Secondary battery protection integrated circuit and battery device

Abstract

Circuit characteristics such as determination voltage can be easily changed. A secondary battery protection integrated circuit includes: a plurality of terminals including a power supply terminal, a ground terminal, a selection terminal, and a control terminal; a selection circuit that changes a first determination voltage in accordance with a resistance value of a first resistive element connected to the outside of the selection terminal; and a control circuit that outputs a signal for controlling charging or discharging of the secondary battery from the control terminal on the basis of a result of comparing a power supply voltage between the power supply terminal and the ground terminal with the first determination voltage.

Description

Technical Field

[0001] The present disclosure relates to a secondary battery protection integrated circuit and a battery device. Background Art

[0002] Conventionally, a battery protection integrated circuit is known, which includes: a memory unit that stores characteristic setting data for setting the circuit characteristics of the battery protection integrated circuit; and a setting circuit that sets the circuit characteristics of the battery protection integrated circuit to circuit characteristics corresponding to the content of the characteristic setting data read from the memory unit. If the characteristic setting data written to the memory unit changes, the circuit characteristics of the battery protection integrated circuit change, so that a plurality of different circuit characteristics can be handled by a common circuit structure.

[0003] Prior art literature

[0004] Patent Document 1: Japanese Patent No. 6520658 Summary of the invention

[0005] Problems to be solved by the invention

[0006] However, in the case of a method of writing characteristic setting data for setting circuit characteristics such as a determination voltage into a memory, a device and a technique for reliably writing data into the memory are required. Therefore, it is sometimes difficult to cope with data writing into the memory.

[0007] The present disclosure provides a secondary battery protection integrated circuit and a battery device that can easily change circuit characteristics such as a determination voltage.

[0008] Means for solving problems

[0009] A secondary battery protection integrated circuit of a first aspect has:

[0010] A plurality of terminals, including: a power terminal, a ground terminal, a selection terminal and a control terminal;

[0011] a selection circuit that changes a first determination voltage according to a resistance value of a first resistance element externally connected to the selection terminal; and

[0012] A control circuit outputs a signal for controlling charging or discharging of the secondary battery from the control terminal based on a result of comparing a power supply voltage between the power supply terminal and the ground terminal with the first determination voltage.

[0013] A secondary battery protection integrated circuit according to a second aspect has:

[0014] A plurality of terminals, including: a power terminal, a ground terminal, a selection terminal, a monitoring terminal and a control terminal;

[0015] a selection circuit that changes a second determination voltage according to a resistance value of a second resistance element externally connected to the selection terminal; and

[0016] A control circuit outputs a signal for controlling charging or discharging of the secondary battery from the control terminal based on a result of comparing a first potential difference between the monitoring terminal and a power supply terminal or a second potential difference between the monitoring terminal and a ground terminal with the second determination voltage.

[0017] A secondary battery protection integrated circuit according to a third aspect has:

[0018] A plurality of terminals, including: a power terminal, a ground terminal, a first selection terminal, a second selection terminal, a monitoring terminal, and a control terminal;

[0019] a selection circuit that changes a first determination voltage according to a resistance value of a first resistance element externally connected to the first selection terminal, and changes a second determination voltage according to a resistance value of a second resistance element externally connected to the second selection terminal; and

[0020] A control circuit that outputs a signal for controlling the charging or discharging of the secondary battery from the control terminal based on a result of comparing the power supply voltage between the power supply terminal and the ground terminal with the first judgment voltage, and outputs a signal for controlling the charging or discharging of the secondary battery from the control terminal based on a result of comparing a first potential difference between the monitoring terminal and the power supply terminal or a second potential difference between the monitoring terminal and the ground terminal with the second judgment voltage.

[0021] A secondary battery protection integrated circuit according to a fourth aspect has:

[0022] A plurality of terminals, including: a power terminal, a ground terminal, a selection terminal, a monitoring terminal and a control terminal;

[0023] a selection circuit that changes the first determination voltage and the second determination voltage according to a resistance value of a first resistance element externally connected to the selection terminal; and

[0024] A control circuit that outputs a signal for controlling the charging or discharging of the secondary battery from the control terminal based on a result of comparing the power supply voltage between the power supply terminal and the ground terminal with the first judgment voltage, and outputs a signal for controlling the charging or discharging of the secondary battery from the control terminal based on a result of comparing a first potential difference between the monitoring terminal and the power supply terminal or a second potential difference between the monitoring terminal and the ground terminal with the second judgment voltage.

[0025] Effects of the Invention

[0026] According to the present disclosure, circuit characteristics such as a determination voltage can be easily changed. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a circuit block diagram showing an example of a system including the secondary battery protection integrated circuit according to the first embodiment.

[0028] Figure 2 This is a circuit block diagram for explaining a configuration example of a first selector in a first selection circuit.

[0029] Figure 3 This is a table for explaining an operation example of the first selector.

[0030] Figure 4 This is a circuit block diagram for explaining a configuration example of a second selector in the second selection circuit.

[0031] Figure 5 This is a table for explaining an operation example of the second selector.

[0032] Figure 6 1 is a diagram showing a configuration of a first example of a first selection circuit.

[0033] Figure 7 1 is a diagram showing a configuration of a first example of a second selection circuit.

[0034] Figure 8 2 is a diagram showing a configuration of a second example of the first selection circuit.

[0035] Fig. 9 is a diagram showing the structure of a third example of the first selection circuit.

[0036] Fig.10 : is a table showing an example of the adjustment result of the overcharge detection voltage Vdet1 in the third example of the first selection circuit.

[0037] Fig.11 This is a circuit block diagram showing an example of a system including the secondary battery protection integrated circuit according to the second embodiment.

[0038] Fig.12 This is a circuit block diagram for explaining a configuration example of a selector in a selection circuit.

[0039] Fig.13 This is a table for explaining an operation example of the selector.

[0040] Fig.14 This is a circuit block diagram showing an example of a system including the secondary battery protection integrated circuit according to the third embodiment.

[0041] Fig.15This is a circuit block diagram showing an example of a system including a secondary battery protection integrated circuit according to a modification of the third embodiment. DETAILED DESCRIPTION

[0042] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0043] Figure 1 This is a circuit block diagram showing an example of a system including the secondary battery protection integrated circuit according to the first embodiment. Figure 1 The system 501 shown has a battery device 401 and an electronic device 300 .

[0044] The electronic device 300 is a device connected to the battery device 401. The electronic device 300 may be a charger for charging the battery device 401, or a load that operates using the power supplied from the battery device 401. Specific examples of such a load include mobile phones, smart phones, tablet devices, headphones, etc. The electronic device 300 is not limited to these devices.

[0045] The battery device 401 may be external to the electronic device 300 or may be internal to the electronic device 300. The battery device 401 is, for example, a battery pack that is detachably stored in the electronic device 300 and can supply power to the electronic device 300 while being connected to the electronic device 300. Figure 1 The plurality of terminals (a positive power supply terminal (terminal P+) and a negative power supply terminal (terminal P-)) shown are connected to each other. For example, when charging the secondary battery 210, the terminal P+ and the terminal P- are electrically connected to the charger (electronic device 300).

[0046] The battery device 401 includes a secondary battery 210 and a battery protection device 601 .

[0047] The secondary battery 210 is an example of a battery that can be charged and discharged. The secondary battery 210 supplies power to the electronic device 300 connected to the terminal P+ and the terminal P-. The secondary battery 210 can be charged by a charger connected to the terminal P+ and the terminal P-. As specific examples of the secondary battery 210, lithium ion batteries, lithium polymer batteries, etc. can be cited. The secondary battery 210 has a positive electrode 211 and a negative electrode 212.

[0048] The battery protection device 601 is an example of a secondary battery protection device that operates with the secondary battery 210 as a power source. The battery protection device 601 protects the secondary battery 210 from overcharging and the like by controlling the charging of the secondary battery 210, and protects the secondary battery 210 from overdischarging and the like by controlling the discharging of the secondary battery 210. The battery protection device 601 includes, for example, a terminal P+, a terminal P-, a terminal B+, a terminal B-, resistors R1, R2, R21, R22, R23, a capacitor C21, a power line 201, a ground line 202, a switch circuit 203, and a protection IC (Integrated Circuit) 101.

[0049] The battery protection device 601 is a component having a substrate on which at least the protection IC 101 and the resistance elements R1 and R2 are mounted.

[0050] The terminal P+ is an example of a load positive terminal, and is connected to the power line of the electronic device 300. The terminal P- is an example of a load negative terminal, and is connected to the ground line of the electronic device 300. The terminal B+ is an example of a battery positive terminal, and is connected to the positive electrode 211 of the secondary battery 210. The terminal B- is an example of a battery negative terminal, and is connected to the negative electrode 212 of the secondary battery 210.

