KR20000011617A - Battery state monitoring circuit, battery device and electronic equipment on which the battery device is mounted - Google Patents

Abstract

PURPOSE: A cheap cell state observation circuit and a cheap cell pack having a high safety are provided. CONSTITUTION: The cell state observation circuit is composed of: a state observation device(14) for outputting the data of a second cell by observing at least one among the voltage and the current of the second cell; a control circuit(5) for outputting by converting the data of the second cell which is input from the state observation device; a data treatment device for calculating the data of the second cell input and converted from the control circuit and controlling the current control device based on the calculated result; a reset circuit for resetting the control circuit and the data treatment device or canceling the reset if it is necessary.

Description

Battery state monitoring circuit, battery device and electronic equipment on which the battery device is mounted}

The present invention relates to a battery device capable of calculating a residual capacity of a secondary battery such as a lithium ion secondary battery, and to improving the safety of the secondary battery and improving the accuracy of calculating the residual capacity of the secondary battery in a battery state monitoring circuit.

The conventional battery state monitoring circuit is known as shown in the circuit block diagram of FIG. For example, "battery pack, charger, charging system and charging method" of Japanese Patent Application Laid-open No. Hei 9-312172 discloses the structure shown in FIG. This relates to a battery device called a "smart battery system" or the like.

Lithium ion secondary batteries used in smart battery systems require overcurrent protection circuits because they do not have the same self-protection effect as nickel cadmium batteries. For this reason, the battery device is provided with a battery voltage monitoring circuit 4A for detecting battery voltage and a switching element 12A for stopping the charging operation from the outside.

In the battery device 22A, when the signals A3A and A4A are received from the current monitoring circuit 3A and the battery voltage monitoring circuit 4A, the microcomputer 6A serving as the information processing means is the secondary battery 7A. , 8A, 9A, 10A) monitor the battery voltage, charge current and discharge current respectively. Using the information (respective battery voltage, charge current and discharge current), the microcomputer 6A calculates the remaining capacity of the secondary batteries 7A, 8A, 9A, 10A, and functions as a switching element. The charging and discharging operations of the secondary batteries 7A, 8A, 9A, and 10A are controlled by controlling the on / off operations of the 12A and 13A.

The battery device 22A configured as described above displays the remaining capacity of the secondary batteries 7A, 8A, 9A, 10A, and stops the charging operation. The microcomputer 6A is inputted with the output voltages A3A and A4A from the current monitor circuit 3A and the battery voltage monitor circuit 4A, which are in accordance with the input voltages A3A and A4A. The charge current, discharge current and battery voltage of each of the secondary batteries 7A, 8A, 9A, 10A can be calculated, thereby calculating the residual capacity of the secondary battery. In addition, the microcomputer 6A performs on / off control of the switching elements 12A and 13A in accordance with the state (normal, overcharge, overdischarge, and overcurrent) of the secondary battery. In this way, the microcomputer 6A assumes the safety of the protection functions (overcharge protection, overdischarge protection, and overcurrent protection) of the battery device 22A.

As described above, it is necessary to provide a constant voltage as a power source to the microcomputer 6A, which is an important component in terms of configuration. For example, typical values for that voltage are 3.5V and 5.0V. The power source of the battery state monitoring circuit 14A is applied from the total battery voltage E2A of the secondary batteries 7A, 8A, 9A, and 10A in a general electric field. Since the total battery voltage E2A of the secondary battery changes depending on the state of the load 20A connected between the positive terminal 15A and the negative terminal 17A, the total battery voltage E2A of the secondary battery is the regulator 1A. Is controlled to 3.3V, 5.0V, etc., thereby applying a constant voltage to the microcomputer 6A.

However, even if a constant voltage E4A is output by the regulator 1A and applied to the microcomputer 6A, if the discharging operation of the battery device 22A continues, the total battery voltage E2A of the secondary battery becomes low. . Therefore, the constant voltage E4A output by the regulator 1A may be lower than the voltage at which the microcomputer 6A can safely operate. In the worst case, a phenomenon commonly referred to as "runaway" of the microcomputer 6A occurs. When the microcomputer 6A is runaway, not all control operations are performed including the on / off operation of the switching elements 12A and 13A, so that the safety of the battery device 22A is not guaranteed at all.

