JP4862760B2 - Detection signal processing circuit - Google Patents

Description

  The present invention relates to a detection signal processing circuit that generates a rectangular wave-shaped rotation detection signal having a signal level corresponding to the rotation direction of a rotating body, based on detection signals input from two sensors via signal output lines. .

  As a detection signal processing circuit of this type of sensor, for example, there is one described in Patent Document 1. FIG. 8 shows a configuration of a rotation angle detection device including this detection signal processing circuit. Two magnetoresistive elements 1 and 2 arranged opposite to a rotating body (not shown) constitute sensors 5 and 6 in the form of a half bridge together with resistors 3 and 4, respectively. The detection signal processing circuit 7 includes comparators 8 and 9, D flip-flop 10, transistors 11 and 12, and resistors 13 to 19, and a detection signal S 1 input from the sensors 5 and 6 through the signal output lines 20 and 21. The rotation detection signal Sr is generated based on S2. A comparison circuit 28 including comparators 22 and 23 and resistors 24 to 27 is connected to the subsequent stage of the detection signal processing circuit 7. The comparison circuit 28 compares two threshold voltages L1 and L2 different from the rotation detection signal Sr and outputs determination signals D1 and D2.

In this configuration, the detection signals S1 and S2 having a phase difference are binarized by the comparators 8 and 9, respectively. The D flip-flop 10 holds the detection signal B1 using the detection signal B2 of the binarized detection signals B1 and B2 as a clock, and converts the level of the detection signal B1 according to the hold signal Sh. During normal rotation of the rotating body, the holding signal Sh becomes H (high) level, and the rotation detection signal Sr changes between H level and M (mid) level in synchronization with the detection signal B1. On the other hand, the holding signal Sh becomes L (low) level during the reverse rotation of the rotating body, and the rotation detection signal Sr changes between the high level and the low level in synchronization with the detection signal B1.
Japanese Patent No. 3588044

  In the configuration described in Patent Document 1, when one chip is configured by the sensors 5 and 6 and another chip is configured by the detection signal processing circuit 7, the wires (signal output lines 20 and 21) between these chips are disconnected. In some cases, the rotation detection signal Sr and the determination signals D1 and D2 are not preferable in the rotation angle detection system. FIG. 9 shows a waveform when the signal output line 21 is disconnected during normal rotation.

  When the signal output line 21 is disconnected, the detection signal B2 becomes H level constant, and the clock to the D flip-flop 10 is interrupted. Therefore, the holding signal Sh becomes constant at the H level or the L level according to the detection signal B1 immediately before the disconnection, and the determination signals D1 and D2 continue to output one of the rotation directions regardless of the rotation direction of the rotating body. (The forward rotation direction is output in FIG. 9).

  As a result, for example, in a detection signal processing circuit of a rotation sensor used for engine control, there is a case where a rotation direction opposite to the actual one is detected, which may cause an injection timing error and cause backfire. However, when the signal output line 20 is disconnected, the detection signal B1 is constant at the H level and the rotation detection signal Sr is constant at the M level, so that the engine control system itself can be determined to be abnormal.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a detection signal processing circuit capable of preventing erroneous detection of the rotation direction due to disconnection of a signal output line from a sensor.

According to the first aspect of the present invention, the periodic first and second periodic signals input from the first and second sensors disposed opposite to the rotating body so as to have a phase difference from each other via each signal output line. Based on the detection signal 2, a rectangular wave-shaped rotation detection signal having a signal level corresponding to the rotation direction of the rotating body is generated. The holding circuit receives the first and second detection signals, and holds the level of the first detection signal when the second detection signal changes by a predetermined level. Since the detection signals from the two sensors have a phase difference, the held signal level differs depending on the rotation direction of the rotating body. The level conversion circuit converts the level of the first detection signal in accordance with the held signal level to generate a rotation detection signal having a rectangular wave shape.
In this configuration, the presence or absence of disconnection of the signal output line is detected by the disconnection detection circuit . When the disconnection of the signal output line is detected, the disconnection processing circuit blocks the input of the first detection signal to the level conversion circuit in a state where the first and second detection signals are input to the holding circuit. The output of the rectangular wave rotation detection signal is stopped. Accordingly , it is possible to prevent erroneous detection of the rotation direction due to the continuous output of the rectangular wave-shaped rotation detection signal even at the time of disconnection.

