Battery monitoring device

Abstract

To suppress a measurement error of a cell voltage caused by an operation current of a cell selection switch.SOLUTION: A battery monitoring device includes an analog / digital converter, and a first cell selection switch that selectively connects any of a plurality of battery cells with the analog / digital converter. The first cell selection switch includes: a first switch part that is provided on a conductive path extending from one of the plurality of battery cells to the analog / digital converter, brings the conductive path into a conductive state in an on-state, and brings the conductive path into a non-conductive state in an off-state; and a first switching part that switches on and off of the first switch part, and has a first bias part that, when the first switch part is in the on-state, supplies a current flowing in the first cell selection switch from a path different from the conductive path.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The disclosed technology relates to a battery monitoring device.

Background Art

[0002] Regarding the technology for measuring the voltage of each battery cell of a battery pack configured to include a plurality of battery cells connected in series, the following technologies are known. For example, Patent Document 1 describes a battery monitoring device that monitors a cell group in which a plurality of single battery cells are connected in series, the battery monitoring device including a reference voltage generation circuit that generates a variable reference voltage, a switching circuit that selects any one of a plurality of types of voltages including the cell voltage and the reference voltage of each single battery cell of the cell group as a measurement target voltage, and an AD converter that measures the measurement target voltage selected by the switching circuit and outputs a digital signal according to the measurement result.

[0003] Patent Document 2 describes a battery system including a selection circuit that selects and outputs the terminal voltage of a battery cell to be measured from the input terminal voltage, an AD converter that performs analog-digital conversion on the terminal voltage selected by the selection circuit, a selection signal generation circuit that outputs a selection signal to the selection circuit to cause the selection circuit to select the terminal voltage of the battery cell to be measured so that the selection operation of the selection circuit is executed, and a diagnosis circuit that diagnoses whether the selection signal output from the selection signal generation circuit is correct.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] A battery monitoring device that monitors the state of battery cells of a battery pack configured to include a plurality of battery cells connected in series has a function of measuring the terminal voltage (hereinafter referred to as cell voltage) of each of the plurality of battery cells. To realize this function, the battery monitoring device includes an analog-to-digital converter and a plurality of cell selection switches that selectively connect any one of the plurality of battery cells to the analog-to-digital converter. A low-pass filter including a resistor element and a capacitor is connected between the battery monitoring device and each battery cell to remove noise mixed in during cell voltage measurement. When measuring the cell voltage, an operating current flows through the cell selection switch. The operating current of the cell selection switch also flows through the resistor element that constitutes the low-pass filter, causing a voltage drop in the resistor element, resulting in an error that cannot be ignored in the measured value of the cell voltage. For example, when the resistance value of the resistor element that constitutes the low-pass filter is 1 kΩ and the operating current of the cell selection switch is 1 μA, an error of 1 mV is generated in the measured value of the cell voltage. This error is not acceptable in recent in-vehicle battery monitoring devices.

[0006] The disclosed technology has been made in view of the above points, and an object thereof is to suppress a measurement error of the cell voltage caused by the operating current of the cell selection switch.

Means for Solving the Problem

[0007] The battery monitoring device according to the disclosed technology includes an analog-to-digital converter and a first cell selection switch that selectively connects any one of a plurality of battery cells to the analog-to-digital converter. The first cell selection switch is provided on a conductive path from one of the plurality of battery cells to the analog-to-digital converter, and includes a first switch portion that makes the conductive path in a conductive state in the on state and a non-conductive state in the off state, and a first switching portion that switches the on / off of the first switch portion and supplies a current flowing through the first cell selection switch from a path different from the conductive path when the first switch portion is in the on state.

Effect of the Invention

[0008] According to the battery monitoring device related to the disclosed technology, it is possible to suppress the measurement error of the cell voltage caused by the operating current of the cell selection switch.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0010] Hereinafter, embodiments of the disclosed technology will be described with reference to the drawings. In each drawing, substantially the same or equivalent components or parts are given the same reference numerals.

