JP2017207453A - Semiconductor device, battery monitoring system, and diagnosis method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable detection of abnormality becoming obvious when varying potential to be applied to main wiring targeted for a diagnosis in a self-diagnosis of a semiconductor device.SOLUTION: A semiconductor device includes: a plurality of main wiring that are provided correspondingly to each node generating mutually different potential of a plurality of series-connected battery cells; a series-connection resistance circuit that includes a plurality of series-connected resistance elements, and has one end connected to a power source line; a first current source that is connected to the other end of the series-connection resistance circuit; a second current source that is connected to an end part on a high potential side of a specific resistance element of the plurality of resistance elements, or a part of potential higher than the end part on the high potential side of the specific resistance element of the series-connection resistance circuit; a first switch that is provided between one of a pair of diagnosis target wiring of the plurality of main wiring and one end of the specific resistance element; and a second switch that is provided between the other of the pair of diagnosis target wiring of the plurality of main wiring and the other end of the specific resistance element.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a semiconductor device, a battery monitoring system, and a diagnostic method.

  A battery monitoring system that monitors the state of each battery cell of an assembled battery including a plurality of battery cells connected in series is known. For example, in Patent Document 1, a plurality of power supply lines connected to each of a plurality of batteries connected in series, a selection unit that selects two power supply lines from the plurality of power supply lines, and a selection unit selected When an electrical signal flowing through two power supply lines is input, a measurement unit that converts a difference between the electrical signals flowing through the two power supply lines into a digital signal and outputs the digital signal, and a digital signal output from the measurement unit A calculation means for performing a predetermined calculation and outputting an electric signal according to the calculation result; a power supply line through which an electric signal according to a first reference voltage flows from a plurality of power supply lines; and a first reference voltage; First control for controlling the selection means so as to select a power supply line through which an electric signal corresponding to a different second reference voltage flows, and an electric signal corresponding to the second reference voltage are converted into a digital signal and output. Control measuring means And control means for performing a second control, the semiconductor circuit having a listed that.

  Patent Document 2 includes a plurality of power supply lines, selection means, measurement means, and calculation means similar to those described in Patent Document 1 above, and a second reference voltage obtained by dividing the first reference voltage. An assembled battery system including a reference voltage divider for supplying power to a power line is described. In this assembled battery system, the self-diagnosis of the measuring means includes the difference between the first reference voltage and the second reference voltage output from the measuring means, and the second reference voltage smaller than the second reference voltage and the second reference voltage. This is performed depending on whether or not the addition value of the difference from the reference voltage 3 is a value corresponding to the first reference voltage.

JP 2013-195157 A JP 2014-240818 A

  The semiconductor device for battery monitoring includes a plurality of main wirings provided corresponding to each of nodes generating different potentials of a plurality of battery cells connected in series. Some of such semiconductor devices have a self-diagnosis function that detects their own abnormality. In the self-diagnosis, for example, a voltage is applied to a pair of main wirings selected from a plurality of main wirings, and it is determined whether or not a measured value of a voltage generated between the pair of main wirings is appropriate.

  As a method for effectively detecting an abnormality of a semiconductor device, for example, the main wiring when the potential applied to each main wiring is increased or decreased while keeping a diagnostic voltage applied between a pair of main wirings to be diagnosed constant. A method for monitoring voltage fluctuations occurring between them is conceivable. In those described in Patent Document 1 and Patent Document 2, it is difficult to perform self-diagnosis by the above-described method, and an abnormality that is manifested when the potential applied to each main wiring is changed is detected. It was difficult.

  The present invention has been made in view of the above points, and is a self-contained semiconductor device including a plurality of main wirings provided corresponding to respective nodes that generate different potentials in a plurality of battery cells connected in series. An object of the present invention is to enable detection of an abnormality that becomes apparent when a potential applied to a main wiring to be diagnosed is changed in diagnosis.

  A semiconductor device according to the present invention includes a plurality of main wirings provided corresponding to respective nodes that generate different potentials of a plurality of battery cells connected in series, and a plurality of resistance elements connected in series. A series resistance circuit connected to the power supply line, a first current source connected to the other end of the series resistance circuit, an end on the high potential side of a specific resistance element among the plurality of resistance elements, Alternatively, a second current source connected to a connection portion between resistance elements having a higher potential than an end portion on the high potential side of the specific resistance element of the series resistance circuit, and a pair of the plurality of main wirings A first switch provided between one of the diagnosis target wirings and one end of the specific resistance element; and between the other of the pair of diagnosis target wirings and the other end of the specific resistance element. A second switch.

  Another semiconductor device according to the present invention includes a plurality of main wirings provided corresponding to respective nodes that generate different potentials of a plurality of battery cells connected in series, and a plurality of resistance elements connected in series. A series resistance circuit having one end connected to a power supply line, a first current source connected to the other end of the series resistance circuit, and an end on the high potential side of a specific resistance element among the plurality of resistance elements Or a second current source that is selectively connected to any one of the connecting portions between the resistance elements having a higher potential than the high-potential side end of the specific resistance element of the series resistance circuit, A first switch provided between one of the pair of diagnosis target wirings of the plurality of main wirings and one end of the specific resistance element; and the other of the pair of diagnosis target wirings and the specific resistance element. And a second switch provided between the other end.

  A battery monitoring system according to the present invention includes a plurality of battery cells connected in series, a plurality of main wires provided corresponding to each of the nodes that generate different potentials of the battery cells, and a plurality of cells connected in series. A series resistance circuit including a resistance element, one end of which is connected to a power supply line; a first current source connected to the other end of the series resistance circuit; and a height of a specific resistance element among the plurality of resistance elements A second current source connected to an end portion on the potential side, or a connection portion between resistance elements having a higher potential than an end portion on the high potential side of the specific resistance element of the series resistance circuit; A first switch provided between one of the pair of diagnosis target wirings of the main wiring and one end of the specific resistance element; the other of the pair of diagnosis target wirings and the other end of the specific resistance element A second switch provided between the plurality of switches and the plurality of switches A switch group including a plurality of switches for switching connection and disconnection of each main wiring to the first node or the second node, and a difference between the potential of the first node and the potential of the second node A voltage output unit that outputs a voltage according to the pair of the first switch and the second switch, the first current source is turned on, and the second current source is turned off. The switch group is controlled so that one of the diagnosis target wirings is connected to the first node, and the other of the pair of diagnosis target wirings is connected to the second node. A first state in which a voltage corresponding to a difference between the potential of the node and the potential of the second node is output; the first switch and the second switch are turned on; and the first current source is turned on State, the second current The switch group is controlled so that one of the pair of diagnosis target wirings is connected to the first node and the other of the pair of diagnosis target wirings is connected to the second node while the switch is turned on. And a controller that sequentially forms a second state in which a voltage corresponding to a difference between the potential of the first node and the potential of the second node is output from a voltage output unit.