Typically, the voltage detection circuit 2A is connected to the power supply of the microcomputer 6A so that the microcomputer 6A does not run away. The voltage detection circuit 2A is composed of, for example, a comparator and a reference voltage, and its output voltage is designed to change when the input voltage becomes a predetermined set voltage. In Fig. 2, when the output voltage 4A of the regulator 1A is lower than the predetermined set voltage (reset detection voltage), the output of the voltage detection circuit 2A changes from high to low. The microcomputer 6A stops operating to prevent a malfunction when the output of the voltage detection circuit 2A changes. This control method is called "reset". The reset detection voltage of the microcomputer is the lowest operating voltage at which the microcomputer 6A does not malfunction (runaway), and in the case of a microcomputer with a 5V input normally, the reset detection voltage is set to about 4.6V.

Then, when the power supply voltage increases to the microcomputer 6A so that it can operate again, it is necessary to initialize the input signal to the microcomputer 6A once (hereinafter referred to as "power on clear"). For this reason, the power on clear circuit is disposed on the input signal line connected to the microcomputer 6A such that the power on clear is made only for a predetermined period after the microcomputer 6A starts to operate. In this state, the power on operation of the power on clear circuit needs to be synchronized with the time when the microcomputer starts to operate. If the start of operation of the microcomputer is not well synchronized with the power on clear, there is a possibility of malfunction. In this case, the microcomputer becomes inoperable and cannot secure the battery pack. Therefore, reliable operation is required for the power-on clear circuit.

However, in order to make the operation of the power-on circuit coincide with the operation start of the microcomputer, the operation start of the microcomputer must always be monitored, resulting in a complicated circuit structure. Since the cost is increased by providing the power-on circuit operated in this manner, in many conventional battery monitoring circuits and battery packs, the power-on clear circuit is usually replaced by the initialization function itself of the microcomputer 6A. However, in such a case, a microcomputer with a stable initialization function must be used, which leads to a problem that the selection of the microcomputer is limited.

In view of the foregoing, it is an object of the present invention to solve the problems of the prior art and to provide a high safety and low cost battery condition monitoring circuit and battery pack.

1 is a block diagram showing a battery state monitoring circuit and a battery device using the battery state monitoring circuit according to the present invention.

2 is a block diagram showing a conventional battery state monitoring circuit and a battery apparatus using the battery state monitoring circuit.

3 is a circuit diagram showing a battery state monitoring circuit and a regulator used in a battery device using the battery state monitoring circuit according to the present invention;

4 is a circuit diagram showing a battery state monitoring circuit and a current monitoring circuit used in a battery device using the battery state monitoring circuit according to the present invention;

Fig. 5 is a circuit diagram showing a battery state monitoring circuit and a battery voltage monitoring circuit used in a battery device using the battery state monitoring circuit according to the present invention.

Fig. 6 is a circuit diagram showing a battery state monitoring circuit and a control circuit used in a battery device using the battery state monitoring circuit according to the present invention.

7 is a timing diagram of a communication signal between a microcomputer and a control circuit used in a battery state monitoring circuit and a battery device using the battery state monitoring circuit according to the present invention;

Fig. 8 is an explanatory diagram showing a command signal for a control circuit in a microcomputer used in a battery state monitoring circuit and a battery device using the battery state monitoring circuit according to the present invention;

9 is an explanatory diagram showing operation timings of a battery state monitoring circuit and a battery device using the battery state monitoring circuit according to the present invention;

10 is an explanatory diagram showing a battery state monitoring circuit and a battery device operating flow using the battery state monitoring circuit according to the present invention;

Fig. 11 is a block diagram showing another example of a battery state monitoring circuit and a battery device using the battery state monitoring circuit according to the present invention.

12 is an explanatory diagram showing an embodiment of electronic equipment according to the present invention.