  According to the means described in claim 2, when the signal output line connected to the sensor is normally connected, the high resistance load circuit connected between the signal output line and the predetermined reference voltage line includes the sensor. Only a current smaller than the current flowing in the current flows. For this reason, the influence on the sensor due to the presence of the high resistance load circuit is small, and the original output voltage of the sensor itself becomes the detection signal almost as it is.

  Since the threshold voltage of the comparison circuit is set higher (or lower) than the output voltage range of the sensor at the normal time, the comparison circuit outputs a comparison result indicating a non-disconnection state. On the other hand, when the signal output line is disconnected, the voltage of the signal output line passes through the high resistance load circuit, and the voltage of the reference voltage line (the voltage exceeding the output voltage range of the sensor in the normal state and the above) The voltage exceeds the threshold voltage). As a result, the comparison circuit outputs a comparison result indicating a disconnected state.

According to the means described in claim 3 , the disconnection detection circuit detects disconnection of the signal output line connected to the second sensor. This is because when the signal output line connected to the first detection signal is disconnected, the first detection signal becomes constant and the level conversion circuit outputs a constant voltage. This is because the disconnection can be easily detected, whereas when the signal output line connected to the second sensor is disconnected, the level conversion circuit continues to output the rotation detection signal having a rectangular wave shape in accordance with the normal first detection signal. According to this means, the disconnection detection of the signal output line connected to the first sensor becomes unnecessary, and the configuration of the disconnection detection circuit can be further reduced.

According to the means described in claim 4 , the disconnection detection circuit operates intermittently for a predetermined period in a period excluding a time point when the second detection signal changes by a predetermined level. According to this intermittent operation, when the current flowing through the disconnection detection circuit cannot be made sufficiently smaller than the current flowing through the sensor due to a large resistance of the sensor or the like, at least the holding circuit has the level of the first detection signal. The operation of the disconnection detection circuit is stopped when holding. As a result, it is possible to avoid the influence on the sensor due to the operating current of the disconnection detection circuit (such as fluctuations in sensor output voltage), and to prevent deterioration in accuracy.

According to the means described in claim 5 , the disconnection detection circuit detects the first detection signal having the phase difference between the first detection signal and the second detection signal from the time when the level of the first detection signal changes. It operates for a predetermined period before the predetermined level change.

According to the means described in claim 6 , since the high resistance load circuit is constituted by a constant current circuit, the layout size of the high resistance load circuit is smaller than that of the high resistance load circuit. The high resistance load circuit may be composed of a high resistance element as in the means described in claim 7 .

According to the means described in claim 8 , each of the first and second sensors includes a magnetoresistive element, and is configured, for example, in the form of a half bridge or a full bridge. Thereby, the change of the magnetic resistance accompanying rotation of a rotary body can be converted into the change of a voltage, and can be detected.

According to the means described in claim 9 , the first and second sensors are provided in the first chip, and the detection signal processing circuit is provided in the second chip. The first chip and the second chip A signal output line is formed by wire bonding between the two. In such a configuration, the bonding wire (signal output line) may be broken, and the detection signal processing circuit of this means is suitable.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. 1 to 3.
FIG. 1 shows a configuration of a rotation angle detection device that detects a crank angle of an internal combustion engine and its rotation direction. The rotation angle detection device 31 includes a sensor chip 32 (corresponding to a first chip), a detection signal processing chip 33 (corresponding to a second chip), and an ECU 34 (Electronic Control Unit).

  A rotor (rotary body) is fixed to the crankshaft of the vehicle, and a plurality of teeth are provided on the outer periphery of the rotor so as to generate pulse signals at predetermined intervals. The sensor chip 32 includes a first sensor 39 having a full bridge configuration in which magnetoresistive elements (MRE) 37 and 38 are connected in series between power supply lines 35 and 36, and a magnetoresistive element 40 between the power supply lines 35 and 36. , 41 in series, and a second sensor 42 in the form of a full bridge. These sensors 39 and 42 are disposed opposite to the rotor and are shifted in the circumferential direction of the rotor so as to output signals having a phase difference from each other. The full-bridge sensors 39 and 42 have an advantage that the amplitudes of the detection signals S1 and S2 are larger than that of the half-bridge sensor.