[0011] FIG. 1 is a diagram showing an example of the configuration of a battery monitoring device 10 according to an embodiment of the disclosed technology. The battery monitoring device 10 has a function of measuring the voltage across both ends (hereinafter referred to as the cell voltage) of each battery cell 50 of a battery pack 51 configured to include a plurality of battery cells 50 connected in series. The battery monitoring device 10 is configured by an integrated circuit provided on a semiconductor substrate. The battery monitoring device 10 includes a plurality of cell selection switches 20, a polarity inversion circuit 30, an analog-to-digital converter 40, and a control unit 12. The battery monitoring device 10 has a plurality of connection terminals 11 provided corresponding to each of the battery cells 50. The positive electrode of the corresponding battery cell 50 is connected to each of the connection terminals 11 via a low-pass filter 60.

[0012] A plurality of low-pass filters 60 are provided corresponding to each of the battery cells 50, and each has a resistor element 61 and a capacitor 62. One end of the resistor element 61 is connected to the positive electrode of the corresponding battery cell 50, and the other end is connected to the corresponding connection terminal 11 and one end of the capacitor 62. The other end of the capacitor 62 is connected to the connection terminal 11 corresponding to the battery cell 50 one level lower. Note that the capacitor 62 constituting the low-pass filter 60 corresponding to the lowermost battery cell 50 has one end connected to the corresponding connection terminal 11 and the other end connected to the ground.

[0013] A plurality of cell selection switches 20 are provided corresponding to each of the battery cells 50. The plurality of cell selection switches 20 selectively connect any one of the plurality of battery cells 50 to the analog-digital converter 40. One end of the cell selection switch 20 is connected to the positive electrode of the corresponding battery cell 50 via the connection terminal 11 and the low-pass filter 60, and the other end is connected to the integration node n1 or n2. One of the two adjacent cell selection switches 20 is connected to one of the integration nodes n1 and n2, and the other cell selection switch 20 is connected to the other of the integration nodes n1 and n2.

[0014] The polarity inversion circuit 30 includes four switches 30A, 30B, 30C, and 30D configured including semiconductor elements such as transistors. One end of the switch 30A is connected to the integration node n1, and the other end is connected to the analog input of the analog-digital converter 40. One end of the switch 30B is connected to the integration node n2, and the other end is connected to the analog input of the analog-digital converter 40. One end of the switch 30C is connected to the integration node n2, and the other end is connected to the reference input of the analog-digital converter 40. One end of the switch 30D is connected to the integration node n1, and the other end is connected to the reference input of the analog-digital converter 40. The analog-digital converter 40 outputs a digital value corresponding to the difference between the voltage input to the analog input and the voltage input to the reference input.

[0015] The control unit 12 controls the on / off states of the plurality of cell selection switches 20 and the switches 30A to 30D that constitute the polarity inversion circuit 30. For example, when measuring the cell voltage of the battery cell 50 n , the control unit 12 controls the cell selection switches 20 n and 20 n-1 to be in the on state, the switches 30B and 30D of the polarity inversion circuit 30 to be in the on state, and the switches 30A and 30C of the polarity inversion circuit 30 to be in the off state. As a result, the positive electrode of the battery cell 50 n is connected to the analog input of the analog-to-digital converter 40, and the negative electrode of the battery cell 50 n is connected to the reference input of the analog-to-digital converter 40, and a digital value corresponding to the cell voltage of the battery cell 50 n is output from the analog-to-digital converter 40.

[0016] FIG. 2 is a diagram showing an example of the configuration of the cell selection switch 20 n . Note that the configurations of each of the plurality of cell selection switches 20 are the same as each other. In FIG. 2, the illustration of the polarity inversion circuit 30 is omitted. The cell selection switch 20 n has a switch section 21 and a switching section 22. The switching section 22 has a current mirror circuit 24, switches 73A, 73B, a constant voltage element 25, and a bias section 100. Note that the cell selection switch 20 is an example of the "first cell selection switch" in the disclosed technology. The switch section 21 is an example of the "first switch section" in the disclosed technology. The switching section 22 is an example of the "first switching section" in the disclosed technology. The constant voltage element 25 is an example of the "first constant voltage element" in the disclosed technology. The bias section 100 is an example of the "first bias section" in the disclosed technology.