<Explanation of symbols for the main parts of the drawings>

1 regulator 2 voltage detection circuit

3: current monitor circuit 4: battery voltage monitor circuit

5: control circuit 6: microcomputer

7-10: Secondary Battery 11: Sense Resistor

12, 13, 36, 37, 41, 42: switching element

14: battery condition monitoring circuit 20: load

21 charger 22 battery device

23, 24: resistor 26: comparator

34: battery voltage monitor amplifier 35: comparator

39: serial / parallel conversion circuit 40: logic circuit

In order to solve the above problem, according to the present invention, the battery state monitoring circuit and the battery device are used in the case of a low power supply voltage at which the microcomputer is stopped or when the power supply voltage of the microcomputer rises from a low voltage (for example, a power supply voltage). If the power supply voltage rises from 0V, etc., once it returns from a state lower than the reset detection voltage, the charger is connected with the switching element turned off, and the power supply voltage of the microcomputer operates normally. After recognizing that the voltage has been sufficiently high (that the power supply voltage has reached the reset release voltage or higher), a command signal for turning on the switching element is transmitted from the microcomputer, thereby turning on the switching element. Is configured to.

Specifically, the battery state monitoring circuit is a switching element connected in series to the charge / discharge circuit in order to open / close the charge and discharge circuit in response to the switching control signal, and controls each part and outputs a control signal corresponding to the switch control signal. A microcomputer, a power supply voltage detection circuit connected to the power supply circuit of the microcomputer to detect that the power supply voltage of the power supply circuit has become a predetermined voltage or lower and output a reset signal to the microcomputer, and a power supply voltage detection circuit, the microcomputer and the switching And a control circuit connected to the element and outputting a switch control signal for turning off the switching element when a reset signal is input from the power supply voltage detection circuit.

In the above configuration, the control circuit is configured to output the switching control signal based on the control signal output from the microcomputer when the reset signal is not input.

Further, in the above configuration, the voltage of the charge and discharge circuit is input to the side connected to the secondary battery, the voltage of the charge and discharge circuit is input to the side connected to the charger, and the higher voltage among these voltages is selected and selected. A power switching circuit for supplying a voltage to the power circuit of the microcomputer may be further provided.

Furthermore, a battery device having a battery state monitoring circuit configured as described above can be constructed, wherein the secondary battery is connected to one end of a charge and discharge circuit of the battery state monitoring circuit, and a charging terminal for connection of a charger It is arranged at the other end of the charge and discharge circuit.

Moreover, the electronic equipment can be configured with a battery device configured as a power supply device, and in the electronic equipment, a CPU disposed in the electronic device can be used as information processing means of a battery state monitoring circuit in the battery device.

In order to realize the above-described configuration, according to the present invention, the control circuit for controlling the input signal and the output signal of the microcomputer is input to the microcomputer and the control circuit. The control circuit 5 has at least a "data reset function".

1 shows a structural example of a battery state monitoring circuit to which the present invention is applied and a battery pack using the circuit. Hereinafter, an embodiment of the present invention will be described with reference to FIG. 1.

The battery device has a structure in which a plurality of secondary batteries (for example, lithium ion secondary batteries) are connected in series or in parallel and provided with a battery state monitoring circuit and a switching element for controlling charging and discharging currents. In the example of FIG. 1, four secondary batteries 7 to 10 are connected in series, and the negative electrode of the secondary battery is connected to the sense resistor 11. In addition, the sense resistor 11 is connected to the negative terminal 17 of the battery device 22. The positive electrode of the secondary battery 7 is connected to a switching element 13 composed of a FET (field effect transistor) or the like. The switching element 13 is connected in series with the switching element 12. The switching element 12 is connected in series with the plus terminal 15 of the battery device 22. The switching elements 12 and 13 are used to control the charging operation of the charger 21 and the discharging operation of the secondary batteries 7 to 10. Prohibition of charging of the secondary batteries 7 to 10 may be performed by turning off the switching element 12. Discharge prohibition of the secondary batteries 8 to 10 can be performed by turning off the switching element 13. The switching elements 12 and 13 are connected between the cathode of the secondary battery 10 and the sense resistor 11. In this case, the type (n-channel, p-channel) or the like of the switching element (e.g., FET) needs to be appropriately changed in accordance with this connection. Similarly, the sense resistor 11 can be connected to the plus terminal 15 side of the battery device 22.

The battery state monitoring circuit 14 is composed of a regulator 1, a voltage detecting circuit 2, a current monitoring circuit 3, a battery voltage monitoring circuit 4, a control circuit 5, a microcomputer 6, and the like. .

