TW201221984A - Current detecting circuit and battery over-current protection controller - Google Patents

Abstract

The present invention discloses a battery over-current protection controller. The battery over-current protection controller comprises a first pin, a second pin, a third pin and a current detecting circuit. The first pin is coupled to a terminal of the current detecting circuit. The second pin is coupled to a positive terminal of a battery module. The third pin is coupled to a negative terminal of the battery module. The current detecting circuit detects a current value of the battery module whether to over a predetermined current value according to a current detecting signal of a current value which is represented to flow the current detecting circuit. Wherein, the current detecting circuit comprises a reference voltage generation unit, a voltage division unit, and a comparison unit. The reference voltage generation unit is coupled between the second and the third pins to generate a reference voltage. The voltage division unit is coupled to the reference voltage to generate a division voltage signal according to the reference voltage. The comparison unit receives the division voltage signal and the current detecting signal to generate an over-current protecting unit with the current of the battery module over the predetermined current value.

Description

r 201221984 VI. Description of the Invention: [Technical Field] The present invention relates to a current detecting circuit and a battery overcurrent protection controller, in particular to a current detecting circuit with high precision and low temperature drift and a battery overcurrent protection controller . [Prior Art] Please refer to the first figure' for the circuit diagram of the conventional battery overcurrent protection controller. The battery overcurrent protection controller 100 includes a voltage detecting unit U0, a logic control unit 120, and a current detecting circuit 13A. The voltage detecting unit detects the voltage of a battery module 10 to generate a voltage control signal DD. The current detecting circuit 130 detects the current output by the battery module 10 to generate an overcurrent protection signal CC to prevent the battery module 1 from being in an overdischarged state. The logic control unit 120 receives the voltage control signal DD and the overcurrent protection signal cc to thereby control whether a charge and discharge switch 20 is turned on or off. The voltage detecting unit 11() is coupled between the positive terminal of the battery module 10 and the negative terminal thereof. When the voltage of the battery module is too high due to overcharging and is too low due to over-discharge, the voltage control signal DD is outputted. The logic control unit 120 causes the logic control unit 12 to control the charge and discharge switch 2 to prevent the voltage of the battery module 10 from being too high/low. The current detecting circuit 13A includes a reference voltage generating unit REF and a comparing unit 132. The reference voltage generating single toREF is coupled between a first common potential vi and a zero potential (ground) for generating a reference voltage. The comparison unit 132 is coupled between the first common potential V1 and the zero potential, wherein the first common potential VI is the positive terminal of the battery module 10 and the zero potential is the negative terminal of the battery module 10. The comparing unit 132 receives the reference voltage at the non-inverting terminal and the current of the battery module 10 at the inverting terminal flows through the charging and discharging switch to generate a current detecting signal D1, thereby determining whether the current detecting signal Di is greater than the reference. The voltage and the overcurrent protection signal CC are generated when the level of the current detecting signal D1 is lower than the reference voltage. The charge and discharge switch 20 is coupled between the positive terminal of the battery module 10 and a positive terminal 11 of the load. When the battery module 10 is in a state of 4 r 201221984, the charge and discharge switch 20 will remain conductive according to the overcurrent protection signal cc, so that the discharge current of the battery module 10 flows through the charge and discharge switch 2 to the load positive end 11; When the battery module 10 is in an over-discharge state, the charge-discharge on-off 2 〇 will be turned off according to the over-current protection S, so that the battery module 1 〇 stops discharging. However, when the battery module 10 of the battery overcurrent protection controller 100 is constituted by a plurality of battery cells connected in series, the first common potential 乂丨 becomes high. Therefore, the voltage withstand capability of the unit 132 needs to be increased, so that the comparison unit 132 needs to use the voltage component, thereby affecting the component matching accuracy and the circuit layout area. In addition, the reference voltage generated by the reference voltage generating unit REF of the prior art may also cause a change in the reference voltage due to the influence of the temperature change, which may cause the comparison unit 132 to be inaccurately broken or even damage the battery module. SUMMARY OF THE INVENTION In view of the fact that the reference voltage in the prior art is susceptible to temperature sensing, the circuit is inaccurate and the circuit is connected to the battery module of the battery, which in turn causes the comparator to increase the withstand voltage capability. Therefore, the present invention utilizes a voltage dividing method to reduce the voltage drift caused by the temperature change of the reference voltage, so that the current detecting circuit has better precision. At the same time, the comparator uses the reference voltage as the driving voltage, so that the component with low withstand voltage can be used instead of the component with high withstand voltage. To achieve the above object, the present invention provides a current detecting circuit comprising a reference generating unit, a voltage dividing unit and a comparing unit. The reference voltage generating unit is coupled between a first common potential and a second