  Another battery monitoring system according to the present invention includes a plurality of main wirings provided corresponding to nodes that generate different potentials of a plurality of battery cells connected in series, and a plurality of resistance elements connected in series. A series resistor circuit having one end connected to the power supply line, a first current source connected to the other end of the series resistor circuit, and a high potential side of a specific resistor element among the plurality of resistor elements A second current source that is selectively connected to either the end portion or a connection portion between resistance elements having a higher potential than the end portion on the high potential side of the specific resistance element of the series resistance circuit; A first switch provided between one of the pair of diagnosis target wirings of the plurality of main wirings and one end of the specific resistance element; and the other of the pair of diagnosis target wirings and the specific resistance element. A second switch provided between the other end, and A first switch group including a plurality of switches each having one end connected to a connection portion between adjacent resistance elements of the column resistance circuit and each other end connected to the second current source; A second switch group including a plurality of switches for switching connection and non-connection of each of the main wirings to the first node or the second node; the potential of the first node; and the potential of the second node A voltage output unit that outputs a voltage corresponding to the difference between the first switch and the second switch, the first switch and the second switch are turned on, and each of the plurality of switches constituting the first switch group is turned off, One of the pair of diagnosis target wirings is connected to the first node while the current source of the pair is turned on and the second current source is turned off, and the other of the pair of diagnosis target wirings is connected to the second node. To connect to the second A first state of controlling a switch group to output a voltage according to a difference between the potential of the first node and the potential of the second node from the voltage output unit; the first switch; 2 is turned on, any one of the plurality of switches constituting the first switch group is turned on, the first current source is turned on, and the second current source is turned on. The voltage output unit is configured to control the second switch group to connect one of a pair of diagnosis target wires to the first node and to connect the other of the pair of diagnosis target wires to the second node. And a controller that sequentially forms a second state in which a voltage corresponding to a difference between the potential of the first node and the potential of the second node is output.

  The diagnostic method according to the present invention includes a plurality of main wirings provided corresponding to respective nodes that generate different potentials of a plurality of battery cells connected in series, and a plurality of resistance elements connected in series. A method for diagnosing a semiconductor device including a series resistance circuit connected to a power supply line, wherein a voltage generated at both ends of a specific resistance element among the plurality of resistance elements by flowing a current through the series resistance circuit. Applying a voltage between a pair of diagnosis target wires of the plurality of main wires to measure a voltage between the pair of diagnosis target wires, and maintaining a magnitude of a current flowing through the specific resistance element Measuring a voltage between the pair of diagnosis target wirings by changing a potential at one end of the specific resistance element and applying a voltage generated between both ends of the specific resistance element between the pair of diagnosis target wirings; Including the.

  In self-diagnosis of a semiconductor device including a plurality of main wirings provided corresponding to each of nodes that generate different potentials in a plurality of battery cells connected in series, the potential applied to the main wiring to be diagnosed is changed. It is possible to detect an abnormality that becomes apparent in the event of a failure.

It is a block diagram which shows the structure of the battery monitoring system which concerns on embodiment of this invention. It is a figure which shows the structure of the test | inspection circuit based on embodiment of this invention. It is a flowchart which shows the flow of operation | movement at the time of the self-diagnosis of the semiconductor device which concerns on embodiment of this invention. It is a figure which shows the 1st state of the test | inspection circuit based on embodiment of this invention. It is a figure which shows the 2nd state of the test | inspection circuit which concerns on embodiment of this invention. It is a figure which shows the 3rd state of the test | inspection circuit based on embodiment of this invention. It is a figure which shows the structure of the test | inspection circuit which concerns on other embodiment of this invention. It is a figure which shows the 1st state of the test | inspection circuit which concerns on other embodiment of this invention. It is a figure which shows the 2nd state of the test | inspection circuit which concerns on other embodiment of this invention. It is a figure which shows the 3rd state of the test | inspection circuit based on other embodiment of this invention. It is a figure which shows the structure of the test | inspection circuit which concerns on other embodiment of this invention. It is a block diagram which shows the structure of the battery monitoring system which concerns on other embodiment of this invention. It is a figure which shows the structure of the switch group for battery cell selection which concerns on other embodiment of this invention.

  Hereinafter, an example of an embodiment of the present invention will be described with reference to the drawings. In the drawings, the same or equivalent components and parts are denoted by the same reference numerals, and repeated descriptions are omitted as appropriate.

[First embodiment]
FIG. 1 is a block diagram showing a configuration of a battery monitoring system 1 according to an embodiment of the present invention. The battery monitoring system 1 includes a battery pack 200 including a plurality of battery cells C ₂ ,..., C _n−1 , C _n and C _{n + 1} connected in series, and each battery cell C _{2 ,. The} semiconductor device 100 is configured to monitor the states of ₋₁ , C _n and C _{n + 1} .

The semiconductor device 100 includes input terminals T _{1 to} T _{n + 1} provided corresponding to nodes that generate different potentials of the battery cells C _{2 to} C _{n + 1} , and an inspection circuit connected to the input terminals T _{1 to} T _{n + 1.} 10, a control unit 110 connected to the inspection circuit 10, a storage unit 120 connected to the control unit 110, and an output terminal T _out .

The semiconductor device 100 has a cell voltage measurement function for measuring each cell voltage of the battery cells C _{2 to} C _{n + 1} input via the input terminals T _{1 to} T _{n + 1,} and whether or not an abnormality has occurred in the inspection circuit 10. Has a self-diagnosis function to diagnose. The control unit 110 supplies the control signal to the inspection circuit 10 to control the operation of the inspection circuit 10, whereby the cell voltage measurement function and the self-diagnosis function are realized. The control unit 110 receives data output from the inspection circuit 10. The storage unit 120 stores data output from the inspection circuit 10 under the control of the control unit 110. For example, in response to a request from a host system (not shown), the control unit 110 reads out data stored in the storage unit 120 and outputs the data from the output terminal _Tout . Further, the control unit 110 diagnoses whether or not an abnormality has occurred in the inspection circuit 10 based on the data output from the inspection circuit 10, and outputs the diagnosis result from the output terminal _Tout .

FIG. 2 is a diagram showing a detailed configuration of the inspection circuit 10. The inspection circuit 10 has a plurality of main wirings W _{1 to} W _{n + 1} provided corresponding to each of the input terminals T _{1 to} T _{n + 1} . That is, the main wirings W _{1 to} W _{n + 1} are provided corresponding to the nodes that generate different potentials in the battery cells C _{2 to} C _{n + 1} connected in series. The inspection circuit 10 includes a battery cell connection switch group 11, a power supply connection switch 12, a power supply connection switch group 13, a battery cell selection switch group 20, a level shifter 30, a reference power supply 40, a voltage dividing circuit 50, and an AD converter. 70, a series resistance circuit 80, a reference current source 81, an offset current source 82, a bypass switch 90, and switches 61 to 64.