[0017] The switch section 21 is for the battery cell 50 nIt is provided on the conductive path P1 from the positive electrode to the analog-digital converter 40. The switch unit 21 has two P-channel type MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors) 71A and 71B connected in series. The MOSFETs 71A and 71B are power MOSFETs having a so-called DMOS (Double-diffused MOSFET) configuration. The source of the MOSFET 71A is connected to the positive electrode of the corresponding battery cell 50 via the connection terminal 11 and the resistance element 61 n and the drain is connected to the source of the MOSFET 71B. The drain of the MOSFET 71B is connected to the analog input of the analog-digital converter 40. The gates of the MOSFETs 71A and 71B are respectively connected to the node n3 to which the anode of the Zener diode, which is the constant voltage element 25, is connected.

[0018] When both the MOSFETs 71A and 71B are in the on state, the switch unit 21 is in the on state and the conductive path P1 is in the conductive state. The one-stage lower cell selection switch 20 n-1 is also turned on, so that the positive and negative electrodes of the battery cell 50 n are connected to the analog-digital converter 40, and the digital value corresponding to the cell voltage of the battery cell 50 n is output from the analog-digital converter 40. On the other hand, when both the MOSFETs 71A and 71B are in the off state, the switch unit 21 is in the off state and the conductive path P1 is in the non-conductive state.

[0019] The current mirror circuit 24 has two P-channel MOSFETs 72A and 72B. The sources of MOSFETs 72A and 72B are connected to node n4 which is the connection point of MOSFETs 71A and 71B respectively. The gates of MOSFETs 72A and 72B are connected to the drain of MOSFET 72A respectively. The drain of MOSFET 72A is connected to node n5, and the drain of MOSFET 72B is connected to node n3. The Zener diode which is the constant voltage element 25 has its anode connected to the drain of MOSFET 72B (node n3), and its cathode connected to the source of MOSFE72B (node n4) via the P-channel MOSFET 74. MOSFET 74 has its source connected to node n4, and its gate and drain connected to the cathode of the Zener diode which is the constant voltage element 25.

[0020] One end of switch 73A is connected to node n5, and the other end is connected to current source 26A. One end of switch 73B is connected to node n3, and the other end is connected to current source 26B. Current source 26A draws a constant current with a current value of I1 into the ground line. Current source 26B draws a constant current with a current value of I2 into the ground line. In this embodiment, I1 = I2. It should be noted that I1 ≠ I2 may also be possible.

[0021] The bias unit 100 is a constant current source provided between the battery line VB and the cathode of the constant voltage element 25. When the switch unit 21 is in the on state, the bias unit 100 supplies the operating current flowing through the cell selection switch 20 n from a path different from the conductive path P1.

[0022] The switching unit 22 switches the on / off state of the switch unit 21 by the switches 73A and 73B being complementarily turned on and off according to the control by the control unit 12. When the switch 73A is in the on state and the switch 73B is in the off state, a current with a current value I1 flows through the current mirror circuit 24. As a result, the gate-source voltage between the MOSFETs 71A and 71B constituting the switch unit 21 becomes approximately 0V, and the MOSFETs 71A and 71B are in the off state (that is, the switch unit 21 is in the off state). On the other hand, when the switch 73A is in the off state and the switch 73B is in the on state, the Zener diode, which is the constant voltage element 25, breaks down, and an operating current I with a current value I2 flows through the constant voltage element 25. Z A Zener voltage is generated across the constant voltage element 25. As a result, the gate-source between the MOSFETs 71A and 71B constituting the switch unit 21 is biased by the Zener voltage, and the MOSFETs 71A and 71B are in the on state (that is, the switch unit 21 is in the on state). The operating current I flowing through the constant voltage element 25 Z is supplied from the bias unit 100 connected to the battery line VB. The maximum voltage of the battery pack 51 is applied to the battery line VB. The current flowing from the bias unit 100 toward the node n4 is blocked by the MOSFET 74.

[0023] FIG. 3 is a diagram showing an example of the configuration of the cell selection switch 20X according to the comparative example. The cell selection switch 20X according to the comparative example does not have the bias unit 100 and the MOSFET 74 that the cell selection switch 20 (see FIG. 2) according to the embodiment of the disclosed technology has.

