JP7175867B2 - Current detection device and data writing method - Google Patents

Description

The present invention relates to a current detection device and a data writing method.

A current detection device is known that has a Hall IC and a microcomputer that converts an analog signal from the Hall IC into a digital signal and detects a current flowing through a motor.
A Hall IC detects a magnetic field or magnetic flux generated by a current flowing through a conductor, and a Hall element that outputs a voltage signal corresponding to the detected magnetic field or magnetic flux; and a processing circuit for outputting the voltage signal (sensor signal) generated by the microcomputer to the microcomputer.

In order to adjust the amplification factor, a voltage (hereinafter referred to as "write voltage") higher than a normal power supply voltage (for example, 5 V) is applied to the power supply terminal of the Hall IC to shift the Hall IC to the write mode. There is a need. By writing predetermined data in the Hall IC in the write mode, the amplification factor can be adjusted to a desired value.

Here, the Hall IC and the AD converter of the microcomputer have ratiometric characteristics. Therefore, 5V is supplied from the same DC power supply so that the power supply voltage of the Hall IC and the power supply voltage of the microcomputer are always at the same potential during sensing. That is, the power terminal of the Hall IC and the power terminal of the microcomputer are electrically connected.

JP-A-6-186253

However, if a write voltage higher than 5 V is applied to the power supply terminal of the Hall IC in order to adjust the amplification factor of the Hall IC, the write voltage is also applied to the power supply terminal of the microcomputer, causing the microcomputer to malfunction. There is a risk that Therefore, it is necessary to remove the Hall IC from the substrate each time the amplification factor is adjusted, adjust the gain, and re-solder the Hall IC to the substrate on which the microcomputer is mounted after the gain adjustment. Therefore, gain adjustment work takes time and effort.

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and an object of the present invention is to enable efficient gain adjustment of a Hall IC.

(1) One aspect of the present invention includes a magnetoelectric conversion element that detects a magnetic field or magnetic flux and converts it into a voltage signal, and a sensor signal that is a signal obtained by amplifying the voltage signal with a predetermined amplification factor and outputs from a sensor output terminal. a hall IC, a processing device for converting the analog signal into a digital signal, and a first output terminal, generating a first voltage that is a power supply voltage of the processing device and transmitting the first voltage to the processing device from the first output terminal; A second DC power supply that has a first DC power supply that outputs to a power supply terminal and a second output terminal, generates a second voltage that is higher than the first voltage, and outputs the second voltage from the second output terminal; a voltage generator for generating the third voltage, which is a power supply voltage of the Hall IC, from the second voltage and outputting the third voltage to the Hall IC, wherein the voltage generator is connected to a power supply terminal of the processing device. a first terminal connected to the second output terminal; a third terminal connected to a power supply terminal of the Hall IC; a voltage value of the third voltage; a voltage replicating unit that controls the voltage value of the third voltage so that the voltage value of the first voltage input to one terminal is the same as that of the first voltage, and outputs the third voltage from the third terminal; and a current detection device.

(2) In the current detection device of (1) above, the Hall IC and the processing device may be mounted on the same substrate.

(3) In the current detection device of (2) above, when a write voltage higher than the second voltage is applied to the power supply terminal of the Hall IC, the Hall IC A write mode in which data can be written may be entered.

(4) One aspect of the present invention is, in the current detection device of (3) above, a method for writing data to the Hall IC, wherein the writing voltage is applied to a power supply terminal of the Hall IC to write the Hall IC. an application step for shifting the IC to a write mode; and a write step for writing the setting of the amplification factor to the Hall IC by inputting the data indicating the amplification factor to the power supply terminal of the Hall IC in the write mode. It is a data writing method including.

(5) In the data writing method of (4) above, the Hall IC has a sensor output terminal for outputting the analog signal, and a voltage follower is connected to a connection line connecting the sensor output terminal and the processing device. a first connection step of connecting circuits in parallel; and a second connection step of connecting the connection line between the voltage follower circuit and the processing device and the first output terminal via a diode, The applying step may be performed after the first connecting step and the second connecting step.

As described above, according to the present invention, it is possible to efficiently adjust the gain of the Hall IC.

1 is a diagram showing an example of a schematic configuration of a data writing system A having a current detection device according to this embodiment; FIG. It is a figure which shows an example of schematic structure of the voltage generation part 7 which concerns on this embodiment. 2 is a diagram of a writing device 2 according to the present embodiment connected to a current detection device 1. FIG. It is a figure explaining the flow of the data write method which concerns on this embodiment.