The battery cell connection switch group 11 includes a plurality of switches 11 _{1 to} 11 _{n + 1} provided corresponding to each of the input terminals T _{1 to} T _{n + 1} and each of the main wirings W _{1 to} W _{n + 1} . . Each of the plurality of switches 11 _{1 to} 11 _{n + 1} has one end connected to the corresponding input terminal T _{1 to} T _{n + 1} and the other end connected to the corresponding main wiring W _{1 to} W _{n + 1} . For example, the switch 11 _n has one end connected to the input terminal T _n and the other end connected to the main wiring W _n , and when the switch 11 _n is turned on, the main wiring W _n and the input terminal T _n are turned on. DOO potential of the corresponding node of each node in the cell to the main wiring W _n are connected is applied.

Power connection switch 12 is connected to the main wiring W _2, one end of the corresponding and the other end connected to the power supply line W _H on the high potential side. Power connection switch 12 is the potential of the power supply wire W _H on the high potential side is applied to the main wiring W ₂ by the ON state.

The power supply connection switch group 13 includes a plurality of switches 13 _{1 to} 13 _{n + 1} provided corresponding to each of the plurality of main wirings W _{1 to} W _{n + 1} . Among the plurality of switches constituting the power connection switch group 13, the switch 13 ₁ is connected to the main wiring W ₁ having one end corresponding and the other end connected to the power supply line W _L on the low potential side. The potential of the power supply wiring W _L on the low potential side is applied to the main wiring W ₁ by the switch 13 ₁ is turned on.

Among the plurality of switches constituting the second power connection switch group 13, the switches 13 _{2 to} 13 _{n + 1} are respectively connected at one end to the corresponding main wirings W _{2 to} W _{n + 1} and the other end is connected to the series resistance circuit 80. Connected to the corresponding node. For example, one end of the switch 13 _n is connected to the main wiring W _n , and the other end is connected to a connection portion between the resistance element Rh _n and the resistance element Rh _n−1 constituting the series resistance circuit, and the switch 13 _n Is turned on, the potential of the connection portion between the resistance element Rh _n and the resistance element Rh _n−1 is applied to the main wiring W _n .

The series resistance circuit 80 is configured by connecting a plurality of resistance elements Rh _{2 to} Rh _{n + 1} provided corresponding to the main wirings W _{2 to} W _{n + 1} and the switches 13 _{2 to} 13 _{n + 1} in series. One end of the resistor element Rh _{n + 1 that} is one end of the series resistor circuit 80 is connected to a power supply line that generates the potential Vcc, and one end of the resistor element Rh ₂ that is the other end of the series resistor circuit 80 is connected to the reference current source 81. It is connected. A connection portion between the resistance elements of the series resistance circuit 80 and an end portion on the low potential side (reference current source 81 side) of the resistance element Rh ₂ are respectively connected to one ends of the corresponding switches 13 _{2 to} 13 _{n + 1} .

The reference current source 81 is provided between the resistive element Rh ₂ and the ground line. When the reference current source 81 is turned on, the reference current I _ref flows through the resistance elements Rh _{2 to} Rh _{n + 1} of the series resistance circuit 80, and each of the connection portions between the resistance elements of the series resistance circuit 80 and the resistance element Rh ₂ At one end on the low potential side, a potential dropped from the potential Vcc of the power supply line appears.

Offset current source 82 is provided between the end of the high-potential side of the resistor element Rh ₂ (i.e. connecting portion between the resistor Rh ₂ and the resistance element Rh ₃₎ and a ground line. When both the reference current source 81 and the offset current source 82 are turned on, a current obtained by adding the reference current I _ref and the offset current I _offset flows through the resistance elements Rh _{3 to} Rh _{n + 1} of the series resistance circuit 80, and the series resistance A potential further lowered from the potential Vcc of the power supply line appears at each connection portion between the resistance elements of the circuit 80. On the other hand, it does not flow offset current _{I offset} to the resistor element Rh ₂ even when both of the reference current source 81 and the offset current source 82 is turned on, only the reference current _{I ref} flows.

The bypass switch 90 includes a resistance element Rh ₂ that is a connection between the series resistance circuit 80 and the offset current source 82, and an end on the high potential side of the resistance element Rh _{n + 1} that is a connection between the series resistance circuit 80 and the power supply line. Between the end portion on the high potential side. By the bypass switch 90 is turned on, the potential Vcc of the power supply line is applied to the end portion of the high-potential side of the resistor element Rh _2.

The battery cell selection switch group 20 includes a first battery cell selection switch group 21 and a second battery cell selection switch group 22. The first battery cell selection switch group 21 and the second battery cell selection switch group 22 each include a plurality of switches 21 _{1 to} 21 _{n + 1} provided corresponding to the main wirings W _{1 to} W _{n + 1} , respectively. A plurality of switches 22 _{1 to} 22 _{n + 1} are included.

Each of the plurality of switches 21 _{1 to} 21 _{n + 1} constituting the first battery cell selection switch group 21 has one end connected to the corresponding main wiring and the other end connected to the first node n ₁ . For example, the switch 21 _n has one end connected to the main wiring W _n and the other end connected to the first node n _{1. When} the switch 21 _n is turned on, the potential of the main wiring W _n is changed to the first level. Applied to _one node n ₁ . Each of the plurality of switches 22 _{1 to} 22 _{n + 1} constituting the second battery cell selection switch group 22 has one end connected to the corresponding main wiring and the other end connected to the second node n ₂ . For example, the switch 22 _n-1 has one end connected to the main wiring W _n-1 and the other end connected to the second node n _{2. When} the switch 22 _n-1 is turned on, the main wiring A potential of W _n−1 is applied to the second node n ₂ . Between the second node n ₂ and the ground line, the switch 64 is provided. When the switch 64 is turned on, the second node n ₂ ground potential is applied.

The level shifter 30 includes a first node n ₁ and the potential difference between the second node n _2, and outputs the converted voltage referenced to ground potential. The voltage output from the level shifter 30 is supplied to the AD converter 70. The AD converter 70 outputs a digital value indicating the magnitude of the input voltage.

The reference power supply 40 outputs a reference voltage V _S. Reference voltage V _S is supplied to the voltage dividing circuit 50 is supplied to the power supply wire W _H on the high potential side by the switch 61 is turned on.