[0024] In the cell selection switch 20X according to the comparative example, when the switch 73A is in the off state and the switch 73B is in the on state, the Zener diode, which is the constant voltage element 25, breaks down, and an operating current I with a current value I2 flows through the constant voltage element 25. Zflows, and a Zener voltage is generated across the constant voltage element 25. As a result, the gate-source voltage of the MOSFETs 71A and 71B that make up the switch section 21 is biased by the Zener voltage, and the MOSFETs 71A and 71B are turned on (i.e., the switch section 21 is turned on). This is the same as the cell selection switch 20 according to the embodiment of the above-described disclosed technology.

[0025] According to the cell selection switch 20X according to the comparative example, the operating current I generated when the switch section 21 is in the on state Z flows through a path passing through the resistance element 61 that constitutes the low-pass filter 60. As a result, a voltage drop occurs in the resistance element 61, so an error that cannot be ignored occurs in the measured value of the cell voltage. When the resistance value of the resistance element 61 is, for example, 1 kΩ and the operating current of the cell selection switch is 1 μA, an error of 1 mV occurs in the measured value of the cell voltage. This error is not allowed in recent in-vehicle battery monitoring devices.

[0026] On the other hand, according to the cell selection switch 20 according to the embodiment of the disclosed technology, the operating current I generated when the switch section 21 is in the on state Z is supplied from a path different from the conductive path P1 by the bias section 100. As a result, the current flowing through the resistance element 61 when the switch section 21 is in the on state can be suppressed. As a result, the voltage drop in the resistance element 61 can be suppressed when measuring the cell voltage, so that the measurement error of the cell voltage can be reduced.

[0027] [Second Embodiment] FIG. 4 is a diagram showing an example of the configuration of a cell selection switch 20A according to a second embodiment of the disclosed technology. The cell selection switch 20A includes a switch unit 31 and a switching unit 32. The switching unit 32 includes a current mirror circuit 34, switches 83A and 83B, a constant voltage element 35, and a bias unit 101. Note that the cell selection switch 20A is an example of the "second cell selection switch" in the disclosed technology. The switch unit 31 is an example of the "second switch unit" in the disclosed technology. The switching unit 32 is an example of the "second switching unit" in the disclosed technology. The constant voltage element 35 is an example of the "second constant voltage element" in the disclosed technology. The bias unit 101 is an example of the "second bias unit" in the disclosed technology.

[0028] The switch unit 31 is provided on a conductive path P1 extending from the positive electrode of the corresponding battery cell 50 to the analog-digital converter 40. The switch unit 31 includes two N-channel MOSFETs 81A and 81B connected in series. The MOSFETs 81A and 81B are power MOSFETs having a so-called DMOS configuration. The drain of the MOSFET 81A is connected to the positive electrode of the corresponding battery cell 50 via a connection terminal 11 and a resistance element 61, and the source is connected to the drain of the MOSFET 81B. The source of the MOSFET 81B is connected to the analog input of the analog-digital converter 40. The gates of the MOSFETs 81A and 81B are each connected to a node n13 to which the cathode of a Zener diode, which is the constant voltage element 35, is connected.

[0029] When both the MOSFETs 81A and 81B are turned on, the switch unit 31 is turned on and the conductive path P1 is in a conductive state. When a cell selection switch one level lower is also turned on, the positive and negative electrodes of the battery cell 50 are connected to the analog-digital converter 40, and a digital value corresponding to the cell voltage of the battery cell 50 is output from the analog-digital converter 40. On the other hand, when both the MOSFETs 81A and 81B are turned off, the switch unit 31 is turned off and the conductive path P1 is in a non-conductive state.

[0030] The current mirror circuit 34 has two N-channel MOSFETs 82A and 82B. The sources of the MOSFETs 82A and 82B are connected to the node n14 which is the connection point of the MOSFETs 81A and 81B respectively. The gates of the MOSFETs 82A and 82B are connected to the drain of the MOSFET 82A respectively. The drain of the MOSFET 82A is connected to the node n15, and the drain of the MOSFET 82B is connected to the node n13. The Zener diode which is the constant voltage element 35 has its anode connected to the source (node n14) of the MOSFET 82B and its cathode connected to the drain (node n13) of the MOSFET 82B.