  The sensor chip 32 and the detection signal processing chip 33 are connected by signal output lines 43 and 44 formed by wire bonding. The detection signal processing chip 33 is formed with a detection signal processing circuit 45 that operates by receiving a power supply voltage Vcc (for example, 5 V) from the power supply lines 35 and 36.

  The comparator 46 compares the first detection signal S1, which is a periodic analog signal input via the signal output line 43, with the reference voltage V1 generated by the resistors 47, 48, and is a digital signal. The detection signal B1 is output. Similarly, the comparator 49 compares the second detection signal S2, which is a periodic analog signal input via the signal output line 44, with the reference voltage V2 generated by the resistors 50, 51, and performs digital comparison. A detection signal B2, which is a signal, is output. The reference voltages V1 and V2 are set to 2.5V corresponding to the median value of the change widths of the detection signals S1 and S2, respectively.

  The detection signal processing circuit 45 stops the output of the rotation detection signal Sr (described later) when the disconnection detection circuit 52 detects the disconnection of the signal output line 44, and the disconnection detection circuit 52 detects the disconnection of the signal output line 44. And an AND gate 53 (corresponding to a disconnection processing circuit). The disconnection detection circuit 52 includes a constant current circuit 54 connected between an end (node N2) of the signal output line 44 on the detection signal processing chip 33 side and a power supply line 36 (corresponding to a reference voltage line), a threshold value Resistors 55 and 56 for generating a voltage Va (for example, 1.25 V), and a comparator 57 (corresponding to a comparison circuit) for comparing the voltage at the node N2 with the threshold voltage Va.

  Here, the constant current circuit 54 corresponds to a high resistance load circuit, and outputs a minute current sufficiently smaller than the current flowing through the sensor 42. FIG. 2 shows an example of a constant current circuit 54 configured using a MOSFET. The FETs 82 and 83, the FETs 84 and 85, and the FETs 86 and 87 constitute a current mirror circuit having a mirror ratio of 10: 1, respectively. A current (0.1 μA) is output.

  The AND gate 53 receives the detection signal B1 described above and the disconnection detection signal Sb output from the disconnection detection circuit 52, and controls passage and cutoff of the detection signal B1 according to the level of the disconnection detection signal Sb. is there.

  The D flip-flop 58 (corresponding to a holding circuit) holds the first detection signal B1 when the second detection signal B2 changes from the L level to the H level, and has a D (data) terminal, a CLK (clock). ) Terminal and R / (reset) terminal are inputted with detection signal B1, detection signal B2, and disconnection detection signal Sb, respectively. The AND gate 59 receives the output signal of the AND gate 53 and the non-inverted output signal (signal QP) of the D flip-flop 58, and drives the transistor 61 by the output signal. Similarly, the AND gate 60 receives the output signal of the AND gate 53 and the inverted output signal (signal QN) of the D flip-flop 58, and drives the transistor 62 by the output signal.

  The collector of the transistor 61 is connected to the collector of the transistor 62 via the resistor 63, and the collector of the transistor 62 is pulled up to the power supply line 35 via the resistor 19 of the ECU 34 connected by the signal output line 64. . These AND gates 59 and 60, transistors 61 and 62, and resistors 19 and 63 constitute a level conversion circuit 65.

  The ECU 34 shown in FIG. 1 inputs a cam angle detection signal, a detection signal from a throttle opening sensor, a combustion pressure sensor, and the like in addition to a crank angle detection signal, and executes predetermined calculation processing. . Since the comparison circuit in the ECU 34 has the same configuration as the comparison circuit 28 shown in FIG. The comparison circuit 28 compares the rotation detection signal Sr on the signal output line 64 with the threshold voltages L1 and L2, and outputs determination signals D1 and D2. Between the threshold voltage L1 generated by the resistors 24 and 25 and the threshold voltage L2 generated by the resistors 26 and 27, Vcc (H level)> L1> Vm (M level)> L2> The relationship of 0V (L level) is established.

Next, the operation of this embodiment will be described with reference to FIG.
FIG. 3 is a waveform diagram of the rotation angle detection device 31 when the crankshaft rotor (rotating body) is rotating forward. Detection signal S1, S2, detection signal B1, detection signal B2, holding signal QP, output signal of AND gate 59, output signal of AND gate 60, rotation detection signal Sr, determination signal D1, and determination signal D2 are shown in order from the top. Yes. FIG. 3A shows a case where the signal output lines 43 and 44 are not disconnected, and FIG. 3B shows a case where the signal output line 44 is disconnected.