The regulator 1 is composed of, for example, resistors 23 and 24, a reference voltage 25, a comparator 26 and a p-channel driver 27, and the output voltage E4 even if the input voltage E3 varies. ) Is always kept constant (e.g., 3.5V or 5V). In addition, the control signal B1 allows the output of the regulator 1 to be controlled on / off.

The output of the regulator 1 is connected to the voltage detection circuit 2. The voltage detection circuit 2 is composed of a comparator and a reference voltage, for example, as indicated by a rectangle indicated by a dotted line in FIG. 1, and the output voltage of the voltage detection circuit 2 is such that an input voltage becomes a predetermined set voltage. When it is changed. In Fig. 1, when the output voltage E4 of the regulator 1 is at or below a predetermined set voltage (reset detection voltage), the output RS of the voltage detection circuit 2 changes from high to low. The microcomputer 6 can stop the operation when the output RS changes, thereby preventing malfunction. Usually this control method is called "reset". The reset detection voltage of the microcomputer is the minimum operating voltage at which the microcomputer does not malfunction. In the case of a microcomputer with a 5V input, the reset detection voltage is usually set to about 4.6V.

The current monitor circuit 3 is a circuit for amplifying a voltage appearing between both ends of the monitoring resistor 11 by a charge and discharge current to a voltage that can be read by the microcomputer 6 and outputting it to the control circuit 5. Since the resistance of the sense resistor 11 is generally as small as several tens of mΩ, the current monitor circuit 3 amplifies the voltage across the sense resistor 11 several tens to hundreds of times and outputs it to the control circuit 5. 4 shows a structural example of the current monitor circuit 3. Reference numerals G1 and G2 denote terminals for connecting the sense resistors. The voltage appearing across the sense resistor is amplified by the charge current monitor amplifier 28 and the discharge current monitor amplifier 29. The signal B3 is a signal used to switch the on / off states of the switching element 30 and the switching element 31, and the voltage proportional to the charging current or the voltage proportional to the discharge current is connected to the terminals by switching the switching elements. It is output as (A3).

The battery voltage monitor circuit 4 converts each voltage of the secondary batteries 7 to 10 into a voltage that can be read by the microcomputer 6 and outputs it. 5 shows a structural example of the battery voltage monitor circuit 4. The battery voltage monitor circuit 4 is a circuit composed of a switching switching circuit 33, a battery voltage monitor amplifier 34, and the like. Each battery voltage of the secondary battery is selected by the switching switching circuit 33, and the selected battery voltage is converted by the battery voltage monitor amplifier 34 into a voltage which can be easily read by the microcomputer 6, and then the voltage ( V4) is output to one signal line. The control signal B4 is a signal controlled by the microcomputer 6, which battery is to be selected by the control signal B4, and the voltage of each battery is continuously output as one signal line. do. Although the control signal B4 is shown as one line in FIG. 5, it may be composed of a plurality of signal lines. 5 is a schematic representation of a switch in the switching switching circuit 33, and any structure may be used as long as the switch is configured such that each of the battery voltages can be output.

The control circuit 5 has a "power supply voltage switching function", a communication function with a microcomputer and a control function for each control block ", an" analog signal switching function ", and a" data reset function ".

6 shows an example of the structure of the control circuit 5. The " power supply voltage switching function " of the control circuit 5 compares the voltage E1 of the charger with the total battery voltage E2 of the secondary batteries with a comparator 35, and based on the result the switching elements 36, 37 ), And outputs its higher voltage to E3 as the power supply voltage of the regulator 1.

The "communication function with the microcomputer and the control function for each circuit block" means that the serial / parallel conversion circuit 39 converts the serial data signal DA (from the microcomputer 6) into the parallel data signals D5 to D0. The parallel circuit 40 converts these parallel data signals into control signals B1, B4, F1, F2, and H for each circuit block.

The communication signal from the microcomputer 6 is composed of, for example, a timing clock signal TK and a serial data signal DA, as shown in FIG. 7, and when the timing clock signal TK is high, the serial data signal ( DA) is a command signal transmitted from the microcomputer 6. In the example of FIG. 7, one instruction consists of 6 bit serial data. The time axis of the signal is from right to left, D0 is a previous signal in time and D5 is a later signal in time. In this example, assume that high is "1" and low is "0", and D5 to D0 represent data of "11010".