[0031] One end of the switch 83A is connected to the node n15 and the other end is connected to the current source 36A. One end of the switch 83B is connected to the node n13 and the other end is connected to the current source 36B. The current source 36A injects a constant current with a current value I1 from the battery line VB. The current source 36B injects a constant current with a current value I2 from the battery line VB. In this embodiment, I1 = I2. It should be noted that I1 ≠ I2 may also be possible.

[0032] The bias unit 101 is a constant current source provided between the ground line and the node n14. The bias unit 101 supplies the operating current flowing through the cell selection switch 20A from a path different from the conductive path P1 when the switch unit 31 is in the on state.

[0033] The switching unit 32 switches the on / off state of the switch unit 31 by complementarily turning on and off the switches 83A and 83B according to the control by the control unit 12. When the switch 83A is in the on state and the switch 83B is in the off state, a current with a current value I1 flows through the current mirror circuit 34. As a result, the gate-source voltage of the MOSFETs 81A and 81B constituting the switch unit 31 becomes approximately 0V, and the MOSFETs 81A and 81B are in the off state (that is, the switch unit 31 is in the off state). On the other hand, when the switch 83A is in the off state and the switch 83B is in the on state, the Zener diode, which is the constant voltage element 35, breaks down, and an operating current I with a current value I2 flows through the constant voltage element 35, and a Zener voltage is generated across the constant voltage element 35. As a result, the gate-source of the MOSFETs 81A and 81B constituting the switch unit 31 is biased by the Zener voltage, and the MOSFETs 81A and 81B are in the on state (that is, the switch unit 31 is in the on state). The operating current I flowing through the constant voltage element 35 is drawn into the ground line by the bias unit 101. Z According to the cell selection switch 20A according to the second embodiment of the disclosed technology, the operating current I generated when the switch unit 31 is in the on state is supplied from a path different from the conductive path P1 by the bias unit 101. As a result, it is possible to suppress the current flowing through the resistance element 61 when the switch unit 31 is in the on state. As a result, when measuring the cell voltage, the voltage drop in the resistance element 61 can be suppressed, so that the measurement error of the cell voltage can be reduced. Z is drawn into the ground line by the bias unit 101.

[0034] According to the cell selection switch 20A according to the second embodiment of the disclosed technology, the operating current I generated when the switch unit 31 is in the on state is supplied from a path different from the conductive path P1 by the bias unit 101. As a result, it is possible to suppress the current flowing through the resistance element 61 when the switch unit 31 is in the on state. As a result, when measuring the cell voltage, the voltage drop in the resistance element 61 can be suppressed, so that the measurement error of the cell voltage can be reduced. Z is supplied from a path different from the conductive path P1 by the bias unit 101. As a result, it is possible to suppress the current flowing through the resistance element 61 when the switch unit 31 is in the on state. As a result, when measuring the cell voltage, the voltage drop in the resistance element 61 can be suppressed, so that the measurement error of the cell voltage can be reduced.

[0035] The cell selection switch 20 according to the first embodiment and the cell selection switch 20A according to the second embodiment are preferably used in combination. The cell selection switch 20 according to the first embodiment has an input voltage V CINSince it can be preferably used when, for example, it is 5V or higher, it is preferably used as a cell selection switch corresponding to a battery cell having a relatively high potential among the plurality of battery cells 50 constituting the assembled battery 51. On the other hand, the cell selection switch 20A according to the second embodiment has an input voltage V CIN Since it can be preferably used when it is 1V or higher and 5V or lower, it is preferably used as a cell selection switch corresponding to a battery cell having a relatively low potential among the plurality of battery cells 50 constituting the assembled battery 51.

[0036] FIG. 5 is a diagram showing an example of the configuration of the cell selection switch 20B that can be used in combination with the cell selection switches 20 and 20B. The cell selection switch 20B has a switch unit 41 and a switching unit 42. The switching unit 42 has an inverter 43. Note that the cell selection switch 20B is an example of the "third cell selection switch" in the disclosed technology. The switch unit 41 is an example of the "third switch unit" in the disclosed technology. The switching unit 42 is an example of the "third switching unit" in the disclosed technology.