Voltage dividing circuit 50 includes a plurality of resistance elements R connected in series, one end connected to each of the connecting portions between the resistor elements, the other end of which is connected to the output line W _d of the divided voltage V _D A plurality of switches 51 are included. A switch 63 is provided between one end of the resistance element R and the ground line. The other end of the resistance element R is connected to the output line of the reference power supply 40. In the voltage dividing circuit 50, when the switch 63 is turned on and any one of the plurality of switches 51 is turned on, the divided voltage V _{D obtained} by dividing the reference voltage V _S is supplied to the output line W _d . Output. The magnitude of the divided voltage V _D output from the output line W _d can be changed by switching a switch to be turned on among the plurality of switches 51. For example, the switch 51 may be switched so that a specific divided voltage V _D is applied to the main wiring selected as the diagnosis target. Divided voltage V _D is supplied to the power supply line W _L on the low potential side by the switch 62 is turned on.

  Battery cell connection switch group 11, power supply connection switch 12, power supply connection switch group 13 bypass switch 90, switches constituting battery cell selection switch group 20, switches 51, 61 to 64, reference current source 81 and offset The current source 82 is turned on / off based on a control signal supplied from the control unit 110.

Hereinafter, the operation of the semiconductor device 100 will be described. First, the operation when measuring cell voltages of a battery cell, a case of measuring the cell voltages of the battery cells C _n as an example.

When measuring the cell voltage of the battery cell, each switch constituting the power connection switch 12 and the power connection switch group 13 and the switches 61 to 64 are turned off. On the other hand, when measuring the cell voltage of the battery cell C _n , the switches 11 _n-1 and 11 _n among the switches constituting the battery cell connection switch group 11 are turned on. Thus, the main wiring W _n potential of an anode of the battery cell C _n is applied to the cathode potential of the main wiring W _n-1 to the cell C _n is applied. Further, the switch 21 _n of the switches constituting the first battery cell selection switch group 21 is turned on, and the switch 22 _n of the switches constituting the second battery cell selection switch group 22 is turned on. _-1 is turned on. Accordingly, the potential of the anode of the battery cell C _n applied to the main wiring W _n is applied to the first node n ₁ and the cathode of the battery cell C _n applied to the main wiring W _n−1. potential of is applied to the second node n _2.

The level shifter 30, the potential difference between the first node n ₁ and the second node n _2, i.e., outputs a voltage corresponding to the cell voltage of the battery cell C _n. The voltage output from the level shifter 30 is supplied to the AD converter 70. The AD converter 70 outputs a digital value corresponding to the cell voltage of the battery cell C _n supplied from the level shifter 30, and supplies this to the control unit 110. Control unit 110 stores a digital value corresponding to the cell voltages of the battery cells C _n received from the AD converter 70 in the storage unit 120.

Next, an operation when performing self-diagnosis for detecting an abnormality of the inspection circuit 10 in the semiconductor device 100 will be described. FIG. 3 is a flowchart showing a flow of operation when performing self-diagnosis of the semiconductor device 100. In the self-diagnosis according to the present embodiment, the main wirings W ₂ and W ₃ among the plurality of main wirings W _{1 to} W _{n + 1} are to be diagnosed.

  In step S1, the control unit 110 forms the first state shown in FIG.

In the first state, the switches constituting the battery cell connection switch group 11, the bypass switch 90, and the switches 61, 63, 64 are turned off, and the switches and switch 62 constituting the power supply switch group 13 are turned on. State. In the first state, the reference current source 81 is turned on and the offset current source 82 is turned off. Thus, the reference current _{I ref} flows through the resistance element _Rh 2 _{~Rh n + 1} of the series resistor circuit 80, the potential of the end on the high potential side of the resistor element Rh ₂ is applied to the main wire _{W 3} is a diagnosis target, resistance The potential at the end on the low potential side of the element Rh ₂ is applied to the main wiring W ₂ that is the object of diagnosis. That is, a diagnostic voltage corresponding to I _ref × Rh ₂ is applied between the main wiring W ₃ and the main wiring W ₂ . In the first state, the main wiring W ₃ has a potential dropped from the potential Vcc of the power supply line, that is, a potential corresponding to Vcc− (Rh _{n + 1} + Rh _n + Rh _n−1 +... + Rh ₃ ) × I _ref. Applied.

Further, in the first state, the first battery cell selection switch group 21, the switch 21 ₃ corresponding to the main wiring W ₃ to be diagnosed is turned on, the other switches are turned off . Thus, the main wiring _{W 3} is connected to the first node _{n 1.} Further, in the first state, the second battery cell selection switch group 22, the switch 22 ₂ corresponding to the main wiring W ₂ to be diagnosed is turned on, the other switches are turned off . Thus, the main wiring _{W 2} is connected to the second node _{n 2.}

The level shifter 30 in step S2 to output a voltage corresponding to a potential difference between the first node n ₁ and the second node n _2. That is, the level shifter 30 outputs a voltage corresponding to the difference between the applied potential and is applied to the main wiring W ₃ potential to the main wiring W _2. When there is no abnormality in the inspection circuit 10, the level shifter 30 outputs a voltage substantially equal to the diagnostic voltage (I _ref × Rh ₂ ).

  In step S <b> 3, the AD converter 70 outputs a digital value A corresponding to the output voltage of the level shifter 30, and supplies this to the control unit 110.

  In step S <b> 4, the control unit 110 stores the digital value A output from the AD converter 70 in the storage unit 120.

  In step S5, the control unit 110 forms the second state shown in FIG.

The second state is different from the first state in that the offset current source 82 is turned on, and the other points are the same as the first state. In the second state, since both the reference current source 81 and the offset current source 82 are turned on, the reference current I _ref and the offset current I _offset are applied to the resistance elements Rh _{3 to} Rh _{n + 1} of the series resistance circuit 80. The total current flows. Therefore, in the second state, the main wiring W ₃ has a potential further lowered from the potential Vcc of the power supply line, that is, Vcc− (Rh _{n + 1} + Rh _n + Rh _n−1 +... + Rh ₃ ) × (I _ref + I A potential corresponding to _offset ) is applied. That is, the potential applied to the main wiring W ₃ in the second state decreases compared to the first state. On the other hand, it does not flow offset current _{I offset} to the resistor element Rh _2, only the reference current _{I ref} flows. Therefore, in the second state, a diagnostic voltage corresponding to I _ref × Rh ₂ is applied between the main wiring W ₃ and the main wiring W _{2 as} in the first state. Therefore, the potential applied to the main wiring W2 in the _second state is smaller than that in the first state. In the second state, similar to the first state, the main wire W ₃ is connected to the first node n _1, the main wiring W ₂ is connected to the second node n _2.

The level shifter 30 in step S6 to output a potential difference voltage corresponding to between the first node n ₁ and the second node n _2. That is, the level shifter 30 outputs a voltage corresponding to the difference of the voltage applied voltage applied to the main wiring W ₃ and the main wiring W _2. When there is no abnormality in the inspection circuit 10, the level shifter 30 outputs a voltage substantially equal to the diagnostic voltage (I _ref × Rh ₂ ).