common potential to generate a reference voltage. One of the common potential and the second common potential of the voltage dividing unit is used to generate a voltage dividing signal. The comparison unit is coupled to the reference, is pressed to receive the power required for the operation, and receives the voltage division signal and a current detection signal representing a current reduction to determine whether the current is greater than a predetermined amount and the current is greater than a predetermined An overcurrent protection signal is generated when the current is flowing. The invention also provides a battery overcurrent protection controller, comprising a first leg 201221984 wide position, a second pin position, a third pin position and a current detecting circuit. The first pin is coupled to one end of the flow detecting circuit, the second pin is coupled to the positive terminal of the battery module, and the third pin is coupled to the negative terminal of the battery module. The current detecting circuit detects whether the battery module exceeds a predetermined current based on a current-sharing signal representing a current flowing through the current gamma circuit. The current detecting circuit comprises a voltage generating unit, a voltage dividing unit and a comparing unit. The reference voltage generating unit is coupled to the second pin and the third pin to generate a reference voltage. The voltage dividing unit is coupled to the reference voltage to generate a voltage dividing signal according to the reference voltage. The comparison unit receives the voltage division signal and the current detection signal for generating an overcurrent protection signal when the current exceeds a predetermined current. The above summary and the following detailed description are exemplary in order to further illustrate the scope of the invention. Other objects and advantages of the present invention will be described in the following description and drawings. [Embodiment] Please, the second figure is a current sensing diagram according to a preferred embodiment of the present invention. The current detecting circuit is based on the current detecting signal D to detect the current represented by the electric & gamma number di, the size of which is more than a predetermined, flow value. The current detecting circuit includes a reference voltage generating unit, a comparison f70 232, and a voltage dividing unit 234. The reference voltage generating unit ref is coupled between: a first-common: potential vi and a second common potential GND (in this embodiment, a zero potential, i.e., ground) to generate a reference voltage 乂2. The voltage dividing unit (10) J is connected to the common 1: bit v and the other end is coupled to the reference voltage v 匕, and the signal sub-unit 234 includes a first impedance of the series impedance V2 divided to reduce the drift of the reference dragon V2 due to R ί the amount. Here, in (4) - the difficult situation is that the first impedance is less than the impedance of the second impedance, so that the partial pressure of the partial pressure 234 is relatively small and a smaller voltage is obtained. Mail 2 -, Ai "Oil as 201221984" Γ required power. The inverting terminal of the comparison unit 232 receives the current detection signal D1 instead of the inverting terminal receives the voltage division signal D2 to determine whether the current detection signal D1 is The current signal BB is generated when the current detection signal di is smaller than the voltage division signal D2. Next, please refer to the third figure for the battery overcurrent protection according to the first preferred embodiment of the present invention. The circuit over-current protection controller 300 uses the current detecting circuit shown in the second figure to determine whether the current outputted by a battery module 1 in a discharged state exceeds a predetermined current. Battery over-current protection control The device 300 includes a voltage detecting unit 31, a logic control unit 320, and a current detecting circuit 330. The voltage detecting unit 310 detects the voltage of the battery module 1 to generate a voltage control signal DD. Electricity 30 is coupled to the positive terminal of the battery module 10, and generates a current detecting signal D according to the current flowing through the current detecting circuit 330. The current detecting circuit 330 receives the current detecting signal D1' through a first pin 3〇1. Whether an overcurrent protection signal ^^ is generated. The logic control unit 320 receives the voltage control signal DD and the overcurrent protection signal cc to control whether a charge and discharge switch is turned on or off. In this embodiment, the charge and discharge switch is current detection. The measuring circuit 30 〇 current detecting circuit 330 includes a reference voltage generating unit, a voltage dividing unit 334 and a comparing unit 332. The reference voltage generating unit φ is coupled between a second pin 302 and a third pin 303. To generate a reference voltage V2, the second pin 302 is coupled to the positive terminal of the battery module 10 and the third pin 3〇3 is coupled to the negative terminal of the battery module 10. The split unit 33 (one end is connected to the second The other side of the pin 302 is connected to the reference voltage V2 to generate a voltage dividing signal D2 according to the reference voltage γ]. The voltage dividing unit 334 includes a first impedance R1 and a second impedance R2 connected in series, and divides the reference voltage V2. Press to lower the reference voltage V2 due to the temperature production The red dragon drift amount is obtained. Here, the impedance of the (fourth)-preferred air impedance R1 is smaller than the impedance of the second impedance R2, so that the partial pressure of the voltage dividing unit 334 is relatively small to obtain a smaller voltage drift amount. The phase difference receiving signal D2 of the comparing unit 332 and the receiving current detecting signal D1 of the inverting terminal are generated when the level of the stream detecting signal D1 is lower than the level of the voltage dividing signal D2, which is generated by 201221984 /α 秘&quot ;it?站r'r'' ...l 丄·, β .-