First, the case where the signal output lines 43 and 44 are not disconnected will be described.
The detection signals S1 and S2 have a width of several tens of mV, for example, about 2.5 V which is 1/2 of Vcc, depending on the distance between the teeth provided on the outer periphery of the rotor and the sensors 39 and 42, respectively. Change periodically. Since the sensors 39 and 42 are arranged so as to be shifted in the circumferential direction of the rotor, the phase of the detection signal S1 advances during forward rotation, and the phase of the detection signal S2 advances during reverse rotation. The binarized detection signals B1 and B2 have the same phase relationship.

  At this time, a minute current (0.1 μA) flows from the power supply line 35 to the constant current circuit 54 via the magnetoresistive element 40 and the signal output line 44. The resistance of the magnetoresistive element 40 is about 1 kΩ, and the voltage change applied to the detection signal S2 due to the flow of this minute current is about 0.1 mV. On the other hand, as described above, the detection signal S2 has a change width of several tens of mV centering on 2.5V, so that the influence on the detection signal S2 due to the provision of the constant current circuit 54 becomes sufficiently small.

  The disconnection detection circuit 52 compares the detection signal S2 (the voltage of the node N2) with a threshold voltage Va (1.25V) having a voltage value that is ½ of the center voltage 2.5V, and outputs an H level ( A non-breaking) disconnection detection signal Sb is output. Accordingly, the AND gate 53 passes the detection signal B1 as it is.

  During forward rotation, the holding signal QP is at the H level and the holding signal QN is at the L level, the transistor 62 is turned off, and the transistor 61 is turned on / off according to the detection signal B1. Since the resistance values of the resistors 19 and 63 are equal, the rotation detection signal Sr changes between the H level (5 V) and the M level (2.5 V). If the threshold voltages L1 and L2 in the comparison circuit 28 are set to 3.75 V and 1.25 V, for example, the determination signal D1 changes in synchronization with the rotation detection signal Sr (detection signal B1), and the determination signal D2 is at the L level. It becomes constant.

  At the time of reverse rotation, the holding signal QP becomes L level and the holding signal QN becomes H level, the transistor 62 is turned on / off according to the detection signal B1, and the transistor 61 is turned off. At this time, the rotation detection signal Sr changes between the H level (5 V) and the L level (0 V), and the determination signals D1 and D2 both change in synchronization with the rotation detection signal Sr (detection signal B1). The ECU 34 detects the crank angle and the rotation direction based on the determination signals D1 and D2.

Next, a case where the signal output line 43 is connected and the signal output line 44 is disconnected will be described.
When the signal output line 44 is disconnected, the voltage of the node N2 is fixed to 0 V by the action of the constant current circuit 54, and the disconnection detection signal Sb becomes L level (disconnected). As a result, the AND gate 53 blocks the input of the detection signal B1 to the level conversion circuit 65, and the D flip-flop 58 is reset. At this time, the output signals of the AND gates 59 and 60 become L level, and both the transistors 61 and 62 are turned off. As a result, the rotation detection signal Sr becomes constant at the H level, and both the determination signals D1 and D2 become constant at the L level.

  When the signal output line 44 is connected and the signal output line 43 is disconnected, the disconnection detection signal Sb becomes H level (non-disconnected), and the CLK terminal of the D flip-flop 58 has a rectangular wave shape. A detection signal B2 is given. However, since the detection signal B1 is constant at H level, the transistor 61 is turned on, the transistor 62 is turned off, the rotation detection signal Sr is constant at M level, the determination signal D1 is constant at H level, and the determination signal D2 is constant at L level. Become.

  That is, when one of the signal output lines 43 and 44 is disconnected, the change in the determination signals D1 and D2 is stopped. When the ECU 34 determines that the rotor (rotating body) of the crankshaft is in a stopped state based on the cam angle detection signal or the like, the ECU 34 determines that the crankshaft rotor is in a stopped state. Perform error handling. The above-described operation is the same even when the rotation is reversed.

  As described above, the rotation angle detection device 31 of the present embodiment includes the disconnection detection circuit 52 that detects disconnection of the signal output line 44 that connects the sensor chip 32 and the detection signal processing chip 33, and detects when disconnection is detected. Since the input of the signal B1 to the level conversion circuit 65 is cut off, when the signal output line 44 (bonding wire) is disconnected, the rotation detection signal Sr and the detection signal B1 in the determination signals D1 and D2 are synchronized. Level change stops.

