Magnetic sensor apparatus and current sensor apparatus

• US 10,436,856 B2
• Filed: 12/21/2016
• Issued: 10/08/2019
• Est. Priority Date: 12/24/2015
• Status: Active Grant

• Current Assignee: Asahi Kasei Microdevices Corporation (Asahi Kasei Corporation)
• Original Assignee: Asahi Kasei Microdevices Corporation (Asahi Kasei Corporation)
• Inventors: Nakamura, Takenobu, Aiba, Yuusuke
• Primary Examiner(s): Zakaria, Akm
• Application Number:
  US15/385,875
• Publication Number:
  US 20170184688A1
• Time in Patent Office: 1,021 Days
• CPC Class Codes: G01R 33/0041 using feed-back or modulation techniques
• CPC Class Codes: G01R 33/07 Hall effect devices

Abstract

A sensor apparatus adjusts output timings of a detection signal and a sensing signal for sensing an abnormality in the detection signal. Provided is a magnetic sensor apparatus comprising a magnetic sensor element, an amplifying section that amplifies and outputs an output of the magnetic sensor element, a plurality of comparing sections that compare the output of the magnetic sensor element or an output of the amplifying section to a threshold value, and a plurality of delaying sections that each delay and output a comparison result output by a corresponding comparing section among the plurality of comparing sections. Also provided is a current sensor apparatus including a current path through which a current serving as a measurement target flows and a magnetic sensor apparatus that is arranged corresponding to the current path and detects a magnetic field generated according to the current serving as the measurement target.

Claims

1. A current sensor apparatus comprising:

a current path through which a current serving as a measurement target flows;

a magnetic sensor apparatus that is arranged corresponding to the current path and detects a magnetic field generated according to the current serving as the measurement target, the magnetic sensor apparatus comprising;

a magnetic sensor element;

an amplifying section that amplifies and outputs an output of the magnetic sensor element; and

a plurality of detecting sections,

a threshold value generating circuit that generates an upper threshold value and a lower threshold value,

wherein each of the plurality of detecting sections includes;

a set of (i) a comparing section that compares the output of the magnetic sensor element or an output of the amplifying section to a threshold value and (ii) a delaying section that delays and outputs a comparison result output by the comparing section, and

the comparing section of a first detecting section compares the output of the magnetic sensor element or the output of the amplifying section to a first threshold value,

the comparing section of a second detecting section compares the output of the magnetic sensor element or the output of the amplifying section to a second threshold value that differs from the first threshold value, and

the delaying section of the first detecting section has a different delay amount than the delaying section of the second detecting section,

wherein the comparing section of each detecting section includes;

a first comparing circuit that compares the output of the magnetic sensor element or the output of the amplifying section to the upper threshold value,

a second comparing circuit that compares the output of the magnetic sensor element or the output of the amplifying section to the lower threshold value, and a logic circuit that is connected to the first comparing circuit and the second comparing circuit, and outputs a signal indicating whether the output of the magnetic sensor element or the output of the amplifying section exceeds the upper threshold value and whether the output of the magnetic sensor element or the output of the amplifying section is below the lower threshold value based on an output of the first comparing circuit and an output of the second comparing circuit, and

wherein the magnetic sensor apparatus is implemented in a package that includes a first output terminal outputting an output signal of the amplifying section as a first output that is a magnetic field detection signal corresponding to a magnitude of the generated magnetic field, and one or more second output terminals that each output an output signal of a delaying section among the plurality of delaying sections as a second output that is a sensing signal that when the generated magnetic field is outside of a reference range provides notification to a control apparatus that detects an abnormality based on the sensing signal.

2. The current sensor apparatus according to claim 1, wherein

each delaying section includes a variable delay circuit and

the magnetic sensor apparatus further comprises a setting section that sets a delay amount of each variable delay circuit, according to instructions from outside.

3. The current sensor apparatus according to claim 2, wherein

each delaying section further includes a glitch filter that removes a glitch in the comparison result output by a corresponding comparing section, and

each variable delay circuit delays and outputs the comparison result that has passed through a corresponding glitch filter.

4. The current sensor apparatus according to claim 1, wherein

the magnetic sensor element is a Hall element that has a first terminal pair and a second terminal pair, and

the amplifying section includes a switching section that switches a terminal pair causing a drive current to flow and a terminal pair that senses the output of the magnetic sensor element, between the first terminal pair and the second terminal pair of the magnetic sensor element, according to a first clock supplied from outside.