[0051] The terminal B+ and the terminal P+ are connected by a power line 201 which is a positive current path. The power line 201 is a power path connecting the terminal B+ and the terminal P+. The power line 201 functions as a charging path for the charging current of the secondary battery 210 to flow and a discharging path for the discharging current of the secondary battery 210 to flow.

[0052] The terminal B- and the terminal P- are connected by a grounding line 202 which is a negative current path. The grounding line 202 is a power supply path connecting the terminal B- and the terminal P-. The grounding line 202 functions as a charging path for the charging current of the secondary battery 210 to flow and a discharging path for the discharging current of the secondary battery 210 to flow.

[0053] The switch circuit 203 is provided on the ground line 202 between the terminal B- and the terminal P-. The switch circuit 203 includes, for example, a charge control transistor TR1 and a discharge control transistor TR2, and is a series circuit in which the charge control transistor TR1 and the discharge control transistor TR2 are connected in series. The charge control transistor TR1 is a semiconductor switch element that cuts off the charge path of the secondary battery 210. The discharge control transistor TR2 is a semiconductor switch element that cuts off the discharge path of the secondary battery 210.

[0054] exist Figure 1In the case of a charge control transistor TR1 cutting off the ground line 202 for the charging current of the secondary battery 210, the discharge control transistor TR2 cutting off the ground line 202 for the discharge current of the secondary battery 210. The charge control transistor TR1 and the discharge control transistor TR2 are switching elements for switching on or off the ground line 202, and are inserted in series to the ground line 202. The charge control transistor TR1 and the discharge control transistor TR2 are, for example, N-channel MOSFETs (Metal Oxide Semiconductor Field Effect Transistors).

[0055] The charge control transistor TR1 has a parasitic diode D1 between the drain and the source, which has a forward direction opposite to the direction of the charging current of the secondary battery 210. The charge control transistor TR1 is a switching element inserted in series with the ground line 202 so that the forward direction of the parasitic diode D1 coincides with the direction in which the discharge current of the secondary battery 210 flows.

[0056] The discharge control transistor TR2 has a parasitic diode D2 between the drain and the source, with the forward direction being opposite to the discharge current of the secondary battery 210. The discharge control transistor TR2 is a switching element inserted in series with the ground line 202 so that the forward direction of the parasitic diode D2 coincides with the direction in which the charging current of the secondary battery 210 flows.

[0057] The protection IC 101 is an example of a secondary battery protection integrated circuit and operates using the secondary battery 210 as a power source.

[0058] The protection IC 101 has the following function: it protects the secondary battery 210 from the influence of over-discharge, etc. by controlling the switch circuit 203. For example, when the detection circuit 222 detects abnormal charging (for example, over-charging, over-current in the charging direction (charging over-current), etc.), the protection IC 101 protects the secondary battery 210 from the influence of abnormal charging by turning off the charging control transistor TR1. On the other hand, when the detection circuit 222 detects abnormal discharge (for example, over-discharge, over-current in the discharging direction (discharging over-current), etc.), the protection IC 101 protects the secondary battery 210 from the influence of abnormal discharge by turning off the discharge control transistor TR2.

[0059] The protection IC 101 includes, for example, a charge control terminal (terminal COUT), a discharge control terminal (terminal DOUT), a detection terminal (terminal VM), a power supply terminal (terminal VDD), a ground terminal (terminal VSS), a current detection terminal (terminal CS), a first selection terminal (terminal SEL1), and a second selection terminal (terminal SEL2). These terminals are, for example, external connection terminals for connecting the internal circuit of the protection IC 101 to the outside of the protection IC 101.

[0060] Terminal COUT is connected to the gate (control electrode) of charge control transistor TR1 and outputs a signal to turn on or off charge control transistor TR1. Terminal DOUT is connected to the gate (control electrode) of discharge control transistor TR2 and outputs a signal to turn on or off discharge control transistor TR2.

[0061] Terminal VM is an example of a monitoring terminal for monitoring the potential of terminal P-, and is connected to terminal P-. Terminal VM is used, for example, to protect the control circuit 221 in IC101 to monitor whether the electronic device 300 or the charger is connected. Terminal VM is connected to ground line 202 via resistor R23 between switch circuit 203 and terminal P-. Terminal VM is electrically connected to ground line 202 on the side opposite to secondary battery 210 with respect to switch circuit 203.

[0062] The terminal VM, like the terminal CS described later, can also be used to detect a charge overcurrent or a discharge overcurrent flowing through the secondary battery 210 .

[0063] Terminal VDD is a power supply terminal of the protection IC 101, and is connected to the positive electrode 211 of the secondary battery 210 and the power supply line 201 via the resistor element R21. Terminal VSS is a ground terminal of the protection IC 101, and is connected to the negative electrode 212 of the secondary battery 210. Capacitor C21 is connected between terminal VDD and terminal VSS. Terminal VSS is connected to the ground line 202 between the switch circuit 203 and the negative electrode 212. In this example, terminal VSS is connected to the ground line 202 between the resistor element R22 and the negative electrode 212.

[0064] Terminal CS is an example of a monitoring terminal for monitoring the charging current or discharging current flowing in the secondary battery 210, and is connected to the ground line 202 between the resistor element R22 and the switch circuit 203 (the source of the discharge control transistor TR2). The resistor element R22 is inserted in series into the ground line 202. One end of the resistor element R22 is connected to the terminal VSS, and the other end is connected to the terminal CS. The detection circuit 222 in the protection IC101 can detect the charging overcurrent or the discharging overcurrent flowing in the secondary battery 210 by detecting the potential difference between the terminal VSS and the terminal CS. The resistor element R22 functions as a sensing resistor for detecting the current flowing in the secondary battery 210.

[0065] The terminal SEL1 is a terminal for selecting the specification of the first determination voltage (in this example, the overcharge detection voltage Vdet1 and the overdischarge detection voltage Vdet2), and is externally connected to the resistor element R1. The resistor element R1 is an example of a first resistor element provided outside the protection IC 101. The terminal SEL1 is connected to the ground line 202 between the switch circuit 203 and the cathode 212 via the resistor element R1. In this example, the terminal SEL1 is connected to the ground line 202 between the resistor element R22 and the cathode 212.

[0066] The terminal SEL2 is a terminal for selecting the specification of the second determination voltage (discharge overcurrent detection voltage Vdet3 and charge overcurrent detection voltage Vdet4 in this example), and is externally connected to the resistor element R2. The resistor element R2 is an example of a second resistor element provided outside the protection IC 101. The terminal SEL2 is connected to the ground line 202 between the switch circuit 203 and the cathode 212 via the resistor element R2. In this example, the terminal SEL2 is connected to the ground line 202 between the resistor element R22 and the cathode 212.

[0067] The protection IC 101 includes a detection circuit 222 , a control circuit 221 , a first selection circuit 231 , and a second selection circuit 232 .

[0068] The detection circuit 222 detects overcharge of the secondary battery 210 by monitoring the power supply voltage Vdd between the terminal VDD and the terminal VSS. The detection circuit 222 compares the power supply voltage Vdd with the overcharge detection voltage Vdet1, and generates an overcharge detection signal indicating that overcharge of the secondary battery 210 is detected when the power supply voltage Vdd is higher than the overcharge detection voltage Vdet1.

[0069] The detection circuit 222 detects the overcharge current of the secondary battery 210 by monitoring the potential difference ΔV2 between the terminal VSS and the terminal CS (or the terminal VM). The detection circuit 222 compares the potential difference ΔV2 with the overcharge current detection voltage Vdet4, and generates a charge overcurrent detection signal indicating that the overcharge current of the secondary battery 210 has been detected when the potential difference ΔV2 is lower than the overcharge current detection voltage Vdet4 with respect to the terminal VSS as a reference. In other words, when the voltage of the terminal CS (or the terminal VM) is lower than the overcharge current detection voltage Vdet4 with respect to the terminal VSS as a reference, the detection circuit 222 generates the overcharge current detection signal.

[0070] The control circuit 221 has a charging control circuit 221a that controls the charging of the secondary battery 210. When the overcharge of the secondary battery 210 continues for a predetermined detection delay time d1 and is detected by the detection circuit 222, the charging control circuit 221a outputs a signal (for example, a low-level gate control signal) from the terminal COUT to switch the charging control transistor TR1 from on to off. When the overcurrent of the charging of the secondary battery 210 continues for a predetermined detection delay time d4 and is detected by the detection circuit 222, the charging control circuit 221a outputs a signal (for example, a low-level gate control signal) from the terminal COUT to switch the charging control transistor TR1 from on to off.

[0071] The control circuit 221 turns off the charge control transistor TR1 to prohibit the current from flowing through the ground line 202 in the direction of charging the secondary battery 210. Thus, charging of the secondary battery 210 is stopped, and the protection IC 101 can protect the secondary battery 210 from overcharging or charging overcurrent.

[0072] The detection circuit 222 detects overdischarge of the secondary battery 210 by monitoring the power supply voltage Vdd between the terminal VDD and the terminal VSS. The detection circuit 222 compares the power supply voltage Vdd with the overdischarge detection voltage Vdet2, and generates an overdischarge detection signal indicating that overdischarge of the secondary battery 210 is detected when the power supply voltage Vdd is lower than the overdischarge detection voltage Vdet2.

[0073] The detection circuit 222 detects the discharge overcurrent of the secondary battery 210 by monitoring the potential difference ΔV2 between the terminal VSS and the terminal CS (or the terminal VM). The detection circuit 222 compares the potential difference ΔV2 with the discharge overcurrent detection voltage Vdet3, and generates a discharge overcurrent detection signal indicating that the discharge overcurrent of the secondary battery 210 has been detected when the potential difference ΔV2 is higher than the discharge overcurrent detection voltage Vdet3 with respect to the terminal VSS as a reference. In other words, when the voltage of the terminal CS (or the terminal VM) is higher than the discharge overcurrent detection voltage Vdet3 with respect to the terminal VSS as a reference, the detection circuit 222 generates the discharge overcurrent detection signal.

[0074] The control circuit 221 has a discharge control circuit 221b that controls the discharge of the secondary battery 210. When the overdischarge of the secondary battery 210 continues for a predetermined detection delay time d2 and is detected by the detection circuit 222, the discharge control circuit 221b outputs a signal (for example, a low-level gate control signal) from the terminal DOUT to switch the discharge control transistor TR2 from on to off. When the discharge overcurrent of the secondary battery 210 continues for a predetermined detection delay time d3 and is detected by the detection circuit 222, the discharge control circuit 221b outputs a signal (for example, a low-level gate control signal) from the terminal DOUT to switch the discharge control transistor TR2 from on to off.

[0075] The control circuit 221 turns off the discharge control transistor TR2 to prohibit the current in the direction of discharging the secondary battery 210 from flowing through the ground line 202. Thus, the discharge of the secondary battery 210 is stopped, and the protection IC 101 can protect the secondary battery 210 from overdischarge or discharge overcurrent.

[0076] The first selection circuit 231 changes the overcharge detection voltage Vdet1 according to the resistance value of the resistor R1 externally connected to the terminal SEL1. Thus, if the resistance value of the resistor R1 externally provided to the protection IC 101 is changed, the overcharge detection voltage Vdet1 can be easily changed. By using the resistor R1 externally provided to the protection IC 101, the specification of the overcharge detection voltage Vdet1 can be easily changed when the protection IC 101 is mounted on a substrate.

[0077] The first selection circuit 231 changes the overcharge detection voltage Vdet1 to a voltage value corresponding to the resistance value of the resistor R1 externally connected to the terminal SEL1, for example, according to a correspondence relationship preset in the first selection circuit 231. In this case, if the resistance value of the resistor R1 externally connected to the terminal SEL1 is changed to a specified resistance value, the protection IC 101 can be used in common in products (for example, the battery protection device 601 or the battery device 401, etc.) having different required specifications for the overcharge detection voltage Vdet1. As a result, for example, inventory management can be simplified and production man-hours can be reduced.

[0078] The first selection circuit 231 may include a first potential changing circuit that changes the potential (first selection potential VSEL1) of the terminal SEL1 according to the resistance value of the resistance element R1 externally connected to the terminal SEL1, and changes the overcharge detection voltage Vdet1 to a voltage value corresponding to the first selection potential VSEL1. Thus, if the resistance value of the resistance element R1 externally connected to the protection IC 101 is changed, the first selection potential VSEL1 changes, and thus the overcharge detection voltage Vdet1 can be easily changed. The first selection circuit 231 changes the overcharge detection voltage Vdet1 to a voltage value corresponding to the first selection potential VSEL1, for example, according to a correspondence relationship pre-set in the first selection circuit 231.

[0079] The first selection circuit 231 changes the overdischarge detection voltage Vdet2 according to the resistance value of the resistor R1 externally connected to the terminal SEL1. When the first selection circuit 231 changes the overdischarge detection voltage Vdet2, it is the same as when the first selection circuit 231 changes the overcharge detection voltage Vdet1, so the above description is omitted by citing the above description.

[0080] The second selection circuit 232 changes the charge overcurrent detection voltage Vdet4 according to the resistance value of the resistor R2 externally connected to the terminal SEL2. Thus, if the resistance value of the resistor R2 externally provided to the protection IC 101 is changed, the charge overcurrent detection voltage Vdet4 can be changed. By using the resistor R2 externally provided to the protection IC 101, the specification of the charge overcurrent detection voltage Vdet4 can be easily changed even when the protection IC 101 is mounted on a substrate.

[0081] The second selection circuit 232 changes the charge overcurrent detection voltage Vdet4 to a voltage value corresponding to the resistance value of the resistance element R2 externally connected to the terminal SEL2, for example, according to a correspondence relationship preset in the second selection circuit 232. In this case, if the resistance value of the resistance element R2 externally connected to the terminal SEL2 is changed to a specified resistance value, the protection IC 101 can be used in common in products (for example, the battery protection device 601 or the battery device 401, etc.) having different required specifications for the charge overcurrent detection voltage Vdet4. This can, for example, simplify inventory management and reduce production man-hours.

[0082] The second selection circuit 232 may include a second potential changing circuit that changes the potential (second selection potential VSEL2) of the terminal SEL2 according to the resistance value of the resistance element R2 externally connected to the terminal SEL2, and changes the charge overcurrent detection voltage Vdet4 to a voltage value corresponding to the second selection potential VSEL2. Thus, if the resistance value of the resistance element R2 externally connected to the protection IC 101 is changed, the second selection potential VSEL2 changes, and thus the charge overcurrent detection voltage Vdet4 can be easily changed. The second selection circuit 232 changes the charge overcurrent detection voltage Vdet4 to a voltage value corresponding to the second selection potential VSEL2, for example, according to a correspondence relationship pre-set in the second selection circuit 232.

[0083] The second selection circuit 232 changes the discharge overcurrent detection voltage Vdet3 according to the resistance value of the resistance element R2 externally connected to the terminal SEL2. When the second selection circuit 232 changes the discharge overcurrent detection voltage Vdet3, it is the same as when the second selection circuit 232 changes the charge overcurrent detection voltage Vdet4, so the description thereof is omitted by citing the above description.

[0084] Figure 2 2 is a diagram for explaining a configuration example of a first selector in a first selection circuit. The first selection circuit 231 includes a first selector 241 as a component. The first selector 241 is a circuit that selects a selection signal corresponding to the resistance value of the resistor R1 externally connected to the terminal SEL1 from a plurality of different selection signals S11, S12, and S13 when the first read signal ΦREAD1 is in an active state. The plurality of different selection signals S11, S12, and S13 are selection signal candidates pre-set in the first decoder 271 in the first selector 241.

[0085] The first selector 241 includes a first potential changing circuit 251, which changes the potential (first selection potential VSEL1) of the terminal SEL1 through the reference resistor Rx and the switch LD2 according to the resistance value of the resistor element R1 externally connected to the terminal SEL1. The reference resistor Rx is inserted in series into the current path between the first selection terminal SEL1 and the terminal VDD. When the switch LD2 is turned on by the first read signal ΦREAD1, the first selection terminal SEL1 is pulled up and connected to the terminal VDD through the reference resistor Rx, so that the first selection potential VSEL1 changes according to the resistance value of the resistor element R1.

[0086] The first selector 241 includes a first encoder 261. The first encoder 261 is a circuit that encodes the first selection potential VSEL1 and outputs a code (LV11, LV12, LV13, LV14) corresponding to the resistance value of the resistor element R1. The first encoder 261 has: a plurality of series resistors inserted in series between the terminal VDD and the terminal VSS; and a plurality of comparators that compare the first selection potential VSEL1 with a plurality of potentials V1, V2, V3, and V4. When the switch LD1 is turned on by the first read signal ΦREAD1, a plurality of different potentials V1, V2, V3, and V4 are generated by voltage division based on these plurality of series resistors.

[0087] The first selector 241 includes a first decoder 271. The first decoder 271 is a circuit that converts the code (LV11, LV12, LV13, LV14) into a selection signal and an error signal ERROR. The first decoder 271 outputs selection signals S11, S12, S13 and an error signal ERROR as a result of selecting the code (LV11, LV12, LV13, LV14). The selection signals S11, S12, S13 and the error signal ERROR output from the first decoder 271 are held in the latch circuit LT.

[0088] Figure 3 TABLE 241 is a table for explaining an operation example of the first selector. The first selector 241 becomes an operable state when the first read signal ΦREAD1 is in an active state (in this example, in a high level "H"). In the operable state, the first selector 241 outputs the result of selecting the first selection potential VSEL1 corresponding to the resistance value of the resistor element R1 externally connected to the terminal SEL1 from the first decoder 271. In the first selector 241, when the first read signal ΦREAD1 changes from an active state to an inactive state (in this example, in a low level "L"), the selection result is held in the latch circuit LT.

[0089] For example, when the first selection potential VSEL1 is higher than the potential of the terminal VSS and lower than the potential V1, or higher than the potential V4 and lower than the potential of the terminal VDD, the first selector 241 selects the error signal ERROR, and the error signal ERROR is held in the latch circuit LT. When the first selection potential VSEL1 is higher than the potential V1 and lower than the potential V2, the first selector 241 holds the selected selection signal S11 in the latch circuit LT. In this way, the first selector 241 selects the error signal ERROR in accordance with the first selection potential VSEL1. Figure 3 The selected signal is selected according to the correspondence relationship shown, and the selected signal is held in the latch circuit LT.

[0090] When the first read signal ΦREAD1 is in an inactive state, the current supplied to the first selector 241 is cut off. As a result, the current consumption of the first selector 241 is reduced, and thus the power consumption of the protection IC 101 is suppressed. Figure 2 In the case of , when the first read signal ΦREAD1 is in an inactive state, the switches LD1 and LD2 are turned off, so the current flowing through the reference resistor Rx and the plurality of series resistors is reduced.

[0091] For example, the control circuit 221 sets the first read signal ΦREAD1 to an active state when overdischarge of the secondary battery 210 is detected, and sets the first read signal ΦREAD1 to an inactive state when overdischarge of the secondary battery 210 is not detected. Thus, the first selector 241 operates only during a specific period in which overdischarge is detected, and stops during other periods, thereby improving the power consumption suppression effect of the protection IC 101. In addition, the first read signal ΦREAD1 can be set to a pulse signal having an active state shorter than the time of detecting overdischarge when overdischarge is detected. As a result, the power consumption suppression effect of the protection IC 101 can be effectively improved.

[0092] When the resistance value of the resistor element R1 is higher than the first specified value (in this example, the first selection potential VSEL1 is higher than the potential V4 and is lower than the potential of the terminal VDD), the first selection circuit 231 outputs the error signal ERROR. Alternatively, when the resistance value of the resistor element R1 is lower than the second specified value (in this example, the first selection potential VSEL1 is higher than the potential of the terminal VSS and is lower than the potential V1), the first selection circuit 231 outputs the error signal ERROR. In this way, an abnormality caused by the disconnection of the resistor element R1 external to the protection IC 101 or the short circuit of the terminal SEL1 can be detected.

[0093] For example, when the error signal ERROR is output, the control circuit 221 outputs a signal from the terminal COUT to stop charging the secondary battery 210, or outputs a signal from the terminal DOUT to stop discharging the secondary battery 210, or both. Thus, safety against abnormality of the resistor R1 can be ensured.

[0094] Figure 4 2 is a diagram for explaining a configuration example of a second selector in a second selection circuit. The second selection circuit 232 includes a second selector 242 as a component. The second selector 242 is a circuit that selects a selection signal corresponding to the resistance value of the resistor R2 externally connected to the terminal SEL2 from a plurality of different selection signals S21, S22, and S23 when the second read signal ΦREAD2 is in an active state. The plurality of different selection signals S21, S22, and S23 are selection signal candidates pre-set in the second decoder 272 in the second selector 242. The second read signal ΦREAD2 may be the same signal as the first read signal ΦREAD1, or may be a different signal.

[0095] The second selector 242 includes a second potential changing circuit 252, which changes the potential of the terminal SEL2 (second selection potential VSEL2) through the reference resistor Rx and the switch LD2 according to the resistance value of the resistor element R2 externally connected to the terminal SEL2. The reference resistor Rx is inserted in series into the current path between the second selection terminal SEL2 and the terminal VDD. When the switch LD2 is turned on by the second read signal ΦREAD2, the second selection terminal SEL2 is pulled up and connected to the terminal VDD through the reference resistor Rx, so that the second selection potential VSEL2 changes according to the resistance value of the resistor element R2.

[0096] The second selector 242 includes a second encoder 262. The second encoder 262 is a circuit that encodes the second selection potential VSEL2 and outputs a code (LV21, LV22, LV23, LV24) corresponding to the resistance value of the resistor element R2. The second encoder 262 has a plurality of series resistors inserted in series between the terminal VDD and the terminal VSS and a plurality of comparators that compare the second selection potential VSEL2 with a plurality of potentials V1, V2, V3, and V4. When the switch LD1 is turned on by the second read signal ΦREAD2, a plurality of different potentials V1, V2, V3, and V4 are generated by voltage division based on these plurality of series resistors.

[0097] The second selector 242 includes a second decoder 272. The second decoder 272 is a circuit that converts the code (LV21, LV22, LV23, LV24) into a selection signal and an error signal ERROR. The second decoder 272 outputs the selection signals S21, S22, S23 and the error signal ERROR as a result of decoding the code (LV21, LV22, LV23, LV24). The selection signals S21, S22, S23 and the error signal ERROR output from the second decoder 272 are held in the latch circuit LT.

[0098] Figure 5 : is a table for explaining an operation example of the second selector. The second selector 242 becomes an operable state when the second read signal ΦREAD2 is in an active state (in this example, it is a high level "H"). In the operable state, the second selector 242 outputs the result of selecting the second selection potential VSEL2 corresponding to the resistance value of the resistor element R2 externally connected to the terminal SEL2 from the second decoder 272. In the second selector 242, when the second read signal ΦREAD2 changes from an active state to an inactive state (in this example, it is a low level "L"), the selection result is held in the latch circuit LT.

[0099] For example, when the second selection potential VSEL2 is higher than the potential of the terminal VSS and lower than the potential V1, or higher than the potential V4 and lower than the potential of the terminal VDD, the second selector 242 selects the error signal ERROR, and the error signal ERROR is held in the latch circuit LT. When the second selection potential VSEL2 is higher than the potential V1 and lower than the potential V2, the second selector 242 holds the selected selection signal S21 in the latch circuit LT. In this way, the second selector 242 selects the error signal ERROR in accordance with the voltage drop. Figure 5 The selected signal is selected according to the correspondence relationship shown, and the selected signal is held in the latch circuit LT.

[0100] When the second read signal ΦREAD2 is in an inactive state, the current supplied to the second selector 242 is cut off. As a result, the current consumption of the second selector 242 is reduced, and thus the power consumption of the protection IC 101 is suppressed. Figure 4 In the case of , when the second read signal ΦREAD2 is in an inactive state, the switches LD1 and LD2 are turned off, so the current flowing through the reference resistor Rx and the plurality of series resistors is reduced.

[0101] For example, the control circuit 221 sets the second read signal ΦREAD2 to an active state when overdischarge of the secondary battery 210 is detected, and sets the second read signal ΦREAD2 to an inactive state when overdischarge of the secondary battery 210 is not detected. Thus, the second selector 242 operates only during a specific period in which overdischarge is detected, and stops during other periods, thereby improving the power consumption suppression effect of the protection IC 101. In addition, the second read signal ΦREAD2 can be set to a pulse signal having an active state shorter than the time of detecting overdischarge when overdischarge is detected. As a result, the power consumption suppression effect of the protection IC 101 can be effectively improved.

[0102] When the resistance value of the resistor element R2 is higher than the first specified value (in this example, the second selection potential VSEL2 is higher than the potential V4 and is lower than the potential of the terminal VDD), the second selection circuit 232 outputs the error signal ERROR. Alternatively, when the resistance value of the resistor element R2 is lower than the second specified value (in this example, the second selection potential VSEL2 is higher than the potential of the terminal VSS and is lower than the potential V1), the second selection circuit 232 outputs the error signal ERROR. In this way, an abnormality caused by the disconnection of the resistor element R2 external to the protection IC 101 or the short circuit of the terminal SEL2 can be detected.

[0103] For example, when the error signal ERROR is output, the control circuit 221 outputs a signal from the terminal COUT to stop charging the secondary battery 210, or outputs a signal from the terminal DOUT to stop discharging the secondary battery 210, or both. Thus, safety against abnormality of the resistor R2 can be ensured.

[0104] Figure 6 2 is a diagram showing a first example of the first selection circuit. Since the first selection circuit 231 and the second selection circuit 232 have the same structure and function, the description of the first example of the first selection circuit 231 is cited and the description of the first example of the second selection circuit 232 is omitted. Figure 6 The first selection circuit 231A shown is a first example of the first selection circuit 231 .

[0105] When k is an integer equal to or greater than 2, the first selection circuit 231A adjusts the overcharge detection voltage Vdet1 to any one of k voltage values. Figure 6 Take the case where k is 3. The first selection circuit 231A includes a first selector 241 , a fine-tuning circuit 291 , and an adjustment circuit 281 .

[0106] The first selector 241 is a circuit that selects a selection signal corresponding to the resistance value of the resistor R1 externally connected to the terminal SEL1 from k (3 in this example) different selection signals S11, S12, and S13 when the first read signal ΦREAD1 is in an active state. The fine-tuning circuit 291 has a plurality of (=k×n) fine-tuning elements. n is an integer greater than 2, and in this example, k=3. The first selector 241 selects a plurality of fine-tuning elements corresponding to the resistance value of the resistor R1 (the first selection potential VSEL1 in this example) from a plurality of fine-tuning elements F11, F12, F13, F21, F22, F23, ..., Fn1, Fn2, and Fn3 in the fine-tuning circuit 291.

[0107] The trimming circuit 291 includes a plurality of (=3×n) trimming elements F11, F12, F13, F21, F22, F23, ..., Fn1, Fn2, Fn3, a plurality of (=3×n) switch elements N11, N12, N13, N21, N22, N23, ..., Nn1, Nn2, Nn3, and n resistors RD1, RD2, ..., RDn. The plurality of trimming elements F11, F12, F13, F21, F22, F23, ..., Fn1, Fn2, Fn3 are connected in series with the corresponding switch elements N11, N12, N13, N21, N22, N23, ..., Nn1, Nn2, Nn3, respectively. The trimming element is, for example, a fuse element that can be cut by laser irradiated from the outside of the protection IC 101. The fine-tuning circuit 291 may also be an OTP (One Time Programmable) memory.

[0108] The adjustment circuit 281 adjusts the overcharge detection voltage Vdet1 to a voltage value corresponding to the trimming state of each of the plurality of trimming elements selected by the first selector 241. The adjustment circuit 281 includes n latch circuits LT for holding the trimming states of each of the plurality of trimming elements, a resistor RH, a resistor RL (n trimming resistors R1 to Rn), and n switch elements M1 to Mn.

[0109] In the adjustment circuit 281, when the first read signal ΦREAD1 changes from an active state to an inactive state (low level "L" in this example), the fine adjustment states of the plurality of fine adjustment elements selected by the first selector 241 are held in the plurality of latch circuits LT. The plurality of latch circuits LT output signals indicating their held states.

[0110] The n switch elements M1 to Mn are connected in parallel to the corresponding trimming resistors R1 to Rn, respectively, and are turned on or off by the output of the corresponding latch circuit LT.

[0111] When the power supply voltage Vdd rises, the detection voltage VIN+ obtained by dividing the power supply voltage Vdd by the resistors RH and RL also rises. When the detection voltage VIN+ exceeds the reference voltage Vref, the output of the comparator 222a in the detection circuit 222 inverts. The power supply voltage Vdd at this inversion is set as the overcharge detection voltage Vdet1.

[0112] Figure 6 The example shows a case where a plurality of fine-tuning elements corresponding to one selection signal selected by the first selector 241 are selected from the plurality of selection signals S11, S12, and S13. The resistance value of the resistor RL is changed according to the fine-tuning state of each of the selected plurality of fine-tuning elements, thereby adjusting the overcharge detection voltage Vdet1 to any one of k types (three in this example) of voltage values.

[0113] When the selection signal S11 is selected by the first selector 241, the overcharge detection voltage Vdet1 is adjusted to, for example, 4.2 volts. When the selection signal S11 is selected, only the switch elements N11, N21, ..., Nn1 corresponding to the selection signal S11 are turned on, and thus the fine-tuning elements F11, F21, ..., Fn1 are selected (become effective). Each of the fine-tuning elements F11, F21, ..., Fn1 selected by the selection signal S11 is fine-tuned so that the overcharge detection voltage Vdet1 is 4.2 volts. The resistance value of the resistor RL is adjusted to a resistance value corresponding to the fine-tuning state of each of the fine-tuning elements F11, F21, ..., Fn1 by the adjustment circuit 281. As a result, the overcharge detection voltage Vdet1 is fine-tuned to 4.2 volts. If the resistance value of the resistor RL when the overcharge detection voltage Vdet1 is 4.2 V is denoted as RL1, the overcharge detection voltage Vdet1 is expressed by "Vdet1 = (RH + RL1) × Vref / RL1".

[0114] When the selection signal S12 is selected by the first selector 241, the overcharge detection voltage Vdet1 is adjusted to, for example, 4.3 volts. When the selection signal S12 is selected, only the switch elements N12, N22, ..., Nn2 corresponding to the selection signal S12 are turned on, and thus the fine-tuning elements F12, F22, ..., Fn2 are selected (become effective). Each of the fine-tuning elements F12, F22, ..., Fn2 selected by the selection signal S12 is fine-tuned so that the overcharge detection voltage Vdet1 is 4.3 volts. The resistance value of the resistor RL is adjusted to a resistance value corresponding to the fine-tuning state of each of the fine-tuning elements F12, F22, ..., Fn2 by the adjustment circuit 281. As a result, the overcharge detection voltage Vdet1 is fine-tuned to 4.3 volts. If the resistance value of the resistor RL when the overcharge detection voltage Vdet1 is 4.3 V is represented by RL2, the overcharge detection voltage Vdet1 is expressed by "Vdet1 = (RH + RL2) × Vref / RL2".

[0115] When the selection signal S13 is selected by the first selector 241, the overcharge detection voltage Vdet1 is adjusted to, for example, 4.4 volts. When the selection signal S13 is selected, only the switch elements N13, N23, ..., Nn3 corresponding to the selection signal S13 are turned on, so that the fine-tuning elements F13, F23, ..., Fn3 are selected (become effective). Each of the fine-tuning elements F13, F23, ..., Fn3 selected by the selection signal S13 is fine-tuned so that the overcharge detection voltage Vdet1 is 4.4 volts. The resistance value of the resistor RL is adjusted to a resistance value corresponding to the fine-tuning state of each of the fine-tuning elements F13, F23, ..., Fn3 by the adjustment circuit 281. As a result, the overcharge detection voltage Vdet1 is fine-tuned to 4.4 volts. If the resistance value of the resistor RL when the overcharge detection voltage Vdet1 is 4.4 V is denoted by RL3, the overcharge detection voltage Vdet1 is expressed by "Vdet1 = (RH + RL3) × Vref / RL3".

[0116] The first selection circuit 231A adjusts the overdischarge detection voltage Vdet2 in the same manner as the overcharge detection voltage Vdet1. The second selection circuit 232 adjusts the discharge overcurrent detection voltage Vdet3 or the charge overcurrent detection voltage Vdet4 in the same manner as the first selection circuit 231A adjusts the overcharge detection voltage Vdet1.

[0117] For example, by Figure 7 In the structure shown, the second selection circuit 232 adjusts the charge overcurrent detection voltage Vdet4. Figure 7 The second selection circuit 232A shown is an example of the second selection circuit 232 .

[0118] Figure 8 2 is a diagram showing a second example of the first selection circuit. The first selection circuit 231 and the second selection circuit 232 have the same structure and function, and therefore, the description of the second example of the first selection circuit 231 is cited and the description of the second example of the second selection circuit 232 is omitted. Figure 8 The first selection circuit 231B shown is a second example of the first selection circuit 231. The above description is used for the same structure as the first example of the first selection circuit 231. The first selection circuit 231B includes: a first selector 241, a fine adjustment circuit 291, and an adjustment circuit 282. The first selector 241 and the fine adjustment circuit 291 can be the same as the case of the first selection circuit 231A.

[0119] The adjustment circuit 282 adjusts the overcharge detection voltage Vdet1 to a voltage value corresponding to the fine-tuning state of each of the plurality of fine-tuning elements selected by the first selector 241. The adjustment circuit 282 includes: n latch circuits LT for holding the fine-tuning states of each of the plurality of fine-tuning elements, a resistor RH (resistor R0), a resistor RL (n fine-tuning resistors R1 to Rn), and n switch elements M1 to Mn. n is an integer greater than or equal to 2.

[0120] In the adjustment circuit 282, when the first read signal ΦREAD1 changes from an active state to an inactive state (low level "L" in this example), the fine adjustment states of the plurality of fine adjustment elements selected by the first selector 241 are held in the plurality of latch circuits LT. The plurality of latch circuits LT output signals indicating their held states.

[0121] One end of the n switch elements M1 to Mn is connected to one end of the corresponding trimming resistors R1 to Rn. The n switch elements M1 to Mn are turned on or off by the output of the corresponding latch circuit LT. The other ends of the n switch elements M1 to Mn are connected to each other and to the non-inverting input terminal of the comparator 222a.