8 shows an example of a 6 bit instruction. For example, when the battery state monitoring circuit 14 is initialized (reset), the data of " 0 " is transferred from the microcomputer 6 as D5 to D0. When monitoring the charging current, the data of " 101100 " is transmitted from the microcomputer 6 as D5 to D0. Although the instructions of the microcomputer 6 of FIGS. 7 and 8 are formed with 6 bits, the instructions may not be formed with 6 bits. In addition, although the number of signals transmitted from the microcomputer is two consisting of TK and DA, it may not be two. In addition, the command sent from the microcomputer is not limited by FIG. 8, and the logic of the high and low may be different.

The logic circuit 40 of FIG. 6 operates to transmit control signals (e.g., B3, etc.) to each circuit block (e.g., the current monitor circuit 3, etc.), and the instruction shown in FIG. The logical data (for example, NAND circuit, NOR circuit, inverter, etc.) is used to logically configure the parallel data signals D5 to D0 so as to correspond to the above. For example, in the case of the command of " 101100 " of the charge current monitor, only B3 is set high, and the other control voltages B1, B4, F1, F2, and H are constituted by unchanged logic.

The "analog signal switching function" of the control circuit 5 represents the output signal A3 of the current monitor circuit 3 and the output signal A4 of the battery voltage monitor circuit 4 shown in FIG. The switching elements 41 and 42 are switched by the signal H processed by the circuit 40 to be transmitted to the microcomputer 5 as an analog signal AN. The output of the analog signal AN is designed to select any one of the charging current, the discharge current and the respective battery voltage in response to the signals TK and DA from the microcomputer 6.

The "data reset function" of the control circuit 5 is shown in FIG. 6 by a signal RS which changes when the output voltage E4 of the regulator 1 of FIG. 1 is lower than the reset detection voltage of the microcomputer 6. All of the parallel data signals D5 to D0 of one serial / parallel conversion circuit 39 are set to 0 (initialization of data in the control circuit 5). Then, in the initialized state, the logic of the logic circuit 40 of FIG. 6 is designed to turn off the switching elements 12, 13 that control the charging and discharging operations shown in FIG.

When the "data reset function" of the control circuit 5 is performed, the input signal AN to the microcomputer 6 goes low. This state is maintained until the output voltage E4 of the regulator 1 exceeds the reset detection voltage of the microcomputer 6 so that the microcomputer 6 starts to operate and requests predetermined data. Thus, power on clear is always performed when the microcomputer begins to operate. Even if the data request function of the microcomputer 6 does not operate and does not operate, the low state of the input signal AN is maintained. Therefore, the microcomputer 6 does not malfunction by inputting the error input signal AN, thereby improving the safety of the battery pack. That is, in the present invention, the signal RS can enable the reset of the microcomputer 6 and the power-on clear of the input signal AN to be controlled simultaneously.

The microcomputer 6 according to the embodiment of the present invention shown in FIG. 1 has a function of monitoring the battery voltage, the charging current and the discharge current of the secondary batteries 7 to 10, and the secondary batteries 7 to 10 from these information. It has the function of calculating the residual capacity of. The microcomputer 6 has an A / D conversion, arithmetic operation function, communication function, etc., and sends command signals TK, DA to the control circuit 5 to control the circuit 5, and the current monitor circuit 3 ) And the analog signals A3 and A4 are output from the battery voltage monitor circuit 4 as analog signals AN. In addition, the microcomputer 6 integrates the charging current and the discharging current, inputs the analog signal AN, performs A / D conversion on the input analog signal AN, and then, for each battery voltage, Calculate the residual capacity of the battery.

Furthermore, the microcomputer 6 monitors the respective battery voltages and the discharge currents of the secondary batteries 7 and performs on / off operations of the switching elements 12 and 13 in accordance with the voltages and discharge currents of the respective secondary batteries. By controlling, the battery device 22 is loaded.

