (en) | Overcurrent and short-circuit protection circuit for discharging battery | |
| CN217544712U (en) | Battery pack parallel control circuit |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |