# US 12,181,946 B2 · Abnormality detection circuit, semiconductor device, electronic apparatus, and vehicle

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- Number: US 12,181,946 B2
- Document ID: US12181946B2
- Status: Granted
- Kind: B2
- Application number: 18/149,741
- Filed: 2023-01-04
- Published: 2023-08-24
- Granted: 2024-12-31
- Earliest claimed: 2022-02-21
- Assignees: Rohm Co., Ltd.
- Applicants: Rohm Co., Ltd.
- Inventors: Keita Okamoto; Shojiro Kato
- Web page: https://patentgrep.com/patent/US12181946B2

## CPC

- G01R 31/52: Testing for short-circuits, leakage current or ground faults
- G06F 1/3206: Monitoring of events, devices or parameters that trigger a change in power modality
- G01R 31/3275: {Fault detection or status indication}
- G06F 1/3296: by lowering the supply or operating voltage
- G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12)
- G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N)

## Abstract

An abnormality detection circuit includes: a first current source configured to generate a first current flowing from an external terminal toward a reference potential terminal; a second current source configured to generate a second current flowing from a power supply potential terminal toward the external terminal; a comparator configured to generate an abnormality detection signal by comparing a detection voltage corresponding to an application voltage of the external terminal with a predetermined threshold voltage; and a controller configured to switch between a first abnormality detection mode in which an operation of generating the first current is performed and a second abnormality detection mode in which an operation of generating the second current is performed.

## Claims

### Claim 1

An abnormality detection circuit comprising:
a first current source configured to generate a first current flowing from an external terminal toward a reference potential terminal;
a second current source configured to generate a second current flowing from a power supply potential terminal toward the external terminal;
a comparator configured to generate an abnormality detection signal by comparing a detection voltage corresponding to an application voltage of the external terminal with a predetermined threshold voltage;
a first switch configured to electrically connect and disconnect between the first current source and the external terminal;
a second switch configured to electrically connect and disconnect between the second current source and the external terminal; and
a controller configured to switch between a first abnormality detection mode in which an operation of generating the first current is performed and a second abnormality detection mode in which an operation of generating the second current is performed,
wherein the controller is further configured to turn the first switch on and turn the second switch off in the first abnormality detection mode, and turn the first switch off and turn the second switch on in the second abnormality detection mode.

### Claim 2 (depends on 1)

The abnormality detection circuit of claim 1, wherein the threshold voltage is switched between the first abnormality detection mode and the second abnormality detection mode.

### Claim 3 (depends on 1)

The abnormality detection circuit of claim 1, further comprising a current mirror circuit configured to generate the first current and the second current from a common reference current.

### Claim 4 (depends on 1)

The abnormality detection circuit of claim 1, further comprising a third switch configured to electrically connect and disconnect between the external terminal and the first switch and between the external terminal and the second switch.

### Claim 5 (depends on 4)

A semiconductor device comprising:
the external terminal;
the abnormality detection circuit of claim 4; and
an output switch element configured to electrically connect and disconnect between the external terminal and the reference potential terminal or between the external terminal and the power supply potential terminal.

### Claim 6 (depends on 5)

The semiconductor device of claim 5, wherein the abnormality detection circuit is configured to sequentially perform an abnormality detection operation in the first abnormality detection mode and an abnormality detection operation in the second abnormality detection mode, and turn the output switch element on when no abnormality is detected.

### Claim 7 (depends on 5)

An electronic apparatus comprising:
the semiconductor device of claim 5; and
a load externally connected to the external terminal.

### Claim 8 (depends on 7)

A vehicle comprising the electronic apparatus of claim 7.