Since the microcomputer 6 assumes the safety of the battery device 22's protection functions (overcharge protection, overdischarge protection, and overcurrent protection), the battery device 22 causes the microcomputer 6 to stop or fail. In the worst case where there is no protection, there is a possibility of explosion. In such a situation, when the low power supply voltage at which the microcomputer 6 is stopped or when the power supply voltage of the microcomputer 6 rises from the low voltage (for example, from a state in which the power supply voltage is once lower than the reset detection voltage) In the case of returning, when the power supply voltage of the microcomputer 6 rises from 0 V, or the like), or the voltage detection circuit 2 in order to safely control the battery device 22 even when the microcomputer 6 stops or fails. The reset is performed to turn off the switching elements 12 and 13. Then, after the charger 21 is connected and the power supply voltage E4 to be applied to the microcomputer 6 rises to a voltage at which the microcomputer 6 operates normally or higher, the command signal is supplied to the microcomputer ( 6, it is transmitted to the control circuit 5 to turn on the switching elements 12 and 13. For example, in the example of FIG. 8, the microcomputer 6 sends the command signal "100111" to the control circuit 5 to turn on the switching elements 12, 13 for the first time.

This operation keeps the switching elements 12 and 13 turned off as long as the microcomputer 6 is transmitting a command to turn on the switching elements 12 and 13, so that the charging or discharging operation can be performed. The disabling state is maintained continuously even if the microcomputer 6 stops or malfunctions and thus cannot be controlled. In this way, even when the microcomputer 6 is stopped or broken, the safety of the battery device 22 can be ensured.

In addition, when the microcomputer 6 returns to the reset state, the switching elements 12 and 13 start from the state in which the switching elements 12 and 13 are turned off, and then turn on after the microcomputer 6 is completely safely operated. Because of this, the charge current or discharge current which cannot be measured is eliminated, thereby improving the accuracy of calculating the residual capacity of the secondary battery.

Next, the operation of this embodiment will be described with reference to FIGS. 9 and 10. Fig. 9 shows the operation timing of this embodiment. The horizontal axis represents time and the vertical axis represents voltage, showing the total battery voltage and the output voltage of the regulator 1. During the period of time 0 to ta, current is supplied from the battery device 22 to the load 20, and the total battery voltage drops over time. At time ta, the entire battery voltage becomes equal to the output voltage of the regulator 1. At time taa, the output voltage of the regulator 1 reaches the detection voltage of the voltage detection circuit 2 (reset detection voltage of the microcomputer). At this time, the output voltage RS of the voltage detection circuit 2 is changed to reset the microcomputer 6 so as to reset the input signal AN to the microcomputer 6 to low and also to reset the control circuit 5. .

Then, at time tb, the charger 21 is connected. In the battery device 22 configured as shown in FIG. 1, as soon as the charger 21 is connected, the voltage of the charger or the higher of the total battery voltage is applied to the input of the regulator 1. If the voltage of the charger 21 is higher than the desired output voltage of the regulator 1 (e.g., 3.3V or 5V), then the regulator 1 will be set to the desired constant voltage (e.g., as soon as the charger 21 is connected). 3.3V or 5V) is applied to the microcomputer 6. The voltage detection circuit 2 monitors the output voltage of the regulator 1, and the output voltage of the regulator 1 is such that the voltage at which the microcomputer 6 operates normally (reset release voltage or higher of the microcomputer) is determined. The output RS of the voltage detection circuit 2 is inverted, and the microcomputer 6 starts to operate. At this time, the input signal AN is still kept low. Then, after recognizing that the microcomputer 6 is normal through self-diagnosis, the microcomputer 6 sends a predetermined data request command to the control circuit 5 at time tc. The control circuit 5 processes the signal and then sends data to the current monitor circuit 3 and the battery voltage monitor circuit 4. In response to the received data, the current monitor circuit 3 and the battery voltage monitor circuit 4 output corresponding data back to the control circuit 5. When data is first received, the control circuit 5 outputs a predetermined signal AN to the microcomputer 6. That is, since the power-on clear is released after the microcomputer 6 is in a stable operation, the accuracy of calculating the residual capacity of the secondary battery is improved.

FIG. 10 is a diagram illustrating an operation flow of FIG. 9. At time ta, the total battery voltage becomes equal to the regulator's output voltage by supplying current to the load, after which the discharge operation proceeds, and the output voltage of the regulator 1 is detected by the voltage detection circuit 2 (reset detection). Voltage) or lower at time taa, the reset signal RS goes high to high.

The microcomputer 6 is reset in accordance with the reset signal RS, and at the same time the control circuit 5 resets the input signal AN to low.

