CN217882881U - Communication equipment lithium battery protection circuit - Google Patents

Abstract

The utility model discloses a communication equipment lithium battery protection circuit relates to battery circuit technical field, including IC and MOS, IC ' S DO pin and CO pin respectively with MOS ' S G2 and G1 pin series connection, MOS ' S S2 and S1 pin series connection insert to the negative pole circuit in the charging and discharging circuit in, IC ' S VM pin series connection has resistance, resistance parallel access to the negative pole circuit in, IC ' S VDD pin series connection has resistance, resistance parallel access to the positive polar circuit in the charging and discharging circuit in, it has FUSE to establish ties in the positive polar circuit in the charging and discharging circuit. The utility model discloses a set up IC and MOS, carry out effectual protection to charge-discharge circuit, increase FUSE in the circuit simultaneously, protection circuit board and FUSE accomplish in coordination, the voltage of keeping watch on electric core and the electric current of charge-discharge circuit, the break-make in time control current return circuit, thereby battery overcharge appears in the use in better protection product, thereby it leads to burning out phenomenon increase of service life in the overdischarge and overflowing, reduces the cost of scrapping.

Description

Communication equipment lithium battery protection circuit

Technical Field

The utility model relates to a battery circuit technical field, concretely relates to communication equipment lithium cell protection circuit.

Background

The lithium battery is a primary battery using lithium metal or lithium alloy as a negative electrode material and using a non-aqueous electrolyte solution, unlike a lithium ion battery, which is a rechargeable battery, and a lithium ion polymer battery. The inventor of lithium batteries was edison. Because the chemical characteristics of lithium metal are very active, the lithium metal has very high requirements on the environment in processing, storage and use. Therefore, lithium batteries have not been used for a long time. With the development of microelectronic technology at the end of the twentieth century, miniaturized devices are increasing, and high requirements are made on power supplies. The lithium cell has got into large-scale practical stage thereupon, all uses the lithium cell in a lot of intelligent homes.

Lithium batteries are widely used in various communication devices, but because the materials of the lithium batteries determine that the lithium batteries cannot be overcharged, overdischarged, overcurrent and short-circuited, the performance and the service life of the batteries are seriously affected without protection, and a large amount of gas is possibly generated, so that the internal pressure of the batteries is rapidly increased and then the batteries explode to cause safety problems, and the service life of the communication devices is affected.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a communication equipment lithium cell protection circuit to solve the above-mentioned weak point among the prior art.

In order to achieve the above object, the present invention provides the following technical solutions: a kind of protective circuit of lithium battery of communication equipment, including IC and MOS, DO pin and CO pin of IC are connected with G2 and G1 pin of MOS in series separately, S2 and S1 pin of MOS are connected into the negative pole circuit in the charging and discharging circuit in series, VM pin of IC is connected with the resistance in series, the resistance is connected into the negative pole circuit in parallel, VDD pin of IC is connected with the resistance in series, the resistance is connected into the positive pole circuit in the charging and discharging circuit in parallel, VSS pin of IC is connected into the negative pole circuit in parallel, the positive pole circuit in the charging and discharging circuit is connected with FUSE in series, the positive pole circuit and negative pole circuit in the charging and discharging circuit are connected with the zener diode in parallel, VC pin of IC is connected with the temperature measuring transducer, and the resistance is connected with the temperature measuring transducer in series, the capacitance is connected into the VDD pin of IC and the negative pole circuit in parallel, VC pin of IC and the negative pole circuit are connected with the capacitance in parallel.

In the technical scheme, the utility model provides a technological effect and advantage:

the utility model discloses a set up IC and MOS, carry out effectual protection to charging and discharging circuit, the protective battery effect that whole circuit and component all played, thereby prevent that the battery from taking place abominable damage in the use, increase FUSE in the circuit simultaneously, protective circuit board and FUSE accomplish in coordination, the electric current in the electric core of the supervision of constantly accuracy under-40 ℃ to +85 ℃ of the environment, in time control current return circuit's break-make, FUSE prevents under high temperature environment that the battery from taking place abominable damage, thereby the life of better protective battery extension communications facilities, reduce the cost of scrapping.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required to be used in the embodiments will be briefly described below, it is obvious that the drawings in the following description are only some embodiments described in the present invention, and other drawings can be obtained by those skilled in the art according to these drawings.