A current detection device and a data writing method according to this embodiment will be described below with reference to the drawings.

FIG. 1 is a diagram showing an example of a schematic configuration of a data writing system A having a current detection device according to this embodiment. As shown in FIG. 1, the data writing system A includes a current detection device 1 and a writing device 2. As shown in FIG.

The current detection device 1 detects a current to be measured in a non-contact manner. For example, the current detection device 1 detects current flowing in a motor mounted on a vehicle as a current to be measured. Therefore, the current detection device 1 may be mounted on a vehicle. The vehicle is, for example, a hybrid vehicle or an electric vehicle. The motor is, for example, a drive motor for driving a vehicle.

The writing device 2 is a device that writes data to the current detection device 1 . Note that the current detection device 1 and the writing device 2 are configured separately. Therefore, the writing device 2 is not mounted on the vehicle. That is, the writing device 2 is connected to the current detection device 1 when writing data to the current detection device 1 . However, the present invention is not limited to this, and the current detection device 1 and the writing device 2 may be integrated.

The configuration of the current detection device 1 according to this embodiment will be described below.

The current detection device 1 includes a Hall IC 3 , a microcomputer 4 , a first DC power supply 5 , a second DC power supply 6 and a voltage generator 7 . The microcomputer 4 is an example of the "processing device" of the present invention. The Hall IC 3 and the microcomputer 4 may be mounted on the same substrate, or may be mounted on separate substrates.

The Hall IC 3 includes a power terminal 31 , a ground terminal 32 , a sensor output terminal 33 , a magnetoelectric conversion element 34 and a signal processing section 35 . The Hall IC 3 is an integrated circuit (IC) in which a magnetoelectric conversion element 34 and a signal processing section 35 are mounted in one package.
The signal processing unit 35 includes a processor such as a CPU (Central Processing Unit) or MPU (Micro Processing Unit) and a nonvolatile or volatile semiconductor memory (e.g., RAM (Random Access Memory), ROM (Read Only Memory), flash memory , EPROM (Erasable Programmable Read Only Memory), EEPROM (Electrically Erasable Programmable Read Only Memory)).

The power supply terminal 31 functions as a power supply terminal for driving the Hall IC 3 . Therefore, the Hall IC 3 operates using the power supply voltage Vh (eg, 5V) input to the power supply terminal 31 as a drive source. The power supply terminal 31 also functions as a supply terminal of a write voltage Vw for shifting to a write mode in which data can be written to the Hall IC 3 . Furthermore, the power supply terminal 31 also functions as an input terminal for inputting data to the Hall IC 3 when the Hall IC 3 is in the write mode.

The ground terminal 32 is a terminal grounded to the ground (GND).

The sensor output terminal 33 outputs a sensor signal, which is an analog signal, in the normal operation mode. Hall IC 3 has ratiometric characteristics. That is, in the Hall IC 3, when the power supply voltage Vh input to the power supply terminal 31 fluctuates, the voltage value of the sensor signal output from the sensor output terminal 33 also fluctuates in proportion to the fluctuation.

The magnetoelectric conversion element 34 detects a magnetic field or magnetic flux generated by the current flowing through the conductor, and converts it into a voltage (hereinafter referred to as a "voltage signal") corresponding to the strength of the detected magnetic field or magnetic flux. do. Then, the magnetoelectric conversion element 34 outputs the voltage signal to the signal processing section 35 . For example, the magnetoelectric conversion element 34 is a Hall element, a magnetoresistive element, or a magnetic diode. In this embodiment, the magnetoelectric conversion element 34 is a Hall element.

The signal processing unit 35 amplifies the voltage value of the voltage signal output from the magnetoelectric conversion element 34 with a predetermined amplification factor G, and outputs the sensor signal, which is the amplified voltage signal, from the sensor output terminal 33 . This sensor signal is an analog signal.

This amplification factor G can be adjusted from the outside. Specifically, the signal processing unit 35 has a memory (for example, the semiconductor memory described above), and in the normal mode, data indicating the amplification factor stored in the memory (hereinafter referred to as "amplification factor data"). is read, and the voltage signal is amplified by the amplification factor indicated by the amplification factor data. Therefore, the user can adjust the amplification factor G by writing the amplification factor data into the memory using the writing device 2 . Note that "writing" includes rewriting of amplification factor data. Here, the normal mode is a mode in which the voltage signal from the signal processing unit 35 is amplified and output from the sensor output terminal 33, and is different from the write mode.