  Thereby, the ECU 34 can detect a disconnection abnormality not only when the signal output line 43 is disconnected but also when the signal output line 44 is disconnected, and the determination signals D1 and D2 are in the normal rotation (or inversion) state regardless of the rotation direction. It is possible to reliably prevent erroneous detection of the rotation direction due to continuing to present. Further, since only the disconnection of the signal output line 44 among the signal output lines 43 and 44 is detected, the circuit scale of the detection signal processing circuit 45 (the size of the detection signal processing chip 33) can be reduced.

  Since the constant current circuit 54 constituting the disconnection detection circuit 52 is configured using a MOSFET, the mirror ratio can be set large while suppressing the element size, and a minute current sufficiently smaller than the current flowing through the sensor 42 can be output. It becomes. As a result, the influence on the sensor 42 due to the presence of the constant current circuit 54 is reduced, and the voltage error of the detection signal S2 can be sufficiently reduced.

  Since the disconnection detection signal Sb is input to the R / (reset) terminal of the D flip-flop 58, the determination signals D1 and D2 at the time of starting the rotation of the rotor after the power is turned on are uniquely determined (not indefinite state). . However, the input to the reset terminal is not necessarily required in the present invention.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIGS.
A rotation angle detection device 66 shown in FIG. 4 is configured such that the disconnection detection circuit 52 of the rotation angle detection device 31 shown in FIG. 1 can be intermittently operated. In the detection signal processing chip 67, a detection signal processing circuit 70 including an intermittent signal generation circuit 68 and a latch 69 is formed.

  The intermittent signal generation circuit 68 generates an intermittent signal Sc that is H level for a predetermined period from the time when the level of the detection signal B1 changes until the time when the level of the detection signal B2 changes. The structure shown is provided. Resistors 71 and 72 are connected in series between the power supply lines 35 and 36, and a reference voltage Vb is generated. Further, a resistor 73 and a capacitor 74 are connected in series between the output terminal of the comparator 46 and the power supply line 36, and an integrated voltage Vc is generated. The comparator 75 inputs the reference voltage Vb and the integrated voltage Vc, and the ExOR gate 76 inputs the output signal of the comparator 75 and the detection signal B1 and outputs the intermittent signal Sc.

  FIG. 6 shows an operation waveform of the intermittent signal generation circuit 68. When the level of the detection signal B1 changes, the integrated voltage Vc changes with a time constant determined by the resistance value of the resistor 73 and the capacitance value of the capacitor 74, and the phase of the output signal of the comparator 75 is delayed with respect to the detection signal B1. The intermittent signal Sc is at the H level only during the period corresponding to this phase difference.

  The constant current circuit 54 and the comparator 57 of the disconnection detection circuit 52 operate only when the intermittent signal Sc is at the H level, and the current consumption becomes substantially zero when the intermittent signal Sc is at the L level. The latch 69 passes the disconnection detection signal Sb as it is when the intermittent signal Sc is at the H level, and holds the level of the disconnection detection signal Sb immediately before it when the intermittent signal Sc becomes the L level.

  FIG. 7 is a waveform diagram of each signal related to the intermittent operation. The detection signals S1 and S2, the detection signal B1, the detection signal B2, and the intermittent signal Sc are shown in order from the top. The intermittent signal Sc is a pulse signal that changes from the L level to the H level when the level of the detection signal B1 changes, and then returns to the L level when the level of the detection signal B2 changes thereafter.

  In the rotation angle detection device 66 of the present embodiment, the output current of the constant current circuit 54 is sufficiently smaller than the current flowing through the sensor 42 because the resistance values of the magnetoresistive elements 40 and 41 constituting the sensor 42 are high. This is particularly effective when current cannot be used. When the constant current circuit 54 is operated in such a case, the voltage of the detection signal S2 is lower than the original voltage, the phase of the detection signal B2 is shifted, and an error occurs in the level held by the D flip-flop 58. There is a fear.

  According to the present embodiment, since the operation of the constant current circuit 54 is stopped at least when the level of the detection signal B2 changes, the voltage fluctuation of the detection signal B2 due to the flow of the constant current does not occur, and the rotation Misdetection of direction can be prevented. Further, since the operation of the entire disconnection detection circuit 52 including the constant current circuit 54 and the comparator 57 is stopped by the intermittent signal Sc, the rotation direction can be detected more reliably without the fluctuation or decrease of the power supply voltage Vcc due to these operating currents. In addition, the current consumption of the detection signal processing chip 67 can be reduced.