[0122] The first selection circuit 231B finely adjusts the overcharge detection voltage Vdet1, similarly to the first selection circuit 231A described above. The first selection circuit 231A adjusts the resistance value of the resistor RL by short-circuiting the fine-tuning resistor, but the first selection circuit 231B adjusts the resistance value of the resistor RL by selecting a node between the fine-tuning resistors. Similar to the first selection circuit 231A, in the case of the first selection circuit 231B, the overcharge detection voltage Vdet1 is also expressed by "Vdet1 = (RH + RL) × Vref / RL".

[0123] The first selection circuit 231B adjusts the overdischarge detection voltage Vdet2 in the same manner as the overcharge detection voltage Vdet1. The second selection circuit 232 adjusts the discharge overcurrent detection voltage Vdet3 or the charge overcurrent detection voltage Vdet4 in the same manner as the first selection circuit 231B adjusts the overcharge detection voltage Vdet1.

[0124] Fig. 9 2 is a diagram showing a third example of the first selection circuit. The first selection circuit 231 and the second selection circuit 232 have the same structure and function, and therefore, the description of the third example of the first selection circuit 231 is cited and the description of the third example of the second selection circuit 232 is omitted. Fig. 9 The first selection circuit 231C shown is a third example of the first selection circuit 231. For the same configuration as that of the first example or the second example of the first selection circuit 231, the above description is used.

[0125] When k is an integer equal to or greater than 2, the first selection circuit 231C adjusts the overcharge detection voltage Vdet1 to any one of k voltage values. Figure 6 The case where k is 3 is taken as an example. The first selection circuit 231C includes: a first selector 241, a fine-tuning circuit 273, and an adjustment circuit 283. The first selector 241 may be the same as that of the first selection circuit 231A.

[0126] The first selector 241 is a circuit that selects a selection signal corresponding to the resistance value of the resistor R1 externally connected to the terminal SEL1 from k (three in this example) different selection signals S11, S12, and S13 when the first read signal ΦREAD1 is in an active state. The first selector 241 selects a potential corresponding to the selected selection signal from k (three in this example) different potentials V42, V43, and V44, and sets the selected potential as the potential VN on the reference potential side of the comparator 222a. The first selection circuit 231C sets the potential VN according to the selected selection signal, thereby adjusting the overcharge detection voltage Vdet1 to one of the k (three in this example) voltage values.

[0127] The fine-tuning circuit 273 includes k (three in this example) fine-tuning elements F1, F2, F3, k (three in this example) resistors Rd1, Rd2, Rd3, and a fine-tuning control circuit 273a. The plurality of resistors Rd1, Rd2, Rd3 are connected in series with the corresponding fine-tuning elements F1, F2, F3, respectively. The fine-tuning control circuit 273a decodes the fine-tuning states of the k (three in this example) fine-tuning elements F1, F2, F3 into 2 k A circuit that can transmit 8 (in this case 8) signals.

[0128] The adjustment circuit 283 adjusts the overcharge detection voltage Vdet1 to a voltage value corresponding to a selection signal selected by the first selector 241. The adjustment circuit 283 includes a resistor RVH (fixed resistors RV1, RV2, RV3), a resistor RVL (fixed resistors RV4, RV5), a resistor RX (m trimming resistors R1 to Rm), 2 k (8 in this example) switching elements M1 to M8, and a regulator 283a. m is an integer greater than or equal to 2.

[0129] In the first selection circuit 231C, the resistor RX is first adjusted so that the output voltage VREG of the regulator 28 is a predetermined target value (e.g., 1.80 volts). The resistor RX is adjusted by the switch elements M1 to M8 that are turned on or off according to the respective trimming states of the trimming elements F1, F2, and F3. Thus, the values ​​of the potentials V42, V43, and V44 are determined.

[0130] The first selector 241 selects a potential corresponding to a selected selection signal from a plurality of different potentials V42, V43, and V44, and sets the selected potential as the potential VN (the potential of the inverting input terminal) on the reference potential side of the comparator 222a. The potential VP (the potential of the non-inverting input terminal) on the comparison side of the comparator 222a is a fixed value (=Vdd×RVL / (RVH+RVL)). As a result, according to the selected selection signal, Fig.10 The overcharge detection voltage Vdet1 is adjusted as shown.

[0131] The first selection circuit 231C adjusts the overdischarge detection voltage Vdet2 in the same manner as the overcharge detection voltage Vdet1. The second selection circuit 232 adjusts the discharge overcurrent detection voltage Vdet3 or the charge overcurrent detection voltage Vdet4 in the same manner as the first selection circuit 231C adjusts the overcharge detection voltage Vdet1.

[0132] Fig.11 The circuit block diagram of an example of a system including a secondary battery protection integrated circuit of the second embodiment. In the second embodiment, the description of the structure, function and effect similar to the first embodiment is omitted by citing the above description. The difference between the second embodiment and the first embodiment is that the selection terminal, the external resistance element and the selection circuit are integrated into one.

[0133] Fig.11The system 502 shown has a battery device 402 and an electronic device 300. The battery device 402 has a secondary battery 210 and a battery protection device 602. The battery protection device 602 is a component having a substrate on which at least a protection IC 102 and a resistor R0 are mounted. The protection IC 102 has, for example, a charge control terminal (terminal COUT), a discharge control terminal (terminal DOUT), a detection terminal (terminal VM), a power supply terminal (terminal VDD), a ground terminal (terminal VSS), a current detection terminal (terminal CS), a selection terminal (terminal SEL0), and a selection circuit 230.

[0134] The terminal SEL0 is a terminal for selecting the specifications of the first determination voltage (in this example, the overcharge detection voltage Vdet1 or the overdischarge detection voltage Vdet2) and the second determination voltage (in this example, the discharge overcurrent detection voltage Vdet3 or the charge overcurrent detection voltage Vdet4), and is externally connected to the resistor element R0. The resistor element R0 is an example of a first resistor element provided outside the protection IC 102.

[0135] The selection circuit 230 changes the first determination voltage and the second determination voltage according to the resistance value of the resistance element R0 externally connected to the terminal SEL0. For example, the first determination voltage may be set to the overcharge detection voltage Vdet1, and the second determination voltage may be set to the charge overcurrent detection voltage Vdet4, or the first determination voltage may be set to the overdischarge detection voltage Vdet2, and the second determination voltage may be set to the discharge overcurrent detection voltage Vdet3. In the following description of the second embodiment, the case where the first determination voltage is the overcharge detection voltage Vdet1 and the second determination voltage is the charge overcurrent detection voltage Vdet4 is used as a representative description.

[0136] The selection circuit 230 changes the overcharge detection voltage Vdet1 and the charge overcurrent detection voltage Vdet4 according to the resistance value of the resistance element R0 externally connected to the terminal SEL0. Thus, if the resistance value of the resistance element R1 external to the protection IC 102 is changed, the overcharge detection voltage Vdet1 and the charge overcurrent detection voltage Vdet4 can be easily changed. By using the resistance element R0 external to the protection IC 102, the specifications of the overcharge detection voltage Vdet1 and the charge overcurrent detection voltage Vdet4 can be easily changed when the protection IC 102 is mounted on the substrate.

[0137] The selection circuit 230 changes the overcharge detection voltage Vdet1 and the charge overcurrent detection voltage Vdet4 to voltage values ​​corresponding to the resistance value of the resistor R0 externally connected to the terminal SEL0, for example, according to a correspondence relationship preset in the selection circuit 230. In this case, if the resistance value of the resistor R0 externally connected to the terminal SEL0 is changed to a specified resistance value, the protection IC 102 can be used in common in products (for example, the battery protection device 602 or the battery device 402, etc.) having different required specifications for the overcharge detection voltage Vdet1 and the charge overcurrent detection voltage Vdet4. This can, for example, simplify inventory management and reduce production man-hours.

[0138] The selection circuit 230 may include a potential changing circuit that changes the potential of the terminal SEL0 (selection potential VSEL0) according to the resistance value of the resistor R0 externally connected to the terminal SEL0, and changes the overcharge detection voltage Vdet1 and the charge overcurrent detection voltage Vdet4 to voltage values ​​corresponding to the selection potential VSEL0. Thus, if the resistance value of the resistor R0 externally connected to the protection IC 102 is changed, the selection potential VSEL0 changes, and thus the overcharge detection voltage Vdet1 and the charge overcurrent detection voltage Vdet4 can be easily changed. The selection circuit 230 changes the overcharge detection voltage Vdet1 and the charge overcurrent detection voltage Vdet4 to voltage values ​​corresponding to the selection potential VSEL0, for example, according to a correspondence relationship pre-set in the selection circuit 230.