Having stopped the battery module 1 332 will generate an overcurrent protection signal cc. At this time, the logic means that the charge and discharge switch (ie, the current detecting circuit 3A) is turned off, so that the electric discharge is continuously discharged to prevent the battery module 1 from being damaged due to overcurrent. The voltage debt measuring unit 310 is input between the second pin 3G2 and the third pin 3〇3 to determine whether the voltage of the side battery module 10 is insufficient. When the voltage of the battery module 1 is lower than the -first-pre-voltage value (for example, the battery module ω is in the over-discharge state), the voltage detection unit it 310 outputs the voltage control signal to the logic control unit 320. At this time, the logic control unit 32 controls the charging and discharging switch to stop, so that the battery module p stops discharging continuously to prevent the battery module 1 from being damaged. Next, please refer to the fourth figure, which is a circuit diagram of a battery overcurrent protection control H according to a second preferred embodiment of the present invention. The battery overcurrent protection controller 400, the current detecting circuit shown in the second figure determines whether the current outputted by the battery module 1 in the discharged state exceeds a predetermined current. The battery overcurrent protection controller 400 includes a voltage detecting unit 41, a logic control unit 42A, and a current detecting circuit 430. Compared with the first preferred embodiment shown in the third figure, the battery module 10 of the embodiment includes a plurality of battery cells connected in series.

The Cell 1, Cell 2, Cell 3 ' voltage detecting unit 410 generates a voltage control signal DD based on the voltage DET1 between the battery cells Cel11 and Cell2 and the battery DET2 between the battery cells Cd1 and ω3. A current detecting circuit 40 is connected between the negative terminal of the battery module 10 and a first pin 4〇1, and generates a current detecting signal D1 according to the magnitude of the current flowing through the charging and discharging switch 20. In this embodiment, the current detecting circuit 40 is a resistor. The current detecting circuit 430 receives the current detecting signal D1 through the first pin 401 to determine whether an overcurrent protection signal CC is generated. The logic control unit 420 receives the voltage control signal DD and the overcurrent protection signal CC to control whether a charge and discharge switch is turned on or off. The current detecting circuit 430 includes a reference voltage generating unit REF, a voltage dividing unit 434, and a comparing unit 432. Wherein, the reference voltage generating unit ref 201221984 ί is connected: the first pin 4° 2 and the third pin 4. 3 are connected to the positive end of the battery module 1 by generating a - reference voltage r electric m〇4〇ii The third pin 403 is coupled to the negative terminal of the battery module 10. One of the partial pressure units 434

The other end of Tr is connected to the reference voltage V2 to generate a voltage division signal D2 for the reference voltage ν2 ί. The voltage dividing unit 434 includes one of the first impedances in series; the voltage V2 is divided to reduce the reference voltage V2 to change the voltage drift due to the temperature. Here, the present invention preferably has a first-resistance if, and the second impedance 112 is recorded to make the voltage of the voltage dividing unit 434 relatively small to obtain a smaller voltage drift amount. Comparison unit 432