(Other embodiments)
The present invention is not limited to the embodiments described above and shown in the drawings, and can be modified or expanded as follows, for example.
The sensor only needs to use a resistive detection element, and may be a pressure sensor, an acceleration sensor, or the like, for example.
A rotation angle detection device that detects the angle of the cam shaft and the rotation direction thereof may be used.
Instead of the constant current circuit 54, a high resistance element (corresponding to a high resistance load circuit) may be used. However, the use of the constant current circuit 54 has an advantage of reducing the layout size.
A plurality of bonding wires for the signal output lines 43 and 44 may be used.

The block diagram of the rotation angle detection apparatus which shows the 1st Embodiment of this invention Configuration diagram of constant current circuit Waveform diagram of the rotation angle detection device during normal rotation FIG. 1 equivalent diagram showing a second embodiment of the present invention Configuration diagram of intermittent signal generation circuit Waveform diagram of intermittent signal generation circuit Waveform diagram related to intermittent operation 1 equivalent diagram showing the prior art Waveform diagram of the rotation angle detector when the signal output line is disconnected during normal rotation

Explanation of symbols

  32 is a sensor chip (first chip), 33 and 67 are detection signal processing chips (second chip), 36 is a power supply line (reference voltage line), 37, 38, 40 and 41 are magnetoresistive elements, 39, 42 is a sensor (first and second sensors), 43 and 44 are signal output lines, 45 and 70 are detection signal processing circuits, 52 is a disconnection detection circuit, 53 is an AND gate (disconnection processing circuit), and 54 is a constant current. A circuit (high resistance load circuit), 57 is a comparator (comparison circuit), 58 is a D flip-flop (holding circuit), and 65 is a level conversion circuit.

Claims (9)

Based on periodic first and second detection signals input from the first and second sensors disposed opposite to the rotating body so as to have a phase difference from each other via each signal output line, the rotating body In a detection signal processing circuit that generates a rectangular wave-shaped rotation detection signal having a signal level corresponding to the rotation direction of
A holding circuit that inputs the first and second detection signals and holds the level of the first detection signal at the time when the second detection signal changes by a predetermined level;
A level conversion circuit that converts the level of the first detection signal according to the signal level held by the holding circuit and generates the rotation detection signal;
A disconnection detection circuit for detecting disconnection of the signal output line;
When the disconnection detection circuit detects disconnection of the signal output line , the first detection signal is input to the level conversion circuit while the first and second detection signals are input to the holding circuit. A detection signal processing circuit comprising: a disconnection processing circuit that stops output of the rotation detection signal in the form of a rectangular wave by interrupting . The disconnection detection circuit includes:
A high resistance load circuit that is connected between the signal output line and a predetermined reference voltage line and flows a current smaller than a current flowing through the sensor;
2. The comparison circuit according to claim 1, further comprising a comparison circuit for comparing the detection signal inputted through a signal output line connected to the high resistance load circuit with a predetermined threshold voltage. Detection signal processing circuit. Before SL disconnection detecting circuit, the first, the detection of claim 1, wherein detecting the disconnection of a signal output line connected to a second sensor of the respective signal output line connected to the second sensor Signal processing circuit. The disconnection detecting circuit, a detection signal according to any one of claims 1 to 3, characterized in that said second detection signal to operate only intermittently a predetermined time period excluding the time of the predetermined level change Processing circuit. The disconnection detection circuit operates for a predetermined period from when the level of the first detection signal changes to before the second detection signal changes the predetermined level. Item 5. A detection signal processing circuit according to Item 4 . 3. The detection signal processing circuit according to claim 2, wherein the high resistance load circuit is a constant current circuit. 3. The detection signal processing circuit according to claim 2, wherein the high resistance load circuit is a high resistance element . It said first, second sensor, the detection signal processing circuit according to any one of claims 1 to 7, characterized in that it is configured to include a magnetoresistance element. The first and second sensors are provided in a first chip, the detection signal processing circuit is provided in a second chip, and wire bonding is performed between the first chip and the second chip. 9. The detection signal processing circuit according to claim 1, wherein the signal output line is formed .

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