Then, when the charger 21 is connected, since the voltage of the charger 21 (voltage higher than the pre-battery voltage or the desired voltage of the regulator 1) is applied to the input of the regulator 1, the regulator 1 The output voltage becomes a reset release voltage or higher (at a desired voltage).

Thereafter, the microcomputer 6 returns to the reset state and performs self-diagnosis. When NG is obtained as a result of the self-diagnosis of the microcomputer, the input signal AN remains low because a command for requesting predetermined data from the microcomputer 6 is not transmitted.

If OK is given as a result of the self-diagnosis of the microcomputer 6, a command for requesting predetermined data from the microcomputer 6 is transmitted to the control circuit 5. At this time, if no command is transmitted, the input signal AN remains low, and when the command is transmitted, the input signal AN becomes a predetermined value corresponding to the data request.

11 is a block diagram illustrating another embodiment of the present invention. In this embodiment, the microcomputer 6 is configured as a different component from the battery state monitoring circuit 14. The components and principles of operation are exactly the same as those of the embodiment described in FIG. In this way, in the battery device according to the present invention, it is effective to provide all the functions as one component (IC), and the same effect is obtained even if the microcomputer and the switching element are mounted on the substrate to provide a plurality of components. Obtained.

In the embodiment shown in Fig. 11, various types of microcomputers 6 can be combined together. When the microcomputer 6 is once reset and returned, if the unstable input signal AN remains intact, even if the microcomputer 6 which has not started operation is selected, no inconvenience occurs in the present invention. The present invention is very effective in that the range in which the microcomputer to be combined is selected is wide.

In the embodiment shown in FIG. 1 and FIG. 11, a configuration example in which each of the secondary batteries 7 to 10 is connected in series has been described. However, the present invention can be similarly applied even when a plurality of secondary batteries are connected in parallel.

According to the present invention, even if the microcomputer 6 is integrated with other circuit blocks (one chip) and it is difficult to distinguish the microcomputer 6 from other circuit blocks, the battery voltage, the charging current and the charge of the secondary battery A circuit block having a function of monitoring current and a function of calculating a residual capacity of a secondary battery from these information can be applied as a microcomputer.

12 is an explanatory diagram showing an embodiment of electronic equipment to which the battery device according to the present invention is mounted. In Fig. 12, the battery device 22 is assembled to a personal computer 99 in the form of a notebook, which is an electronic device, as a power source. The battery state monitoring circuit 14 is assembled to the battery device 2. In a lithium secondary battery mainly installed in a personal computer of a conventional notebook type, the risk of fire, explosion, etc. is pointed out because of the high responsiveness of lithium. That is, the safety of the notebook type personal computer is mainly determined by the safety of the battery device, and if the safety of the notebook type personal computer is improved, it is essential to improve the safety of the battery state monitoring circuit and the battery device. However, the battery state monitoring circuit and the battery apparatus of the present invention have high safety as described above, are optimal as a battery of a notebook type personal computer, and contribute greatly to the safety of a notebook type personal computer. Therefore, the present invention is applied to a personal computer in the form of a notebook assembled with a battery device.

In addition, the present invention is excellent in that the range for selecting microcomputers is wide, for example, it is possible to perform a battery remaining capacity calculation function with a microcomputer of a notebook personal computer. In this respect, the battery device of the present invention is largely related to electronic equipment assembled with the battery device, and thus the scope of application of the present invention is wide.

The notebook type personal computer 99 shown in FIG. 12 shows only one example of electronic equipment, and the present invention can be applied to electronic equipment other than the notebook type personal computer for the same reason.

As described above, in the battery state monitoring circuit and the battery apparatus according to the present invention, since the output signal of the voltage detection circuit 2A also functions as a power on clear signal, the power supply voltage of the microcomputer is low or the power supply of the microcomputer is low. When the voltage is rising in the low state, the input signal to the microcomputer can be set to the initial state. Therefore, high safety can be provided to the battery condition monitoring circuit, the battery pack or the electronic equipment in which the battery pack is assembled. In addition, the range of selection of microcomputers that can be incorporated into battery condition monitoring circuitry is broadened.