[0139] Fig.12 2 is a diagram for explaining a configuration example of a selector in a selection circuit. The selection circuit 230 includes a selector 240 as a component. The selector 240 is a circuit that selects a selection signal corresponding to the resistance value of the resistor R0 externally connected to the terminal SEL0 from a plurality of different selection signals S11, S12, S13, S21, S22, and S23 when the read signal ΦREAD is in an active state. The plurality of different selection signals S11, S12, S13, S21, S22, and S23 are selection signal candidates pre-set in the decoder 270 in the selector 240.

[0140] The selector 240 includes a potential changing circuit 250, which changes the potential of the terminal SEL0 (selection potential VSEL0) through the reference resistor Rx and the switch LD2 according to the resistance value of the resistance element R0 externally connected to the terminal SEL0. The reference resistor Rx is inserted in series into the current path between the terminal SEL0 and the terminal VDD. When the switch LD2 is turned on by the read signal ΦREAD, the selection terminal SEL1 is pulled up and connected to the terminal VDD through the reference resistor Rx, so the selection potential VSEL1 changes according to the resistance value of the resistance element R0.

[0141] The selector 240 includes an encoder 260. The encoder 260 is a circuit that encodes the selection potential VSEL0 and outputs a code (LV21, LV22, LV23, LV24, LV25, LV26, LV27) corresponding to the resistance value of the resistor element R0. The encoder 260 has a plurality of series resistors inserted in series between the terminal VDD and the terminal VSS, and a plurality of comparators that compare the selection potential VSEL0 with a plurality of potentials V1, V2, V3, V4, V5, V6, and V7. When the switch LD1 is turned on by the read signal ΦREAD, a plurality of different potentials V1, V2, V3, V4, V5, V6, and V7 are generated by voltage division based on these plurality of series resistors.

[0142] The selector 240 includes a decoder 270. The decoder 270 is a circuit that converts the code (LV21, LV22, LV23, LV24, LV25, LV26, LV27) into a selection signal and an error signal ERROR. The decoder 270 outputs the selection signals S11, S12, S13, S21, S22, S23 and the error signal ERROR as a result of selecting the code (LV21, LV22, LV23, LV24, LV25, LV26, LV27). The selection signals S11, S12, S13, S21, S22, S23 and the error signal ERROR output from the decoder 270 are held in the latch circuit LT.

[0143] Fig.13 It is a table for explaining an operation example of the selector. The selector 240 becomes an operable state when the read signal ΦREAD is in an activated state (in this example, it is a high level "H"). In the operable state, the selector 240 outputs the result of selecting the selection potential VSEL0 corresponding to the resistance value of the resistance element R0 externally connected to the terminal SEL0 from the decoder 270. In the selector 240, when the read signal ΦREAD changes from an activated state to an inactivated state (in this example, it is a low level "L"), the selected result is held in the latch circuit LT. In addition, the read signal ΦREAD can be set to a pulse signal having an activated state shorter than the time when overcharging or overdischarging is detected when overcharging or overdischarging is detected. As a result, the power consumption suppression effect of the protection IC 102 can be effectively improved.

[0144] For example, when the selection potential VSEL0 is higher than the potential of the terminal VSS and lower than the potential V1, or higher than the potential V7 and lower than the potential of the terminal VDD, the selector 240 selects the error signal ERROR, and the error signal ERROR is held in the latch circuit LT. When the selection potential VSEL0 is higher than the potential V1 and lower than the potential V2, the selector 240 holds the selected selection signal S11 and the selected selection signal S21 in the latch circuit LT. In this way, the selector 240 selects the error signal ERROR according to the potential VSEL0. Fig.13 According to the correspondence relationship shown, the selection signal is selected and held in the latch circuit LT. Fig.13 The correspondence relationship shown is a set of correspondence between the overcharge detection voltage Vdet1 and the charge overcurrent detection voltage Vdet4 and the resistance value of the resistor element R0.

[0145] The other parts of the selection circuit 230 of the second embodiment may be Figures 6 to 10 The structure of the example.

[0146] Fig.14 1 is a circuit block diagram showing an example of a system including a secondary battery protection integrated circuit of the third embodiment. In the third embodiment, the description of the structure, function and effect similar to the above embodiment is omitted by citing the above description. The difference between the third embodiment and the first embodiment is that the switch circuit 203 is provided on the high-side power line 201. As a modified example of the third embodiment, as in the second embodiment, Fig.15 As shown, the selection terminal, the external resistance element and the selection circuit can be combined into one.

[0147] Fig.14 The system 503 shown has a battery device 403 and an electronic device 300. The battery device 403 has a secondary battery 210 and a battery protection device 603. The battery protection device 603 is a component having a substrate on which at least, for example, a protection IC 103 and resistor elements R1 and R2 are mounted. The protection IC 103 has, for example, a charge control terminal (terminal COUT), a discharge control terminal (terminal DOUT), a detection terminal (terminal VP), a power supply terminal (terminal VDD), a ground terminal (terminal VSS), a current detection terminal (terminal CS), a first selection terminal (terminal SEL1), a second selection terminal (SEL2), a first selection circuit 231, and a second selection circuit 232. The terminal VP has the same function as the terminal VM in the first embodiment.

[0148] The detection circuit 222 detects overcharge of the secondary battery 210 by monitoring the power supply voltage Vdd between the terminal VDD and the terminal VSS. The detection circuit 222 compares the power supply voltage Vdd with the overcharge detection voltage Vdet1, and generates an overcharge detection signal indicating that overcharge of the secondary battery 210 is detected when the power supply voltage Vdd is higher than the overcharge detection voltage Vdet1.

[0149] The detection circuit 222 detects the overcharge current of the secondary battery 210 by monitoring the potential difference ΔV1 between the terminal VDD and the terminal CS (or the terminal VP). The detection circuit 222 compares the potential difference ΔV1 with the overcharge current detection voltage Vdet4, and generates a charge overcurrent detection signal indicating that the overcharge current of the secondary battery 210 has been detected when the potential difference ΔV1 is higher than the overcharge current detection voltage Vdet4 with respect to the terminal VDD as a reference. In other words, when the voltage of the terminal CS (or the terminal VP) is higher than the overcharge current detection voltage Vdet4 with respect to the terminal VDD as a reference, the detection circuit 222 generates the overcharge current detection signal.

[0150] The detection circuit 222 detects overdischarge of the secondary battery 210 by monitoring the power supply voltage Vdd between the terminal VDD and the terminal VSS. The detection circuit 222 compares the power supply voltage Vdd with the overdischarge detection voltage Vdet2, and generates an overdischarge detection signal indicating that overdischarge of the secondary battery 210 is detected when the power supply voltage Vdd is lower than the overdischarge detection voltage Vdet2.

[0151] The detection circuit 222 detects the discharge overcurrent of the secondary battery 210 by monitoring the potential difference ΔV1 between the terminal VDD and the terminal CS (or the terminal VP). The detection circuit 222 compares the potential difference ΔV1 with the discharge overcurrent detection voltage Vdet3, and generates a discharge overcurrent detection signal indicating that the discharge overcurrent of the secondary battery 210 has been detected when the potential difference ΔV1 is lower than the discharge overcurrent detection voltage Vdet3 with respect to the terminal VDD as a reference. In other words, when the voltage of the terminal CS (or the terminal VP) is lower than the discharge overcurrent detection voltage Vdet3 with respect to the terminal VDD as a reference, the detection circuit 222 generates the discharge overcurrent detection signal.

[0152] As described above, the embodiments are described, but the above embodiments are presented as examples, and the present invention is not limited to the above embodiments. The above embodiments can be implemented in various other ways, and various combinations, omissions, substitutions, changes, etc. can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, and are included in the invention described in the claims and their equivalents.

[0153] For example, the arrangement positions of the charge control transistor TR1 and the discharge control transistor TR2 may be interchanged with respect to the positions shown in the figure. The switch circuit 203 may be built in the protection IC.

[0154] The secondary battery protection integrated circuit can also select a circuit characteristic or function different from the judgment voltage according to the resistance value of the resistor element externally connected to the selection terminal by the same structure or method as the above-mentioned structure or method for selecting the judgment voltage such as the overcharge detection voltage Vdet1. As an example of a circuit characteristic different from the judgment voltage, a delay time such as the detection delay time d1 can be cited.

[0155] Regarding the above embodiment, the following supplementary notes are further disclosed.

[0156] (Note 1)

[0157] The first determination voltage and the second determination voltage form a set corresponding to a resistance value of the first resistance element.

[0158] (Note 2)

[0159] The first determination voltage can be adjusted to any one of k voltage values.

[0160] The number of the plurality of fine-tuning elements is a natural number multiple of k.

