IP Library Granted Patent US 12671407
Granted Patent B2
US 12671407 · App. 18/885,982 · Granted Jun 30, 2026

Semiconductor device, electronic apparatus and vehicle

Inventors: Makoto Sada (Kyoto, JP); Katsuaki Yamada (Kyoto, JP); Shuntaro Takahashi (Kyoto, JP); Toru Takuma (Kyoto, JP); Naoki Takahashi (Kyoto, JP)
Assignee: Rohm Co., Ltd.
H03K17/0822H03K2217/0027H03K2217/0045H03K2217/0072
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Quick Facts
Patent No.
US 12671407
App. No.
18/885,982
Granted
Jun 30, 2026
Kind
B2
Abstract

The present disclosure provides a semiconductor device. The semiconductor device includes: a semiconductor substrate; a well, formed in the semiconductor substrate; an output terminal, electrically connected to the semiconductor substrate; a ground terminal, configured to receive a ground voltage; a detection signal generating circuit, configured to generate a negative current detection signal when an output voltage present at the output terminal is detected to be less than the ground voltage; and a control circuit, configured to apply the ground voltage or the output voltage to the well in response to the negative current detection signal. The detection signal generating circuit includes: a comparator, configured to generate the negative current detection signal by comparing an output detection voltage with the ground voltage or the threshold voltage; a bias circuit, configured to switch between applying the output voltage or a bias voltage as the output detection voltage; and a clamp circuit.

Claims (29)

1 . A semiconductor device, comprising:

a semiconductor substrate of a first conductivity type;

a well of a second conductivity type different from the first conductivity type, formed in the semiconductor substrate;

an output terminal, configured to be electrically connected to the semiconductor substrate;

a ground terminal, configured to receive a ground voltage;

a detection signal generating circuit, configured to generate a negative current detection signal when an output voltage present at the output terminal is detected to be less than the ground voltage or a threshold voltage; and

a control circuit, configured to switch between applying the ground voltage or the output voltage to the well in response to the negative current detection signal, wherein

the detection signal generating circuit includes:

a comparator, configured to generate the negative current detection signal by comparing an output detection voltage with the ground voltage or the threshold voltage;

a bias circuit, configured to switch between applying the output voltage or a bias voltage as the output detection voltage; and

a clamp circuit, configured to operate when an absolute value of the output detection voltage is greater than a clamp operation voltage.

2 . The semiconductor device of claim 1 , wherein the clamp circuit includes:

at least one first diode connected with a first polarity and between an application terminal of the output detection voltage and the ground terminal; and

at least one second diode connected with a second polarity opposite to the first polarity and between the application terminal of the output detection voltage and the ground terminal.

3 . The semiconductor device of claim 1 , wherein

the bias circuit includes a first transistor connected between the output terminal and an application terminal of the output detection voltage, and

the clamp operation voltage is greater than a differential voltage obtained by subtracting an on-threshold voltage of the first transistor from a voltage applied to a control terminal of the first transistor.

4 . The semiconductor device of claim 3 , wherein the bias circuit further includes a first resistor connected between a main electrode of the first transistor and the application terminal of the output detection voltage.

5 . The semiconductor device of claim 4 , wherein the bias circuit further includes a second resistor connected between the control terminal of the first transistor and an application terminal of a power supply voltage.

6 . The semiconductor device of claim 1 , further comprising:

a second transistor, configured to connect/disconnect the well to/from the ground terminal in response to the negative current detection signal; and

a third resistor, connected between the well and the ground terminal.

7 . The semiconductor device of claim 1 , further comprising a power transistor configured to be connected between the output terminal and the ground terminal.

8 . An electronic apparatus, comprising:

an inductive load;

a half-bridge or full-bridge switch output stage, configured to drive the load; and

the semiconductor device according to claim 1 , configured to function as a low-side switch element of the switch output stage or a driving means thereof.

9 . The electronic apparatus of claim 8 , wherein the inductive load includes a motor.

10 . A vehicle, comprising the electronic apparatus of claim 8 .