  In step S 7, the AD converter 70 outputs a digital value B corresponding to the output voltage of the level shifter 30, and supplies this to the control unit 110.

  In step S <b> 8, the control unit 110 stores the digital value B output from the AD converter 70 in the storage unit 120.

  In step S9, the control unit 110 forms the third state shown in FIG.

The third state is different from the first state in that the bypass switch 90 is turned on, and is otherwise the same as the first state. In the third state, the offset current source 82 is turned off. In the third state, that the bypass switch 90 is turned on, the main wiring W _3, the potential Vcc of the power supply line is applied. That is, the potential applied to the main wiring W ₃ in the _third state is larger than that in the first state. On the other hand, in the third state, it flows the reference current _{I ref} to the resistor element Rh _2. Therefore, in the third state, a diagnostic voltage corresponding to I _ref × Rh ₂ is applied between the main wiring W ₃ and the main wiring W _{2 as} in the first state and the second state. Accordingly, the potential applied to the main wiring W ₂ in the third state becomes larger than the first state. In the third state, as in the first state and the second state, the main wiring W ₃ is connected to the first node n ₁ and the main wiring W ₂ is connected to the second node n ₂ .

The level shifter 30 in step S10 outputs the difference voltage corresponding to between the first node n ₁ and the second node n _2. That is, the level shifter 30 outputs a voltage corresponding to the difference of the voltage applied voltage applied to the main wiring W ₃ and the main wiring W _2. When there is no abnormality in the inspection circuit 10, the level shifter 30 outputs a voltage substantially equal to the diagnostic voltage (I _ref × Rh ₂ ).

  In step S <b> 11, the AD converter 70 outputs a digital value C corresponding to the output voltage of the level shifter 30, and supplies this to the control unit 110.

  In step S <b> 12, the control unit 110 stores the digital value C output from the AD converter 70 in the storage unit 120.

  In step S13, the control unit 110 reads the digital values A, B, and C stored in the storage unit 120, and each of the digital values A, B, C is within a predetermined range and the digital values A, B, C It is determined whether or not the difference between each other is within a predetermined range. If the controller 110 determines that each of the digital values A, B, and C is within the predetermined range and the difference between the digital values A, B, and C is within the predetermined range, the process proceeds to step S14. Otherwise, the process proceeds to step S15.

In step S <b> 14, the control unit 110 determines that there is no abnormality in the inspection circuit 10. On the other hand, in step S15, the control unit 110 determines that the inspection circuit 10 has an abnormality. That is, when there is no abnormality in the inspection circuit 10, the digital values A, B, C, respectively, to the main wiring _{W 3} and applied diagnosed voltage between the main wire _{W 2 (I ref × Rh 2} ) The corresponding value. Therefore, it is possible to detect the presence or absence of abnormality of the inspection circuit 10 by determining whether the digital values A, B, and C are within a range of ± 5% of the diagnostic voltage (I _ref × Rh ₂ ), for example. Is possible. Further, with respect to the abnormality that manifested in the case of changing the potential applied respectively to the main wiring W ₃ and main wiring W _2, or digital values A, B, the difference between the C cross is within a predetermined range not It is possible to detect by determining.

In step S16, the control unit 110 outputs the determination result in step S14 or step S15 from the output terminal _TOUT .

  As described above, according to the semiconductor device 100 and the battery monitoring 1 system according to the present embodiment, the potential applied to each of the main wirings while keeping the diagnostic voltage applied between the pair of main wirings to be diagnosed constant. It is possible to monitor the fluctuation of the voltage generated between the main wirings when the voltage is increased or decreased. Therefore, it becomes possible to detect an abnormality that becomes apparent when the potential applied to the main wiring to be diagnosed is changed.

In the present embodiment, the main wire W ₃ and is the main wire W ₂ exemplified a case where the diagnosis target may be diagnosed the main wiring other than the above.

Further, in the present embodiment, the case where the voltage generated at both ends of the resistance element Rh ₂ among the plurality of resistance elements constituting the series resistance circuit 80 is used as the diagnostic voltage is exemplified. A voltage generated between both ends of the resistance element may be used as a diagnostic voltage.

Further, in the present embodiment, the configuration in which the offset current source 82 is connected to the end on the high potential side of the resistance element Rh ₂ that generates the diagnostic voltage is illustrated, but the high potential of the resistance element that generates the diagnostic voltage of the series resistance circuit 80 is illustrated. The offset current source 82 may be connected to a connection portion between resistance elements having a higher potential than the end portion on the side.

Further, although the illustrated configuration in which the bypass switch 90 between a high-potential end of the resistive element Rh ₂ resulting diagnostic voltage as the power supply line in this embodiment, the bypass switch 90, the resistance element to produce a diagnostic voltage It may be provided between the connection portion between the resistance elements having a higher potential than the end portion on the high potential side of Rh ₂ and the end portion on the high potential side of the resistance element that generates the diagnostic voltage.

  Moreover, in this embodiment, although the case where the fluctuation | variation of the voltage between main wiring at the time of forming three states in the test | inspection circuit 10 was illustrated, any 2 of said 1st-3rd states was illustrated. You may monitor the fluctuation | variation of the voltage between main wirings at the time of forming one state.

[Second Embodiment]
FIG. 7 is a diagram showing a configuration of an inspection circuit 10A according to the second embodiment of the present invention. The inspection circuit 10A includes a plurality of switches 91 ₃ , 91 ₄ ,... That play a role of the bypass switch 90 (see FIG. 2) and a connection destination of the offset current source 82 in the inspection circuit 10 according to the first embodiment. A switch group 91 including 91 _n−1 , 91 _n , 91 _{n + 1} , 91 _{n + 2} is included. One end of each of the switches 91 ₃ , 91 ₄ ,..., 91 _n−1 , 91 _n , 91 _{n + 1} is connected to a connection portion between the resistance elements of the series resistance circuit 80, and the other end is connected to the offset current source 82. It is connected to the node n ₃ being. For example, the switch 91 _n has one end connected to a connection portion between the resistance element Rh _n and the resistance element Rh _n−1 and the other end connected to the node n ₃ . When the switch 91 _n is turned on, the connection between the resistance element Rh _n and the resistance element Rh _n−1 is connected to the offset current source 82. On the other hand, the switch 91 n _{+ 2} has one end connected to a power supply line resulting in potential Vcc, the other end is connected to the node n _3. For example, a switch _{91 n + 2} and the switch 91 ₃ By the ON state, the connection portion between the resistor Rh ₃ and the resistance element Rh _2, potential Vcc is applied.

Self-diagnosis for detecting an abnormality of the test circuit 10A, as in the first embodiment, the main wire W ₂ and W ₃ are diagnosed, are performed in the procedure shown in the flow chart shown in FIG.