[0161] Explanation of symbols

[0162] 101, 102, 103 protection IC

[0163] 201 Power cord

[0164] 202 Ground wire

[0165] 203 Switching Circuit

[0166] 210 Secondary battery

[0167] 211 Positive electrode

[0168] 212 Negative electrode

[0169] 221 Control Circuit

[0170] 222 Detection circuit

[0171] 230 Selection Circuit

[0172] 231 First selection circuit

[0173] 232 Second selection circuit

[0174] 240 Selector

[0175] 241 First Selector

[0176] 242 Second selector

[0177] 281 Adjustment Circuit

[0178] 300 Electronic equipment

[0179] 401, 402, 403 battery devices

[0180] 501, 502, 503 systems

[0181] 601, 602, 603 battery protection device

[0182] TR1 charging control transistor

[0183] TR2 discharge control transistor.

Claims

1. A secondary battery protection integrated circuit, characterized in that: have: A plurality of terminals, including: a power terminal, a ground terminal, a selection terminal and a control terminal; a selection circuit that changes a first determination voltage according to a resistance value of a first resistance element externally connected to the selection terminal; as well as A control circuit outputs a signal for controlling charging or discharging of the secondary battery from the control terminal based on a result of comparing a power supply voltage between the power supply terminal and the ground terminal with the first determination voltage.

2. A secondary battery protection integrated circuit, characterized in that: have: A plurality of terminals, including: a power terminal, a ground terminal, a selection terminal, a monitoring terminal and a control terminal; a selection circuit that changes a second determination voltage according to a resistance value of a second resistance element externally connected to the selection terminal; as well as A control circuit outputs a signal for controlling charging or discharging of the secondary battery from the control terminal based on a result of comparing a first potential difference between the monitoring terminal and a power supply terminal or a second potential difference between the monitoring terminal and a ground terminal with the second determination voltage.

3. A secondary battery protection integrated circuit, characterized in that: have: A plurality of terminals, including: a power terminal, a ground terminal, a first selection terminal, a second selection terminal, a monitoring terminal, and a control terminal; a selection circuit that changes a first determination voltage according to a resistance value of a first resistance element externally connected to the first selection terminal, and changes a second determination voltage according to a resistance value of a second resistance element externally connected to the second selection terminal; as well as A control circuit that outputs a signal for controlling the charging or discharging of the secondary battery from the control terminal based on a result of comparing the power supply voltage between the power supply terminal and the ground terminal with the first judgment voltage, and outputs a signal for controlling the charging or discharging of the secondary battery from the control terminal based on a result of comparing a first potential difference between the monitoring terminal and the power supply terminal or a second potential difference between the monitoring terminal and the ground terminal with the second judgment voltage.

4. A secondary battery protection integrated circuit, characterized in that: have: A plurality of terminals, including: a power terminal, a ground terminal, a selection terminal, a monitoring terminal and a control terminal; a selection circuit that changes the first determination voltage and the second determination voltage according to the resistance value of a first resistance element externally connected to the selection terminal; as well as A control circuit that outputs a signal for controlling the charging or discharging of the secondary battery from the control terminal based on a result of comparing the power supply voltage between the power supply terminal and the ground terminal with the first judgment voltage, and outputs a signal for controlling the charging or discharging of the secondary battery from the control terminal based on a result of comparing a first potential difference between the monitoring terminal and the power supply terminal or a second potential difference between the monitoring terminal and the ground terminal with the second judgment voltage.

5. The secondary battery protection integrated circuit according to any one of claims 1, 3 and 4, characterized in that: When the power supply voltage is higher than the first determination voltage, the control circuit outputs a signal from the control terminal to stop charging of the secondary battery.

6. The secondary battery protection integrated circuit according to any one of claims 1, 3 and 4, characterized in that: When the power supply voltage is lower than the first determination voltage, the control circuit outputs a signal from the control terminal to stop the discharge of the secondary battery.

7. The secondary battery protection integrated circuit according to any one of claims 2 to 4, characterized in that: When the first potential difference is higher than the second determination voltage with respect to the power supply terminal, the control circuit outputs a signal for stopping charging of the secondary battery from the control terminal.

8. The secondary battery protection integrated circuit according to any one of claims 2 to 4, characterized in that: When the first potential difference is lower than the second determination voltage with respect to the power supply terminal, the control circuit outputs a signal for stopping discharge of the secondary battery from the control terminal.

9. The secondary battery protection integrated circuit according to any one of claims 2 to 4, characterized in that: When the second potential difference is higher than the second determination voltage with respect to the ground terminal, the control circuit outputs a signal for stopping discharge of the secondary battery from the control terminal.

10. The secondary battery protection integrated circuit according to any one of claims 2 to 4, characterized in that: When the second potential difference is lower than the second determination voltage with respect to the ground terminal, the control circuit outputs a signal for stopping charging of the secondary battery from the control terminal.

11. The secondary battery protection integrated circuit according to claim 3 or 4, characterized in that: The first determination voltage includes a first detection voltage and a second detection voltage. The second determination voltage includes a third detection voltage and a fourth detection voltage, The control terminals include a charging control terminal and a discharging control terminal. When the power supply voltage is higher than the first detection voltage, the control circuit outputs a signal from the charge control terminal to stop charging of the secondary battery. When the power supply voltage is lower than the second detection voltage, the control circuit outputs a signal from the discharge control terminal to stop the discharge of the secondary battery. When the first potential difference is lower than the third detection voltage with respect to the power terminal as a reference, or when the second potential difference is higher than the third detection voltage with respect to the ground terminal as a reference, the control circuit outputs a signal from the discharge control terminal to stop the discharge of the secondary battery, When the first potential difference is higher than the fourth detection voltage with respect to the power terminal or when the second potential difference is lower than the fourth detection voltage with respect to the ground terminal, the control circuit outputs a signal to stop charging the secondary battery from the charge control terminal.

12. The secondary battery protection integrated circuit according to any one of claims 1, 3 and 4, characterized in that: When the resistance value of the first resistor element is higher than a first specified value or lower than a second specified value, the selection circuit outputs an error signal. When the error signal is output, the control circuit outputs a signal for stopping charging or discharging of the secondary battery from the control terminal.

13. The secondary battery protection integrated circuit according to claim 2 or 3, characterized in that: When the resistance value of the second resistor element is higher than a first specified value or lower than a second specified value, the selection circuit outputs an error signal. When the error signal is output, the control circuit outputs a signal for stopping charging or discharging of the secondary battery from the control terminal.

14. The secondary battery protection integrated circuit according to any one of claims 1, 3 and 4, characterized in that: The selection circuit comprises: Multiple fine-tuning elements; a selector that selects a plurality of elements corresponding to the resistance value of the first resistance element from among the plurality of fine-tuning elements; as well as An adjustment circuit adjusts the first determination voltage to a voltage value corresponding to a fine adjustment state of each of the plurality of elements selected by the selector.

15. The secondary battery protection integrated circuit according to claim 2 or 3, characterized in that: The selection circuit comprises: Multiple fine-tuning elements; a selector that selects a plurality of elements corresponding to the resistance value of the second resistance element from among the plurality of fine-tuning elements; as well as An adjustment circuit adjusts the second determination voltage to a voltage value corresponding to a fine adjustment state of each of the plurality of elements selected by the selector.

16. The secondary battery protection integrated circuit according to any one of claims 1, 3 and 4, characterized in that: The selection circuit comprises: a selector, which selects a selection signal corresponding to the resistance value of the first resistance element when the first read signal is in an active state; a holding circuit that holds the selection signal selected by the selector; as well as an adjustment circuit that adjusts the first determination voltage to a voltage value corresponding to the selection signal held by the holding circuit, When the first read signal is in an inactive state, supply of current to the selector is cut off.

17. The secondary battery protection integrated circuit according to claim 16, characterized in that: When overdischarge of the secondary battery is detected, the first read signal is in an active state, and when overdischarge of the secondary battery is not detected, the first read signal is in an inactive state.

18. The secondary battery protection integrated circuit according to claim 2 or 3, characterized in that: The selection circuit comprises: a selector, which selects a selection signal corresponding to the resistance value of the second resistance element when the second read signal is in an active state; a holding circuit that holds the selection signal selected by the selector; as well as an adjustment circuit that adjusts the second determination voltage to a voltage value corresponding to the selection signal held by the holding circuit, When the second read signal is in an inactive state, supply of current to the selector is cut off.

19. The secondary battery protection integrated circuit according to claim 18, characterized in that: The second read signal is a signal having an active state shorter than a time during which the overdischarge is detected when overdischarge of the secondary battery is detected.

20. A battery device, characterized in that: have: The secondary battery protection integrated circuit according to any one of claims 1 to 4; and The secondary battery.

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