Receiving: The sub-f signal D2 and the non-inverting terminal receive the current detecting signal D. When the level of the signal D1 is higher than the level of the voltage dividing signal D2, an overcurrent protection signal cc is generated. That is to say, when the current flowing through the current extraction circuit 4 exceeds two predetermined powers, the voltage across the current_circuit 4〇 is greater than the current measurement signal m. ί : The comparison unit 70 432 will generate an overcurrent protection signal. CC. At this time, the logic control unit 420 controls the charge and discharge switch to be turned off, so that the battery module 1 〇 stops continuing to discharge, so as to prevent the battery module 10 from being damaged due to overcurrent. The voltage detecting unit 410 is lightly connected between the second pin 4〇2 and the third pin 403 to detect that the voltage of the battery cells CeU1, Cdl2, and Cdl3 of the battery module 1 is insufficient. The voltage detecting unit 410 outputs a voltage control signal DD to the logic control when any one of the battery cells Cel1, Cell2, and Cell3 is lower than the -first predetermined voltage (for example, the battery cell whose voltage is too low is in an over-discharge state). Unit 420. At this time, the logic control unit 42 〇 controls the charge and discharge switch to be turned off, so that the pool module 10 stops continuing to discharge to avoid damage to the battery unit whose voltage is too low. 0 Next, please refer to the fifth figure, which is a A circuit diagram of a battery overcurrent protection controller of the third preferred embodiment. Compared with the first preferred embodiment shown in the third figure, the battery overcurrent protection controller 5 uses the current detecting circuit shown in the second figure to determine whether the charging current of a battery module 10 exceeds the charging state. a predetermined current. The battery overcurrent protection controller 5 includes a voltage detecting unit 510, a logic control unit 520, and a current detecting circuit 53. <> Voltage Wide 201221984 The detecting unit 510 detects the voltage of the battery module 以A voltage control signal DD is generated. A current detecting circuit 50 is coupled to the battery module 1 and a current detecting unit 536 receives the current detecting circuit 5's high potential terminal through a first pin 5〇1 at the non-inverting terminal. The terminal receives the low potential end of the current detecting circuit 50 (ie, the positive terminal of the battery module 1〇) through a second pin 502 to generate a current detecting according to the potential difference between the first pin 5〇1 and the second pin. Test signal D1. Then, the current detecting circuit 530 receives the current detecting signal D1 to determine whether an overcurrent protection signal CC is generated. The logic control unit 520 receives the voltage control signal DD and the overcurrent protection signal CC to control whether a charge and discharge switch is turned on or off. In this embodiment, the charge and discharge switch is a current detecting circuit 5〇. The current detecting circuit 530 includes a reference voltage generating unit, a voltage dividing unit 534 and a comparing unit 532. The reference voltage generating unit RgF is connected between a second pin 502 and a third pin 503 to generate a reference voltage V2. The second pin 502 is lightly connected to the positive end of the battery module 1 and the third leg is connected to the negative end of the battery module 10. One end of the voltage dividing unit 534 is coupled to the third pin 503 ′ and the other end is coupled to the reference voltage V2 to generate a voltage dividing signal D2 according to the reference voltage V2. The voltage dividing unit 534 includes a first impedance R1 and a second impedance R2 connected in series, and divides the reference voltage V2 to reduce the voltage drift caused by the temperature change of the reference voltage V2. Here, it is preferable that the impedance of the first impedance R1 is smaller than the impedance of the second impedance R2, so that the partial pressure of the voltage dividing unit 534 is relatively small to obtain a smaller voltage drift amount. The anti-inverted terminal receiving voltage dividing signal D2 and the non-inverting terminal receiving current detecting signal di of the comparing unit 532 generate overcurrent protection when the level of the current detecting signal D1 is higher than the level of the voltage dividing signal D2. Signal CC. That is to say, when the current flowing through the current detecting circuit 5 exceeds a predetermined current 'the current detecting circuit 50 has a large span; the voltage value makes the current detecting signal D1 higher than the voltage dividing signal. When the level of D2 is reached, the comparison unit 532 will generate an overcurrent protection signal CC. At this time, the logic control unit 52 〇 controls the charge and discharge switch (i.e., the current detecting circuit 50) to be turned off, so that the battery module 1 〇 stops continuing charging ‘to prevent the battery module 10 from being damaged due to excessive charging current. The voltage detecting unit 510 is coupled to the second pin 5〇2 and the third chat bit 5〇3