  FIG. 8 is a diagram showing a first state formed in the inspection circuit 10A when the process of step S1 of the flowchart shown in FIG. 3 is performed.

In the first state, all the switches constituting the switch group 91 are turned off. The other states are the same as the first state (see FIG. 4) in the inspection circuit 10 according to the first embodiment. That is, in the first state, the switches constituting the battery cell connection switch group 11, the switches 61, 63, 64 are turned off, and the switches constituting the power supply connection switch group 13 and the switch 62 are turned on. Is done. In the first state, the reference current source 81 is turned on and the offset current source 82 is turned off. Thus, the reference current _{I ref} flows through the resistance element _Rh 2 _{~Rh n + 1} of the series resistor circuit 80, the potential of the end on the high potential side of the resistor element Rh ₂ is applied to the main wire _{W 3} is a diagnosis target, resistance The potential at the end on the low potential side of the element Rh ₂ is applied to the main wiring W ₂ that is the object of diagnosis. That is, a diagnostic voltage corresponding to I _ref × Rh ₂ is applied between the main wiring W ₃ and the main wiring W ₂ . In the first state, the main wiring W ₃ has a potential dropped from the potential Vcc of the power supply line, that is, a potential corresponding to Vcc− (Rh _{n + 1} + Rh _n + Rh _n−1 +... + Rh ₃ ) × I _ref. Applied. In the first state, the main wiring W ₃ is connected to the first node n ₁ , and the main wiring W ₂ is connected to the second node n ₂ .

  FIG. 9 is a diagram illustrating an example of a second state formed in the inspection circuit 10A when the process of step S5 in the flowchart illustrated in FIG. 3 is performed.

In a second state, of the switches constituting the switch group 91, for example, only the switch 91 ₃ is turned on, the other switches are turned off. In the second state, the states of the switches other than the switches constituting the switch group 91 are the same as the first state. On the other hand, in the second state, the offset current source 82 is turned on. As a result, a current obtained by adding the reference current I _ref and the offset current I _offset flows through the resistance elements Rh _{3 to} Rh _{n + 1} of the series resistance circuit 80. Therefore, in the second state, the main wiring W ₃ has a potential further lowered from the potential Vcc of the power supply line, that is, Vcc− (Rh _{n + 1} + Rh _n + Rh _n−1 +... + Rh ₃ ) × (I _ref + I A potential corresponding to _offset ) is applied. That is, the potential applied to the main wiring W ₃ in the second state is smaller than that in the first state. On the other hand, it does not flow offset current _{I offset} to the resistor element Rh _2, only the reference current _{I ref} flows. Therefore, in the second state, a diagnostic voltage corresponding to I _ref × Rh ₂ is applied between the main wiring W ₃ and the main wiring W _{2 as} in the first state. Therefore, the potential applied to the main wiring W2 in the _second state is smaller than that in the first state. In the second state, similar to the first state, the main wire W ₃ is connected to the first node n _1, the main wiring W ₂ is connected to the second node n _2.

According to the inspection circuit 10A according to the present embodiment, by switching the switch to the ON state among the switches constituting the switch group 91, changing the potential applied to the main wiring W ₃ and main wire W ₂ Can do. For example, when the switch 91 ₃ to the ON state as shown in FIG 9, the potential applied to the main wire _{W 3} being minimized and its _{size, Vcc- (Rh n + 1 +} Rh n + Rh n-1 + · ·· + Rh ₃ ) × (I _ref + I _offset ). On the other hand, when the switch 91 _{n + 1} is turned on, the voltage applied to the main wiring W ₃ becomes maximum, and the magnitude thereof is Vcc−Rh _{n + 1} × (I _ref + I _offset ) − (Rh _n + Rh _n−1 + ... + Rh ₃ ) × I _ref . According to the inspection circuit 10A according to the present embodiment, the main wiring in the range from the minimum value to the maximum value can be obtained by switching the switch that is turned on among the switches configuring the switch group 91 in the second state. the potential applied to W ₃ can be stepwise changed. On the other hand, even if the changeover switch to the ON state among the switches constituting the switch group 91, and the state in which the resistance element Rh ₂ caused a diagnosis voltage flows a reference current I _ref is maintained, a main wire W ₃ The magnitude of the diagnostic voltage applied between the main wiring W ₂ is kept constant (I _ref × Rh ₂ ). The potential applied to the main wire W ₂ changes according to the change of the potential applied to the main wiring W _3.

  FIG. 10 is a diagram illustrating an example of a third state formed in the inspection circuit 10A when the process of step S9 in the flowchart illustrated in FIG. 3 is performed.

In a third state, among the switches constituting the switch group 91, for example, switch 91 ₃ and 91 n _{+ 2} is turned on, the other switches are turned off. In the third state, the states of the switches other than the switches constituting the switch group 91 are the same as the first state. In the third state, the offset current source 82 is turned off.

In the third state, when the switch 91 ₃ and _{91 n + 2} is turned on, the main wiring _{W 3,} the potential Vcc of the power supply line is applied. That is, the potential applied to the main wiring W ₃ in the _third state is larger than that in the first state. On the other hand, in the third state flows the reference current _{I ref} to the resistor element Rh _2. Therefore, in the third state, a diagnostic voltage corresponding to I _ref × Rh ₂ is applied between the main wiring W ₃ and the main wiring W _{2 as} in the first state and the second state. Accordingly, the potential applied to the main wiring W ₂ in the third state becomes larger than the first state. In the third state, as in the first state and the second state, the main wiring W ₃ is connected to the first node n ₁ and the main wiring W ₂ is connected to the second node n ₂ .

According to the inspection circuit 10A according to the present embodiment, by switching the combination of the two switches to be turned on among the switches constituting the switch group 91, the potential applied to the main wiring W ₃ and main wire W ₂ Can be changed. For example, when the switch 91 ₃ and 91 n _{+ 2} in the ON state as shown in FIG. 10, the voltage becomes maximum is applied to the main wiring W _3, its size is Vcc. Meanwhile, the voltage applied to the main wiring _{W 3} when the switch 91 ₃ and 91 ₄ in the ON state is minimal, its _{size, Vcc- (Rh n + 1 +} Rh n + Rh n-1 + ··· + Rh 4 ) × I _ref . According to the inspection circuit 10A according to the present embodiment, the range from the minimum value to the maximum value can be obtained by switching the combination of two switches that are turned on among the switches constituting the switch group 91 in the third state. it is possible to stepwise change the level of the in the voltage applied to the main wiring W _3. On the other hand, even if the changeover switch to the ON state of the switches constituting the switch group 91, and the state in which the resistance element Rh ₂ caused a diagnosis voltage flows a reference current I _ref is maintained, the main wiring W ₃ main The magnitude of the diagnostic voltage applied between the wiring W ₂ is kept constant (I _ref × Rh ₂ ). The potential applied to the main wire W ₂ changes according to the change of the potential applied to the main wiring W _3.