Specifically, when a voltage equal to or higher than the write voltage Vw (e.g., 8V) higher than the power supply voltage Vh (e.g., 5V) is input to the power supply terminal 31, the signal processing unit 35 enters the normal mode. to write mode. When the voltage of the power supply terminal 31 is lower than the write voltage Vw and lower than the normal mode transition voltage Vk which is higher than the power supply voltage Vh, the signal processing unit 35 switches from the write mode to the normal mode. Transition.
In the write mode, the signal processing unit 35 is in a state in which it is possible to communicate with the writing device 2 via the power supply terminal 31, and writing to the memory in the signal processing unit 35 by the writing device 2 is permitted. Become. Therefore, when the signal processing unit 35 is in the write mode, the write device 2 inputs the amplification factor data to the power supply terminal 31 with a pulse signal having a write voltage Vw or higher.

In the write mode, the signal processing unit 35 outputs amplification factor data and acknowledge (ACK) written in the memory of the signal processing unit 35 from the sensor output terminal 33 .

Next, the configuration of the microcomputer 4 according to this embodiment will be described.

The microcomputer 4 includes a power terminal 41 , a ground terminal 42 , an input terminal 43 and a signal processing section 44 . The signal processing unit 44 includes processors such as CPU (Central Processing Unit) or MPU (Micro Processing Unit) and non-volatile or volatile semiconductor memory (e.g., RAM (Random Access Memory), ROM (Read Only Memory), flash memory , EPROM (Erasable Programmable Read Only Memory), EEPROM (Electrically Erasable Programmable Read Only Memory)).

The power terminal 41 functions as a terminal for driving the microcomputer 4 . Therefore, the microcomputer 4 operates using the power supply voltage Vm (eg, 5 V) input to the power supply terminal 41 as a drive source.

The ground terminal 42 is a terminal grounded to the ground (GND).

The input terminal 43 is connected to the sensor output terminal 33 via a connection line L. As shown in FIG. A sensor signal is input to the input terminal 43 via the connection line L. As shown in FIG. For example, the input terminal 43 may be a so-called I/O port.

The signal processing unit 44 takes in the sensor signal from the sensor output terminal 33 and performs AD conversion to convert the sensor signal into a digital signal. That is, the signal processing unit 44 has an AD converter that converts the sensor signal into a digital signal. Then, the signal processing section 44 obtains the current value of the current to be measured based on the digital signal. Thereby, the current detection device 1 detects the current to be measured. Note that the AD converter has a ratiometric characteristic.

The first DC power supply 5 has a first output terminal 51 and generates a first voltage Vcc which is a DC voltage. This first voltage Vcc corresponds to the power supply voltage Vm of the microcomputer 4 and is, for example, 5V. The first DC power supply 5 outputs the generated first voltage Vcc from the first output terminal 51 to the power supply terminal 41 and the voltage generator 7 .

The second DC power supply 6 has a second output terminal 61 and generates a second voltage Vx higher than the first voltage Vcc. For example, the second voltage Vx is 6V. The second DC power supply 6 outputs the generated second voltage Vx from the second output terminal 61 .

The voltage generator 7 is supplied with the second voltage Vx from the second DC power supply 6 and generates the third voltage Vs from the second voltage Vx. The third voltage Vs corresponds to the power supply voltage Vh of the Hall IC 3 and is, for example, 5V. The voltage generator 7 outputs the generated third voltage Vs to the power supply terminal 31 of the Hall IC 3 . Here, the first voltage Vcc is input to the voltage generator 7, and the voltage generator 7 adjusts the third voltage Vs so that the voltage value of the third voltage Vs is the same as the first voltage Vcc. to control the voltage value of Thereby, the voltage value of the third voltage Vs is controlled so as to follow the voltage value of the first voltage Vcc. Thus, the voltage generator 7 is a voltage regulator that always outputs the third voltage Vs that is the same voltage value as the input first voltage Vcc.
An example of the schematic configuration of the voltage generator 7 according to this embodiment will be described below with reference to FIG. However, the voltage generator 7 is not particularly limited to the configuration shown in FIG. 2, and always outputs the third voltage Vs, which has the same voltage value as the input first voltage Vcc, from the second voltage Vx. It is sufficient if it has a configuration.