5. The current sensor apparatus according to claim 4, further comprising:

a clock generating section that generates a second clock, which has a frequency that is an integer multiple of a frequency of the first clock and a predetermined phase difference relative to a timing of the first clock.

6. The current sensor apparatus according to claim 5, wherein

each comparing section compares the output of the magnetic sensor element or the output of the amplifying section to the threshold value, according to the second clock.

7. The current sensor apparatus according to claim 5, wherein

each delaying section delays the comparison result output by the corresponding comparing section, according to the second clock.

8. The current sensor apparatus according to claim 1, further comprising:

one or more integrating sections that each integrate the comparison result output by a corresponding comparing section or the delayed comparison result output by a corresponding delaying section; and

one or more integration notifying sections that correspond to the one or more integrating sections and each notify to outside that an integration result of the corresponding integrating section is outside a reference range.

9. The current sensor apparatus according to claim 1, wherein

the amplifying section amplifies the output of the magnetic sensor element, converts the amplified output into a digital signal, and outputs the digital signal, and

the magnetic sensor apparatus further comprises one or more first malfunction judging sections that each determine there is a malfunction in response to the digital signal not being a value corresponding to a logical value of the comparison result output by a corresponding comparing section or the delayed comparison result output by a corresponding delaying section.

10. The current sensor apparatus according to claim 1, wherein

the first threshold value includes a first upper threshold value and a first lower threshold value indicating a predetermined first output range of the magnetic sensor element, and

the second threshold value includes a second upper threshold value that is smaller than the first upper threshold value and a second lower threshold value that is larger than the first lower threshold value indicating a predetermined second output range of the magnetic sensor element.

11. The current sensor apparatus according to claim 1, wherein

the delaying section of the first detecting section among the plurality of detecting sections has a smaller delay amount than the delaying section of the second detecting section among the plurality of detecting sections.

12. The current sensor apparatus according to claim 1, wherein

the amplifying section further includes a delay circuit that delays the output of the magnetic sensor element, and

the comparing section of the second detecting section among the plurality of detecting sections compares an output of the delay circuit to the second threshold value.

13. The current sensor apparatus according to claim 12, wherein

the delay circuit includes a filter that reduces noise.

14. The current sensor apparatus according to claim 1, further comprising:

a second malfunction judging section that judges whether there is a malfunction according to a result obtained by comparing the comparison result output by the comparing section or the delayed comparison result output by the delaying section in the first detecting section among the plurality of detecting sections to the comparison result output by the comparing section or the delayed comparison result output by the delaying section in the second detecting section among the plurality of detecting sections.

15. The current sensor apparatus according to claim 1, wherein the threshold value generating circuit includes at least one variable resistor.

16. The current sensor apparatus according to claim 1, wherein the threshold value generating circuit includes:

a first resistor whose one end is connected to a power supply voltage;

a first variable resistor whose one end is connected to another end of the first resistor with a first connecting point; and

a second resistor whose one end is connected to another end of the first variable resistor with a second connecting point, and whose another end is connected to a reference potential, wherein

the first connecting point outputs the upper threshold value, and

the second connecting point outputs the lower threshold value.

17. The current sensor apparatus according to claim 1, wherein the threshold value generating circuit includes:

a first resistor whose one end is connected to a power supply voltage;

a second resistor whose one end is connected to another end of the first resistor with a first connecting point; and

a third resistor whose one end is connected to another end of the second resistor with a second connecting point, and whose another end is connected to a reference potential, wherein

at least two resistors among the first resistor, the second resistor, and the third resistor have a variable resistance,

the first connecting point outputs the upper threshold value, and

the second connecting point outputs the lower threshold value.

18. The current sensor apparatus according to claim 1, wherein the logic circuit outputs a logical sum of the output of the first comparing circuit and the output of the second comparing circuit.

19. The current sensor apparatus according to claim 1, wherein the first comparing circuit and the second comparing circuit are comparators.

20. The current sensor apparatus according to claim 10, wherein the first upper threshold value and the second upper threshold value are greater than V_DD/2 and less than V_DD, and the first lower threshold value and the second lower threshold value are greater than V_SS and less than V_DD/2, in which V_DD is a power supply potential, and V_SS is a reference potential.

21. A system comprising:

the current sensor apparatus according to claim 1; and

the control apparatus according to claim 1.