  As described above, according to the inspection circuit 10A according to the present embodiment, in the second state and the third state, the switch to be turned on among the switches configuring the switch group 91 is switched, so that the diagnosis target The potential applied to each main wiring can be changed while maintaining the diagnosis voltage applied between the pair of main wirings constant. Therefore, the change width of the potential applied to each main wiring can be made smaller than that of the inspection circuit 10 according to the first embodiment, and the accuracy of self-diagnosis can be further increased.

[Third Embodiment]
FIG. 11 is a diagram showing a configuration of an inspection circuit 10B according to the third embodiment of the present invention. In the inspection circuit 10 </ b> B, the output of the level shifter 30 is connected to the AD converter 70 via the switch 65. Further, the output line W _d of the divided voltage V _D is connected to the AD converter 70 via the switch 66. Further, the output line of the reference power supply 40 is connected to the AD converter 70. In the inspection circuit 10B according to the present embodiment, when the output voltage of the level shifter 30 is converted into a digital value by the AD converter 70, the switch 65 is turned on.

  According to the test circuit 10B according to the present embodiment, the same effect as that of the test circuit 10 according to the first embodiment can be obtained. Note that the switch group 91 of the inspection circuit 10A according to the second embodiment can be applied to the inspection circuit 10B according to the present embodiment.

  In each of the above embodiments, the case where the inspection circuit 10 (10A, 10B), the control unit 110, and the storage unit 120 are formed on a single semiconductor chip is illustrated. However, for example, as shown in FIG. The system includes a first semiconductor chip 100A including the inspection circuit 10 (10A and 10B), and a second semiconductor chip 100B separate from the first semiconductor chip 100A including the control unit 110 and the storage unit 120. And the assembled battery 200 including a plurality of battery cells.

In addition, the battery cell selection switch group 20 of the inspection circuit 10 (10A, 10B) of each of the embodiments described above is provided corresponding to each of the plurality of main wirings W _{1 to} W _{n + 1} and has one end corresponding to the main wiring. Each of the first battery cell selection switch group 21 including the plurality of switches 21 _{1 to} 21 _{n + 1} and the other main wirings W _{1 to} W _{n + 1} connected to the first node n _1. And a second battery cell selection switch group 22 including a plurality of switches 22 _{1 to} 22 _{n + 1} having _one end connected to the corresponding main wiring and the other end connected to the second node n _2. It was comprised including. The battery cell selection switch group 20 can be replaced with a battery cell selection switch group 20A having the configuration shown in FIG.

The battery cell selection switch group 20A includes a plurality of switches 23 ₁ to 23 _{n + 1} provided corresponding to each of the plurality of main wirings W _{1 to} W _{n + 1} . Each of the switches 23 ₁ to 23 _{n + 1} is a three-contact switch having contacts a, b, and c. The contact a is connected to the corresponding main wiring, the contact b is connected to the first node n ₁ , and the contact c is It is connected to the second node n _2. The plurality of switches 23 ₁ to 23 _{n + 1} are connected to either the contact b or the contact c and the contact a is connected to either the contact b or the contact c based on the control from the control unit 110. It is possible to switch to any of the states that have not been done.

In the inspection circuit 10 (10A, 10B), even when the battery cell selection switch group 20A is applied, the same effect as when the battery cell selection switch group 20 is applied can be obtained. That is, the battery cell selection switch group has any configuration as long as it switches connection and non-connection to the first node n ₁ or the second node n ₂ of each of the plurality of main wirings W _{1 to} W _{n + 1.} You may have.

DESCRIPTION OF SYMBOLS 1 Battery monitoring system 10, 10A, 10B Inspection circuit 11 Switch group for battery cell connection 12 Switch for power supply connection 13 Switch group for power supply connection 20 Switch group for battery cell selection 21 First switch group for battery cell selection 22 First Battery cell selection switch group 30 Level shifter 40 Reference power supply 50 Voltage divider circuit 70 AD converter 80 Series resistance circuit 81 Reference current source 82 Offset current source 90 Bypass switch 91 Switch group 100 Semiconductor device 110 Control unit 120 Storage unit C _{2 to} C _{n + 1} Battery cells W _{1 to} W _{n + 1} main wiring n ₁ first node n ₂ second node

Claims (14)