As shown in FIGS. 1 and 2 , the voltage generator 7 includes a first terminal 71 , a second terminal 72 , a third terminal 73 and a fourth terminal 74 and a voltage replicator 75 .

The first terminal 71 is connected to the power terminal 41 and the first output terminal 51 of the microcomputer 4 . Therefore, the first voltage Vcc is input to the first terminal 71 .

The second terminal 72 is connected to the second output terminal 61 . Therefore, the second voltage Vx is input to the second terminal 72 .

The third terminal 73 is connected to the power terminal 31 of the Hall IC 3 . Since the third voltage Vs is always output from the third terminal 73, the third voltage Vs is always input to the power supply terminal 31 of the Hall IC 3 in the normal mode.

The fourth terminal 74 is a ground terminal and is grounded to the ground (GND).

The voltage replication unit 75 steps down the second voltage Vx input to the second terminal 72 to generate the third voltage Vs. Here, in generating the third voltage Vs, the voltage replicating unit 75 sets the voltage value of the third voltage Vs to be the same as the voltage value of the first voltage Vcc input to the first terminal 71. constantly controls the voltage value of the third voltage Vs, and outputs the third voltage Vs from the third terminal 73 .

The voltage replicating section 75 includes a transistor 80 and a control section 81 .

Transistor 80 is a PNP bipolar transistor. The emitter E of the transistor 80 is connected to the second terminal 72 . A third terminal 73 is connected to the collector C of the transistor 80 . A control section 81 is connected to the base B of the transistor 80 .
The transistor 80 steps down the voltage input to the emitter E according to the base voltage applied to the base B. FIG. Then, the transistor 80 outputs from the collector C the stepped-down voltage.

The control section 81 takes in the first voltage Vcc from the first terminal 71 . Also, the control unit 81 takes in the third voltage Vs from the third terminal 73 . Then, the control section 81 controls the base voltage so that the potential difference between the first voltage Vcc and the third voltage Vs disappears. For example, the control section 81 may have an error amplifier circuit that amplifies the potential difference between the first voltage Vcc and the third voltage Vs, and may control the base voltage based on the output of this error amplifier circuit.
As a result, the control unit 81 prevents the voltage of the power terminal 31 from affecting the voltage of the power terminal 41 and prevents the voltage of the power terminal 31 (power voltage Vh) and the voltage of the power terminal 41 when the Hall IC 3 is in the normal mode. (power supply voltage Vm) can be controlled to be substantially the same at all times. Therefore, in adjusting the amplification factor G, the gain can be adjusted without removing the Hall IC 3 from the substrate, and the gain of the Hall IC 3 can be adjusted efficiently.

Next, a schematic configuration of the writing device 2 according to this embodiment will be described with reference to FIGS. 1 and 3. FIG. FIG. 3 is a diagram of the writing device 2 connected to the current detection device 1. As shown in FIG.

The writing device 2 includes an output section 21 and an output adjustment circuit 22 .

The output section 21 includes a voltage applying section 90 and a writing section 91 .

The voltage application unit 90 generates and outputs a write voltage Vw. The output terminal of the voltage applying section 90 is connected to the power terminal 31 via the connection line L2. The voltage application unit 90 applies the write voltage Vw to the power supply terminal 31 via the connection line L2, thereby shifting the Hall IC 3 from the normal mode to the write mode.

When the signal processing unit 35 is in the write mode, the write unit 91 inputs the amplification factor data to the power supply terminal 31 with a pulse signal having a write voltage Vw or more, thereby writing the amplification factor data into the memory of the signal processing unit 35. . Thereby, the user can adjust the amplification factor G to a desired value by using the writing device 2 .

The output adjustment circuit 22 has a voltage follower circuit 100 and a diode 101 .
The voltage follower circuit 100 is a circuit that has an operational amplifier and performs impedance conversion. This voltage follower circuit 100 is connected in parallel to the connection line L1.

In the write mode, the sensor output terminal 33 outputs the amplification factor data written in the memory of the signal processing unit 35 and an acknowledgment (ACK). ) flows. At this time, since a voltage equal to or higher than the write voltage Vw is applied to the power supply terminal 31, the output current increases. As a result, the rated output current of the Hall IC 3 may be exceeded. Therefore, in the write mode, the voltage follower circuit 100 is connected in parallel to the connection line L1 to output current from the voltage follower circuit 100 to the input terminal 43 instead of from the sensor output terminal 33 . That is, the output current from the Hall IC 3 can be suppressed below the rating by the voltage follower circuit 100 bearing the output current.