Fig. 1 is a schematic circuit diagram of the present invention.

Fig. 2 is a schematic diagram of the circuit state in the normal state of the present invention.

Fig. 3 is a schematic diagram of the circuit state in the overcharge protection state of the present invention.

Fig. 4 is a schematic diagram of the circuit state of the over-discharge protection state and the over-current protection state of the present invention.

Fig. 5 is a schematic diagram of the short-circuit protection state of the present invention.

Fig. 6 is an IC schematic diagram of the present invention.

Fig. 7 is a schematic diagram of a MOS of the present invention.

Description of the reference numerals:

u1 is IC (chip), Q1 is MOS (transistor), F1 is FUSE (FUSE), D3 is zener diode, R1, R2 and R3 are resistances, C1 and C2 are capacitances, BM is temperature measurement sensor.

Detailed Description

In order to make the technical solution of the present invention better understood by those skilled in the art, the present invention will be further described in detail with reference to the accompanying drawings.

The utility model provides a communication equipment lithium battery protection Circuit as shown in figure 1, including IC U1 and MOS Q1, wherein IC shows (Integrated Circuit), the MOS is metal (metal) -oxide (oxide) -semiconductor (semiconductor) field effect transistor, in the Circuit field, substitute to indicate with IC and MOS respectively, IC U1 'S DO pin and CO pin respectively with MOS Q1' S G2 and G1 pin series connection, MOS Q1 'S S2 and S1 pin series connection insert to the negative pole Circuit in the charge-discharge Circuit in, IC U1' S VM pin series connection has resistance R3, resistance R3 parallel connection inserts to the negative pole Circuit in, IC U1 'S VDD pin series connection has resistance R1, resistance R1 inserts to the positive pole Circuit in the charge-discharge Circuit in parallel, IC U1' S VSS pin parallel connection inserts to the negative pole Circuit in, series connection has FUSE F1 in the positive pole Circuit in the charge-discharge Circuit, and FUSE represent the FUSE in the Circuit field, indicate in the whole text, indicate to insert to have between this practical U1 and VC 3 to insert to the negative pole Circuit between the direct charge-discharge Circuit and VC 3 VC parallel connection have VC 3 to insert to the VC parallel connection has VC 3 to the negative pole Circuit between the parallel connection of the positive pole Circuit.

Wherein, the utility model discloses in use the components and parts material as follows:

the IC adopts an S-8252AAD-M6T 1U-shaped chip, and the IC judges by sampling the battery voltage; the MOS adopts an FC4B22070L type transistor, the MOS manages the battery cell, and the protection board circuit mainly plays a role of switching.

The FUSE, i.e. the FUSE, is selected from 1206T 8A 63V type FUSE (to prevent unsafe large current and high-temperature discharge).

R1 and R2 are reference supply resistors, and R3 is an overcurrent and detection resistor. C1 and C2 play a role in instantaneous voltage stabilization and filtering.

The utility model discloses a circuit has overcharge protect function, overdischarge protect function overcurrent protection function and short-circuit protection function, and during the circuit normal condition, as shown in fig. 2, IC U1's "CO" and "DO" pin all export the high level in the circuit under normal condition, and two MOSFET all are in the on-state, and the battery can freely charge and discharge.

The overcharge protection function is a function of prohibiting a charger from continuing charging when a certain voltage (hereinafter, referred to as overcharge detection voltage) is reached. Namely, the MOS Q1 for controlling the overcharge is switched into a turn-off state, and the charging is stopped; in the overcharge protection state, as shown in fig. 3, when the control IC detects that the battery voltage reaches 4.28V, the "CO" pin of the control IC changes from high voltage to zero voltage, so that G1 and S1 change from on to off, thereby cutting off the charging loop, and the charger cannot charge the battery any more, thereby performing the overcharge protection function.

The overdischarge protection function is that when the voltage of the battery becomes low, the discharge to the load is stopped, the MOS Q1 for controlling the overdischarge enters a turn-off state, and the discharge is prohibited, the process is just opposite to the action during the overcharge detection, when the overdischarge protection state is shown in fig. 4, when the control IC detects that the voltage of the battery is lower than 2.85V, the DO pin is changed from high voltage to L low level, so that G1 and S1 are changed from on to off, the discharge loop is cut off, the battery can not discharge to the load any more, and the overdischarge protection function is realized (when any one stage of protection fails, the protection board can be continuously operated by the remaining one stage of protection circuit).