A plurality of main wirings provided corresponding to each of the nodes generating different potentials of the plurality of battery cells connected in series;
A series resistor circuit including a plurality of resistor elements connected in series, one end of which is connected to the power supply line;
A first current source connected to the other end of the series resistor circuit;
An end portion on the high potential side of a specific resistance element among the plurality of resistance elements, or a connection portion between resistance elements having a higher potential than an end portion on the high potential side of the specific resistance element in the series resistance circuit A second current source connected to
A first switch provided between one of a pair of diagnosis target wires of the plurality of main wires and one end of the specific resistance element;
A second switch provided between the other of the pair of diagnosis target wires and the other end of the specific resistance element;
A semiconductor device including: And further comprising a bypass switch provided between a portion of the series resistance circuit having a higher potential than an end portion on the high potential side of the specific resistance element and an end portion on the high potential side of the specific resistance element. Item 14. The semiconductor device according to Item 1. A switch group including a plurality of switches for switching connection and non-connection to the first node or the second node of each of the plurality of main wirings;
A voltage output unit that outputs a voltage corresponding to a difference between the potential of the first node and the potential of the second node;
The semiconductor device according to claim 2. The first switch and the second switch are in an on state, the bypass switch is in an off state, the first current source is in an on state, and the second current source is in an off state. The switch group is controlled so that one is connected to the first node and the other of the pair of diagnosis target wirings is connected to the second node, and the potential of the first node from the voltage output unit A first state for outputting a voltage corresponding to a difference from the potential of the second node;
While the first switch and the second switch are turned on, the bypass switch is turned off, the first current source is turned on, and the second current source is turned on, the pair of diagnosis target wires The switch group is controlled so that one is connected to the first node and the other of the pair of diagnosis target wirings is connected to the second node, and the potential of the first node from the voltage output unit A second state in which a voltage corresponding to a difference from the potential of the second node is output;
The semiconductor device according to claim 3, further comprising a control unit that sequentially forms the first and second layers. The control unit is configured to turn on the first switch and the second switch, turn on the bypass switch, turn on the first current source, and turn off the second current source. The switch group is controlled so that one of the diagnosis target wirings is connected to the first node, and the other of the pair of diagnosis target wirings is connected to the second node, and the first output from the voltage output unit. The semiconductor device according to claim 4, further forming a third state in which a voltage corresponding to a difference between the potential of the node and the potential of the second node is output. A plurality of main wirings provided corresponding to each of the nodes generating different potentials of the plurality of battery cells connected in series;
A series resistor circuit including a plurality of resistor elements connected in series, one end of which is connected to the power supply line;
A first current source connected to the other end of the series resistor circuit;
An end portion on the high potential side of a specific resistance element among the plurality of resistance elements, or a connection portion between resistance elements having a higher potential than an end portion on the high potential side of the specific resistance element in the series resistance circuit A second current source selectively connected to any of the
A first switch provided between one of a pair of diagnosis target wires of the plurality of main wires and one end of the specific resistance element;
A second switch provided between the other of the pair of diagnosis target wires and the other end of the specific resistance element;
A semiconductor device including: A first switch group including a plurality of switches each having one end connected to a connection portion between adjacent resistance elements of the series resistor circuit and each other end connected to the second current source. Item 7. The semiconductor device according to Item 6. The semiconductor device according to claim 7, wherein the first switch group further includes a switch having one end connected to the power supply line and the other end connected to the second current source. A second switch group including a plurality of switches for switching connection and non-connection to the first node or the second node of each of the plurality of main wirings;
A voltage output unit that outputs a voltage corresponding to a difference between the potential of the first node and the potential of the second node;
The semiconductor device according to claim 8, further comprising: The first switch and the second switch are turned on, each of the plurality of switches constituting the first switch group is turned off, the first current source is turned on, and the second current source is turned on The second switch group is controlled so that one of the pair of diagnosis target wirings is connected to the first node and the other of the pair of diagnosis target wirings is connected to the second node while being turned off. A first state in which a voltage corresponding to a difference between the potential of the first node and the potential of the second node is output from the voltage output unit;
Turning on the first switch and the second switch; turning on one of a plurality of switches constituting the first switch group; turning on the first current source; The second switch group is configured such that one of the pair of diagnosis target wires is connected to the first node and the other of the pair of diagnosis target wires is connected to the second node while a current source is turned on. A second state in which the voltage output unit outputs a voltage corresponding to the difference between the potential of the first node and the potential of the second node from the voltage output unit,
The semiconductor device according to claim 9, further comprising: a control unit that sequentially forms. The control unit turns on the first switch and the second switch, turns on any two of a plurality of switches constituting the first switch group, and turns on the first current source. The one of the pair of diagnosis target wirings is connected to the first node while the second current source is turned off, and the other of the pair of diagnosis target wirings is connected to the second node. 11. A third state is further formed in which a second switch group is controlled to output a voltage corresponding to a difference between the potential of the first node and the potential of the second node from the voltage output unit. A semiconductor device according to 1. A plurality of battery cells connected in series;
A plurality of main wirings provided corresponding to each of the nodes generating different potentials of the battery cells;
A series resistor circuit including a plurality of resistor elements connected in series, one end of which is connected to the power supply line;
A first current source connected to the other end of the series resistor circuit;
An end portion on the high potential side of a specific resistance element among the plurality of resistance elements, or a connection portion between resistance elements having a higher potential than an end portion on the high potential side of the specific resistance element in the series resistance circuit A second current source connected to
A first switch provided between one of a pair of diagnosis target wires of the plurality of main wires and one end of the specific resistance element;
A second switch provided between the other of the pair of diagnosis target wires and the other end of the specific resistance element;
A switch group including a plurality of switches for switching connection and non-connection to the first node or the second node of each of the plurality of main wirings;
A voltage output unit that outputs a voltage corresponding to a difference between the potential of the first node and the potential of the second node;
While the first switch and the second switch are in an on state, the first current source is in an on state, and the second current source is in an off state, one of the pair of diagnosis target wires is connected to the first node. And the switch group is controlled to connect the other of the pair of wirings to be diagnosed to the second node, and the potential of the first node and the potential of the second node are controlled from the voltage output unit. A first state in which a voltage corresponding to the difference between the first switch and the second switch is turned on; the first switch and the second switch are turned on; the first current source is turned on; and the second current source is turned on The voltage output unit is configured to control the switch group so that one of the pair of diagnosis target wirings is connected to the first node and the other of the pair of diagnosis target wirings is connected to the second node. To the potential of the first node And a second state to output a voltage corresponding to the difference between the potential of the second node, and sequentially forming control unit,
Including battery monitoring system. A plurality of main wirings provided corresponding to each of the nodes generating different potentials of the plurality of battery cells connected in series;
A series resistor circuit including a plurality of resistor elements connected in series, one end of which is connected to the power supply line;
A first current source connected to the other end of the series resistor circuit;
An end portion on the high potential side of a specific resistance element among the plurality of resistance elements, or a connection portion between resistance elements having a higher potential than an end portion on the high potential side of the specific resistance element in the series resistance circuit A second current source selectively connected to any of the
A first switch provided between one of a pair of diagnosis target wires of the plurality of main wires and one end of the specific resistance element;
A second switch provided between the other of the pair of diagnosis target wires and the other end of the specific resistance element;
A first switch group including a plurality of switches each having one end connected to a connection portion between adjacent resistance elements of the series resistor circuit and each other end connected to the second current source;
A second switch group including a plurality of switches for switching connection and non-connection to the first node or the second node of each of the plurality of main wirings;
A voltage output unit that outputs a voltage corresponding to a difference between the potential of the first node and the potential of the second node;
The first switch and the second switch are turned on, each of the plurality of switches constituting the first switch group is turned off, the first current source is turned on, and the second current source is turned on The second switch group is controlled so that one of the pair of diagnosis target wirings is connected to the first node and the other of the pair of diagnosis target wirings is connected to the second node while being turned off. A first state in which a voltage corresponding to a difference between the potential of the first node and the potential of the second node is output from the voltage output unit;
Turning on the first switch and the second switch; turning on one of a plurality of switches constituting the first switch group; turning on the first current source; The second switch group is configured such that one of the pair of diagnosis target wires is connected to the first node and the other of the pair of diagnosis target wires is connected to the second node while a current source is turned on. A second state in which the voltage output unit outputs a voltage corresponding to the difference between the potential of the first node and the potential of the second node from the voltage output unit,
A control unit for sequentially forming
Including battery monitoring system. A series resistor having a plurality of main wires provided corresponding to respective nodes that generate different potentials of a plurality of battery cells connected in series, and a plurality of resistance elements connected in series and one end connected to a power supply line A method of diagnosing a semiconductor device including a circuit,
A voltage generated at both ends of a specific resistance element of the plurality of resistance elements by applying a current to the series resistance circuit is applied between a pair of diagnosis target wirings of the plurality of main wirings, and the pair Measuring a voltage between wirings to be diagnosed,
The voltage generated at both ends of the specific resistance element is applied between the pair of diagnosis target wires by changing the potential at one end of the specific resistance element while maintaining the magnitude of the current flowing through the specific resistance element. Measuring a voltage between the pair of wirings to be diagnosed;
A diagnostic method comprising:

Images