Here, as shown in FIG. 3, resistors R1 to R4 may be connected to the connection line L1.
The resistor R1 has one end connected to the sensor output terminal 33 and the other end connected to the ground (GND). Resistors R2 to R4 are connected in series to connection line L1.
The resistor R2 has one end connected to the sensor output terminal 33 and the other end connected to one end of the resistor R3. The other end of resistor R3 is connected to one end of resistor R4. The other end of resistor R4 is connected to input terminal 43 . The voltage follower circuit 100 is connected in parallel with the resistor R2.

The anode of the diode 101 is connected to the connection line L1 between the voltage follower circuit 100 and the microcomputer 4. More specifically, the anode of diode 101 is connected to connection line L1 between the other end of resistor R3 and one end of resistor R4.
A cathode of the diode 101 is connected to the first output terminal 51 of the first DC power supply 5 . This prevents overvoltage from being applied to the input terminal 43 in the write mode.

Next, the operation of the current detection device 1 according to this embodiment will be described.

The current detection device 1 is attached to, for example, a core passing through a busbar arranged in an inverter in a vehicle. When a current (a current to be measured) flows through the busbar, a magnetic field corresponding to the current value of the current is generated. The magnetoelectric conversion element 34 detects, via the core, the magnetic field and magnetic flux generated by the Hall IC 3 operating in the normal mode and the current to be measured flowing through the busbar. The magnetoelectric conversion element 34 converts the detected magnetic field or magnetic flux into a voltage signal. Here, the third voltage Vs generated by the voltage generator 7 is applied to the power supply terminal 31 . Therefore, the signal processing unit 35 operates in the normal mode, amplifies the voltage signal with the amplification factor G indicated by the amplification factor data stored in the memory of the signal processing unit 35, and the amplified voltage signal is A sensor signal is output from the sensor output terminal 33 to the microcomputer 4 . A first voltage Vcc is applied to a power supply terminal 41, and the microcomputer 4 operates with the first voltage Vcc as a drive source, converts the sensor signal into a digital signal, and obtains the current value of the current to be measured.

Here, both the Hall I3C and the AD converter of the microcomputer 4 have ratiometric characteristics. Therefore, the power supply voltage Vh of the Hall IC 3 and the power supply voltage Vm of the microcomputer 4 must always be at the same potential. This is because in the normal mode, unless the power supply voltage Vh of the hall IC 3 and the power supply voltage Vm of the microcomputer 4 are always at the same potential, an error will occur between the analog signal (sensor signal) and the digital signal. is. For example, when power supply voltage Vm fluctuates, power supply voltage Vh must also fluctuate.

In this embodiment, the voltage generator 7 generates the power supply voltage Vh, and the voltage value of the power supply voltage Vh is adjusted so that the voltage value of the power supply voltage Vh and the voltage value of the power supply voltage Vm are the same. is feedback controlled. Therefore, the current detection device 1 can suppress the error.

Next, a method of writing data to the Hall IC 3 (hereinafter simply referred to as "data writing method") will be described with reference to FIG. FIG. 4 is a diagram for explaining the flow of the data writing method according to this embodiment.

A user who adjusts the amplification factor G of the Hall IC 3 first connects the voltage follower circuit 100 in parallel to the connection line L1 (step S101: first connection step). Also, the user connects the connection line L1 between the voltage follower circuit 100 and the microcomputer 4 to the first output terminal 51 via a diode (step S102: second connection step).
Then, the user connects the output terminal of the voltage application section 90 to the power terminal 31 via the connection line L2 and operates the first operation section (not shown) of the output section 21 . As a result, the voltage application unit 90 applies the write voltage Vw to the power supply terminal 31 via the connection line L2, and shifts the Hall IC 3 from the normal mode to the write mode (step S103: application step).

Here, a write voltage Vw higher than the power supply voltage Vh is applied to the power supply terminal 31, but the power supply voltage Vm remains at 5V and does not fluctuate. This is because the power terminals 31 and 41 are not electrically connected. Therefore, even if a write voltage Vw (for example, 8V) higher than the power supply voltage Vh is applied to the power supply terminal 31, the voltage of the power supply terminal 41 remains at 5V, and the microcomputer 4 does not break down. Therefore, in adjusting the amplification factor G, the gain can be adjusted without removing the Hall IC 3 from the substrate, and the gain can be adjusted efficiently.