10 201221984 The second is to detect whether the voltage of the battery module 10 is overvoltage. When the voltage of the battery module 1 is higher than a second predetermined voltage value (for example, the battery module 10 is in an overcharged state), the voltage detecting unit 510 outputs the voltage control signal DD to the logic control unit 52A. In this f, the logic control unit 520 controls the charge and discharge switch to be turned off, so that the battery module 10 stops charging to avoid damage to the battery module 1〇. As described above, the present invention fully complies with the three requirements of the patent: novelty, progressive industrial utility. The invention has been described above in terms of preferred embodiments, and it is understood by those skilled in the art that the present invention is not intended to limit the scope of the invention. It should be noted that variations and permutations equivalent to those of the embodiments are intended to be included within the scope of the present invention. Therefore, the scope of the invention is defined by the scope of the following claims. [Simple description of the diagram] The first figure is a schematic circuit diagram of a conventional battery overcurrent protection controller. The first diagram is a schematic diagram of a current sensing circuit in accordance with a preferred embodiment of the present invention. The second figure is a circuit diagram of a battery overcurrent protection controller in accordance with a first preferred embodiment of the present invention. Figure 4 is a circuit diagram of a battery overcurrent protection controller in accordance with a second preferred embodiment of the present invention. Figure 5 is a circuit diagram of a battery overcurrent protection controller in accordance with a third preferred embodiment of the present invention. [Main component symbol description] Prior art: - . . . Battery module 10 load positive terminal 11 charge and discharge switch 20 voltage detection unit H0 logic control unit 120

r 201221984 Current detection circuit 130 Electrical comparison unit 132 Pressure control signal DD Overcurrent protection signal CC Reference voltage generation unit REF First common potential VI Current detection signal D1 The present invention: Battery module 10 Charge and discharge switch 20 Current detection circuit 30 40, 50 battery overcurrent protection controller 300, 400, 500 first pin 301, 401, 501 second pin 302, 402, 502 third pin 303, 403, 503 eDonkey detecting unit 310, 410 510 logic control unit 320, 420, 520 current detecting circuit 330, 430, 530 comparing unit 232, 332, 432, 532 voltage dividing unit 234, 334, 434, 534 current detecting unit 536

Reference voltage generating unit REF

Current signal BB

Overcurrent protection signal CC

Voltage control signal DD current detection signal D1 voltage division signal D2

First common potential VI Reference voltage V2 12 r 201221984 Battery unit Cem, Cell2, Cell3 Battery voltage detection signal DET1, DET2 First impedance R1 Second impedance R2

Claims (1)

Guang 201221984 VII. Patent application scope: 1. A current detecting circuit comprising: a reference voltage generating unit coupled between a first common potential and a second common potential for generating a reference voltage; a unit, one end of which is coupled to one of the first common potential and the second common potential to generate a voltage dividing signal; and a comparing unit coupled to the reference voltage to receive power required for operation, and receiving the The partial pressure is reduced to represent the magnitude of the current - the current fine signal is used to break the electricity; the second is the current; the flow is greater than the - current, and an overcurrent protection signal is generated when the current is greater than the predetermined current. 2. If the application is specifically for the current detection circuit described in item 1, the first common potential of the towel is one of the positive or negative ends of a battery module. VIII 3. If the application is for the current system of the second job, the towel-charge-discharge switch is lightly connected to the first common potential and generates the current detection signal. 4. The current detecting circuit of claim 1, wherein the voltage dividing unit comprises one of a first impedance and a second impedance in series. 5· ΐΓΐSpecial, the current detecting circuit described in item 1 wherein the voltage dividing unit is further connected to the reference dragon to generate the voltage dividing signal according to the reference dragon. 6. The current detecting circuit of claim 2, wherein the voltage dividing unit receives the reference voltage 'to generate the minute according to the first common potential and the second common potential - and the reference voltage Pressure signal. 7·—A battery overcurrent protection controller, comprising: a first pin coupled to one end of a current detecting circuit; a first pin coupled to a positive terminal of a battery module; a second pin coupled Connected to the negative terminal of the battery module; and the current detecting circuit, according to the flow of the circuit to the current side circuit, the second current _峨, to check whether the battery module exceeds - the predetermined current', wherein the current detecting circuit comprises: The top unit is used to produce the second pin and the third pin, and the tenth tote, 14 Γ 201221984 one voltage unit is coupled to the reference voltage at one end to generate a reference according to the reference The voltage dividing signal; and the comparing unit receives the voltage dividing signal and the current detecting signal for generating an overcurrent protection signal when the current exceeds the predetermined current. 8. The battery overcurrent protection controller according to claim 7, wherein the flow circuit is a charge and discharge switch 'lightly connected to the positive end of the battery module or the negative two 9 U clear patent range item 8 The battery overcurrent protection controller further includes a unit that receives the charging and discharging switch when receiving the overcurrent protection signal. Pressing the second % item =, the battery, wherein the component resistance value is less than the ==== and a second impedance and the resistance of the first impedance