[0037] The switch unit 41 is provided on a conductive path P1 from the positive electrode of the corresponding battery cell 50 to the analog-digital converter 40. The switch unit 41 has two N-channel type MOSFETs 91A and 91B connected in series. The MOSFETs 91A and 91B are power MOSFETs having a so-called DMOS configuration. The drain of the MOSFET 91A is connected to the positive electrode of the corresponding battery cell 50 via the connection terminal 11 and the resistance element 61, and the source is connected to the drain of the MOSFET 91B. The source of the MOSFET 91B is connected to the analog input of the analog-digital converter 40. The gates of the MOSFETs 91A and 91B are each connected to the output terminal of the inverter 43.

[0038] When both MOSFETs 91A and 91B are in the on state, the switch unit 41 is turned on, and the conduction path P1 is in the conductive state. When the one-level lower cell selection switch is also turned on, the positive and negative electrodes of the battery cell 50 are connected to the analog-to-digital converter 40, and a digital value corresponding to the cell voltage of the battery cell 50 is output from the analog-to-digital converter 40. On the other hand, when both MOSFETs 91A and 91B are in the off state, the switch unit 41 is turned off, and the conduction path P1 is in the non-conductive state.

[0039] The switching unit 42 switches the on / off state of the switch unit 41 according to the output signal of the inverter 43. When a high-level signal is input to the inverter 43, a low-level (0V) signal is output from the inverter 43, whereby MOSFETs 91A and 91B are in the off state (i.e., the switch unit 41 is in the off state). When a low-level input signal is input to the inverter 43, a high-level (5V) signal is output from the inverter 43, whereby MOSFETs 91A and 91B are in the on state (i.e., the switch unit 41 is in the on state). Thus, when the switching unit 42 turns on the switch unit 41, a constant voltage (5V) is supplied to the gates of MOSFETs 91A and 91B.

[0040] The cell selection switch 20B can be preferably used when the input voltage V CIN is 4V or less. Therefore, among the plurality of battery cells 50 constituting the battery pack 51, it is preferably used as the cell selection switch corresponding to the battery cell at a relatively low potential including the lowermost one.

Explanation of Reference Numerals

[0041] 10 Battery monitoring device 20, 20A, 20B Cell selection switch 21 31, 41 Switch unit 25, 35 Constant voltage element 40 Analog-to-digital converter 50 Battery cell 51 Battery pack 61 Resistance element 100 and 101 bias sections P1 conductive path

Claims

1. an analog-digital converter, a first cell selection switch for selectively connecting any one of a plurality of battery cells to the analog-digital converter, and having, the first cell selection switch, is provided on a conduction path from one of the plurality of battery cells to the analog-digital converter, and has a first switch portion that makes the conduction path conductive in the on state and non-conductive in the off state, a first switching portion that switches the on / off of the first switch portion and supplies a current flowing through the first cell selection switch from a path different from the conduction path when the first switch portion is in the on state, a battery monitoring device having the above.

2. the first switch portion includes a P-channel type transistor provided on the conduction path, the first switching portion has a first constant voltage element that generates a voltage applied between the gate and source of the P-channel type transistor when turning on the first switch portion, the first bias portion supplies a current flowing through the first constant voltage element, the battery monitoring device according to claim 1.

3. further having a second cell selection switch for selectively connecting any one of the plurality of battery cells to the analog-digital converter, the second cell selection switch, is provided on a conduction path from one of the plurality of battery cells to the analog-digital converter, and has a second switch portion that makes the conduction path conductive in the on state and non-conductive in the off state, a second switching portion that switches the on / off of the second switch portion, and having, the second switch portion includes an N-channel type transistor provided on the conduction path, the second switching portion, when turning on the second switch portion, has a second constant voltage element that generates a voltage applied between the gate and source of the N-channel type transistor, and a second bias portion that supplies a current flowing through the second constant voltage element, and having, the battery monitoring device according to claim 2.

4. further having a third cell selection switch for selectively connecting any one of the plurality of battery cells to the analog-digital converter, the third cell selection switch, A third switch unit provided on a conductive path from one of the plurality of battery cells to the analog-to-digital converter, which makes the conductive path conductive in the on state and non-conductive in the off state; A third switching unit that switches the on / off of the third switch unit; and having The third switch unit includes an N-channel transistor provided on the conductive path. When the third switching unit turns on the third switch unit, a constant voltage is supplied to the gate of the N-channel transistor. The battery monitoring device according to claim 2 or claim 3.

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