The user operates the second operation section (not shown) of the output section 21 when the Hall IC 3 is in the write mode. As a result, the writing unit 91 inputs the amplification factor data to the power supply terminal 31 by a pulse signal of the write voltage Vw or more via the connection line L2, and writes the setting of the amplification factor G to the memory of the Hall IC 3 (step S104: write step). This allows the user to adjust the amplification factor G to a desired value.
The first operation unit and the second operation unit may be switches such as buttons, or may be touch panels.

Although the embodiment of the present invention has been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and design and the like are included within the scope of the gist of the present invention.

Although the power supply terminal 31 also functions as an input terminal for inputting data to the Hall IC when the Hall IC 3 is in the write mode, it is not limited to this. A terminal other than the power supply terminal 31 (for example, the sensor output terminal 33) may function as an input terminal for inputting data (amplification factor data) to the Hall IC.

As described above, the current detection device 1 according to the present embodiment has the voltage generator 7 that generates the third voltage Vs, which is the power supply voltage of the Hall IC 3 , from the second voltage Vx and outputs the voltage to the Hall IC 3 . Then, the voltage generator 7 controls the voltage value of the third voltage Vs so that the voltage value of the third voltage Vs and the voltage value of the first voltage Vcc input to the first terminal 71 are the same. do.

With such a configuration, it is possible to control the power supply voltages of the Hall IC and the microcomputer so that they are always at the same potential during sensing (normal mode). Furthermore, even if a voltage higher than 5V is applied to the power terminal 31 of the Hall IC 3, the voltage of the power terminal 41 of the microcomputer 4 is not affected. Therefore, when adjusting the gain G, it is not necessary to remove the Hall IC 3 from the substrate, and the gain G can be adjusted while the Hall IC 3 is mounted on the substrate. Therefore, it is possible to efficiently adjust the gain of the Hall IC.

A Data writing system 1 Current detection device 2 Writing device 3 Hall IC
4 microcomputer 5 first DC power supply 6 second DC power supply 7 voltage generator 71 first terminal 72 second terminal 73 third terminal 75 voltage duplicator

Claims (5)

a magnetoelectric conversion element that detects a magnetic field or magnetic flux and converts it into a voltage signal; a Hall IC that outputs a sensor signal, which is a signal obtained by amplifying the voltage signal with a predetermined amplification factor, from a sensor output terminal;
a processor for converting the sensor signal into a digital signal;
a first DC power supply having a first output terminal, generating a first voltage that is a power supply voltage of the processing device and outputting the first voltage from the first output terminal to a power supply terminal of the processing device;
a second DC power supply having a second output terminal, generating a second voltage higher than the first voltage and outputting the second voltage from the second output terminal;
a voltage generator that generates a third voltage, which is a power supply voltage of the Hall IC, from the second voltage and outputs the third voltage to the Hall IC;
has
The voltage generator is
a first terminal connected to a power terminal of the processing device;
a second terminal connected to the second output terminal;
a third terminal connected to a power supply terminal of the Hall IC;
controlling the voltage value of the third voltage so that the voltage value of the third voltage and the voltage value of the first voltage input to the first terminal are the same, a voltage replicating unit outputting from the third terminal;
A current sensing device comprising: The Hall IC and the processing device are mounted on the same substrate,
The current detection device according to claim 1, characterized by: When a write voltage higher than the second voltage is applied to the power supply terminal of the Hall IC, the Hall IC shifts to a write mode in which data can be written to the Hall IC.
3. The current detection device according to claim 1 or 2, characterized in that: 4. The current detection device according to claim 3, wherein the method of writing data to the Hall IC comprises:
an application step of applying the write voltage to a power supply terminal of the Hall IC to shift the Hall IC to a write mode;
a write step of writing the setting of the amplification factor to the Hall IC by inputting data indicating the amplification factor to a power supply terminal of the Hall IC in a write mode;
data write method, including The Hall IC has a sensor output terminal for outputting the sensor signal,
a first connection step of connecting a voltage follower circuit in parallel to a connection line connecting the sensor output terminal and the processing device;
a second connection step of connecting the connection line between the voltage follower circuit and the processing device and the first output terminal via a diode;
including
The applying step is performed after the first connecting step and the second connecting step,
5. The data write method according to claim 4, wherein:

Images