Claims (12)

A battery state monitoring circuit for controlling a current limiting means for adjusting a current of a secondary battery that can be charged and discharged, and for monitoring a state of the secondary battery, at least State monitoring means for monitoring at least one of voltage and current of the secondary battery and outputting information of the secondary battery; A control circuit for converting and outputting the secondary battery information input from the state monitoring means; Information processing means for calculating the secondary battery information inputted from the control circuit and converted and controlling the current limiting means based on the calculation result; And And a reset circuit for resetting or canceling the control circuit and the information processing means if necessary. The method of claim 1, wherein the control circuit outputs a predetermined initial value when a reset command is input from the reset circuit, releases the reset when the reset release command is input from the reset circuit, and converts the secondary battery information. And a secondary battery information request command from said information processing means for outputting. The battery state monitoring circuit according to claim 1 or 2, wherein the current limiting means includes a switching transistor, and is capable of turning on / off at least one of a charge current and a discharge current of the secondary battery. A secondary battery that can be charged and discharged and a current limiting means for adjusting the current of the secondary battery are connected between the plus terminal and the minus terminal, which are external terminals, The battery device as claimed in claim 1, wherein a battery condition monitoring circuit is provided to control the current limiting means and to monitor the condition of the secondary battery. A battery state monitoring circuit comprising information processing means and configured to control charging and discharging current to a secondary battery by turning on / off a switching element that controls charging and discharging current in response to a command signal from the information processing means. When the power supply voltage of the information processing means is lower than the predetermined voltage, or when the power supply voltage of the information processing means rises from a voltage lower than the predetermined voltage even if the power supply voltage of the information processing means is not lower than the predetermined voltage. And the switching element for controlling the charging and discharging current is kept in an off state, and the switching element is in an off state until the information processing means transmits a command to turn on the switching element. Supervisory circuit. A positive terminal, a negative terminal, a switching element for controlling charging and discharging currents, a secondary battery, a sensing resistor for monitoring the charging and discharging currents, and a battery state monitoring circuit, and the control unit for controlling the charging and discharging currents. In the switching device is a battery device that is turned on / off to control the charge and discharge current for the secondary battery, When the power supply voltage of the information processing means is lower than the predetermined voltage, or when the power supply voltage of the information processing means rises from a voltage lower than the predetermined voltage even if the power supply voltage of the information processing means is not lower than the predetermined voltage. And the switching element for controlling the charging and discharging current is kept in an off state, and the switching element is in an off state until the information processing means transmits a command to turn on the switching element. . In the battery state monitoring circuit, A switching element connected in series with a charging and discharging circuit to open / close the charging and discharging circuit in response to a switching control signal; Information processing means for controlling the units and outputting a control signal corresponding to the switching control signal; A power supply voltage detection circuit connected to the power supply circuit, for detecting that the power supply voltage of the power supply circuit is lower than a predetermined voltage and outputting a reset signal to the information processing means; And A control circuit connected to the power supply voltage detection circuit, the information processing means and the switching element, and outputting the switching control signal to turn off the switching element when the reset signal is input from the power supply voltage detection circuit. A battery state monitoring circuit, characterized in that. In the battery state monitoring circuit, A switching element connected in series with a charging and discharging circuit to open / close the charging and discharging circuit in response to a switching control signal; Information processing means for controlling the units and outputting a control signal corresponding to the switching control signal; A power supply voltage detection circuit connected to the power supply circuit, for detecting that the power supply voltage of the power supply circuit is lower than a predetermined voltage and outputting a reset signal to the information processing means; And Connected to the power supply voltage detection circuit, the information processing means and the switching element, the switching element is turned off when the reset signal is input from the power supply voltage detection circuit, and the information processing when the relet signal is not input; And a control circuit for outputting the switch control signal based on the control signal output from the means. The voltage of the said charge and discharge circuit is input to the side connected to a secondary battery, and the voltage of the said charge and discharge circuit is input to the side connected to a charger, The higher voltage among these voltages is provided. And a power supply voltage switching circuit for selectively supplying the selected voltage to the power supply circuit of the information processing means. The charging terminal according to any one of claims 7 to 9, wherein a secondary battery is connected to one end of said charge and discharge circuit of said battery state monitoring circuit and said charger is connected to the other end of said charge and discharge circuit. Battery status monitoring circuit, characterized in that provided. An electronic device comprising the battery device as claimed in claim 4. 12. The electronic equipment according to claim 11, wherein the electronic equipment includes a CPU, and the CPU functions as the information processing means of the battery state monitoring circuit.