The over-current protection function is to stop discharging the load when consuming large current, and the purpose of the function is to protect the battery and the MOS tube, ensure the safety of the battery in the working state, and after the over-current detection, the battery is recovered to the normal state after being separated from the load, and can be recharged or discharged; in an overcurrent protection state, as shown in fig. 4, when the battery discharges the load normally, and the discharge current passes through 2 MOSFETs connected in series, a voltage is generated at both ends of the MOSFET due to the on-resistance of the MOSFET, and the voltage value is detected by the "VM" pin on the control IC U1, if the load is abnormal for some reason, the loop current is increased, and when the loop current is so large that U is greater than 0.150V, the "DO" pin is changed from a high voltage to a zero voltage, so that G2 and S2 are turned from on to off, thereby cutting off the discharge loop, making the current in the loop zero, and playing an overcurrent protection role.

The principle of the short-circuit protection function is the same as that of the overcurrent protection function, as shown in fig. 5, when the battery discharges to the load, if the loop current is so large that U is greater than 0.5V, the control IC U1 determines that the load is short-circuited, and the "DO" pin of the control IC U1 is rapidly changed from high voltage to zero voltage, so that G2 and S2 are switched from on to off, thereby cutting off the discharge loop and playing a role in short-circuit protection.

TABLE 1 correlation test reference data diagram

In summary, the following steps: the charging and discharging circuit is effectively protected by arranging the IC U1 and the MOS Q1, the whole circuit and elements play a role of protecting the battery, so that the battery is prevented from being damaged badly when in use, meanwhile, the FUSE F1 is added in the circuit, the protection circuit board and the FUSE F1 are completed cooperatively, the voltage of the battery core and the current of the charging and discharging loop are accurately monitored constantly under the environment of-40 ℃ to +85 ℃, and the on-off of the current loop is controlled in time; FUSE prevents under high temperature environment that the battery from taking place abominable damage, thereby the better protection product appears the battery overcharge in the use, leads to burning out the phenomenon in overdischarging and overflowing to increase of service life, reduce the cost of scrapping.

While certain exemplary embodiments of the present invention have been described above by way of illustration only, it will be apparent to those of ordinary skill in the art that the described embodiments may be modified in various different ways without departing from the spirit and scope of the present invention. Accordingly, the drawings and description are to be regarded as illustrative in nature and not as restrictive on the scope of the appended claims.

Claims (5)

1. The utility model provides a communication equipment lithium cell protection circuit, includes IC (U1) and MOS (Q1), its characterized in that: the improved battery charging and discharging circuit is characterized in that a DO pin and a CO pin of the IC (U1) are connected with a G2 pin and a G1 pin of the MOS (Q1) in series respectively, an S2 pin and an S1 pin of the MOS (Q1) are connected into a negative pole circuit in the charging and discharging circuit in series, a VM pin of the IC (U1) is connected with a resistor (R3) in series, the resistor (R3) is connected into the negative pole circuit in parallel, a VDD pin of the IC (U1) is connected with a resistor (R1) in series, the resistor (R1) is connected into a positive pole circuit in the charging and discharging circuit in parallel, and FUSE (F1) is connected into the positive pole circuit in the charging and discharging circuit in series.

2. The protection circuit of claim 1, wherein: and a VSS pin of the IC (U1) is connected into a negative circuit in parallel.

3. The protection circuit for lithium battery of communication equipment as claimed in claim 1, wherein: and a voltage stabilizing diode (D3) is connected in parallel between the positive circuit and the negative circuit in the charging and discharging circuit.

4. The protection circuit for lithium battery of communication equipment as claimed in claim 1, wherein: the VC pin of the IC (U1) is connected with a temperature measuring sensor (BE), and a resistor (R3) is connected in series between the temperature measuring sensor (BE) and the pin.

5. The protection circuit of claim 1, wherein: a capacitor (C1) is connected between a VDD pin of the IC (U1) and the negative pole circuit in parallel, and a capacitor (C2) is connected between a VC pin of the IC (U1) and the negative pole circuit in parallel.

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