Semiconductor integrated circuit for regulator

Patent metadata

Field	Value
Publication number	US-10466728-B2
Application number	US-201816186099-A
Country	US
Kind code	B2
Filing date	Nov 9, 2018
Priority date	Nov 10, 2017
Publication date	Nov 5, 2019
Grant date	Nov 5, 2019

Abstract

A semiconductor integrated circuit for a regulator includes an output controlling transistor, a controller circuit, a breeder resister and a current limiting resistor. The output controlling transistor is connected between an output terminal and a voltage input terminal. The breeder resister is connected between the output terminal and a constant potential point and generates the feedback voltage. The current limiting resistor is connected with the breeder resistor between the output terminal and the constant potential point.

First claim

What is claimed is:

1. A semiconductor integrated circuit for a regulator, comprising:
an output controlling transistor which comprises a bipolar transistor connected between an output terminal and a voltage input terminal to which a DC voltage is input;
a controller circuit which controls the output controlling transistor according to a feedback voltage of an output voltage;
a breeder resistor which is connected between the output terminal and a constant potential point and which generates the feedback voltage by dividing the output voltage; and
a current limiting resistor which is connected in series with the breeder resistor between the output terminal and the constant potential point,
wherein:
the breeder resistor comprises a first diffusion layer which is formed in a surface of a first semiconductor island region on a semiconductor substrate, the first semiconductor island region being surrounded by a first isolation region,
the current limiting resistor comprises a second diffusion layer which is formed in a surface of a second semiconductor island region surrounded by a second isolation region, the second semiconductor island region being different from the first semiconductor island region,
the current limiting resistor has a resistance that prevents a potential difference across the current limiting resistor at a current in a normal operating state from exceeding a forward voltage of a base diode parasitic to the current limiting resistor, and
the first and second diffusion layers have a same conductivity type and are formed in surfaces of first and second island regions of an epitaxial layer that are electrically insulated from each other.

2. The semiconductor integrated circuit for a regulator according to claim 1 , wherein the controller circuit comprises a vertical bipolar transistor which includes:
a first buried layer of a first conductivity type which is formed as a collector region in the semiconductor substrate;
a third diffusion layer of a second conductivity type which is formed as a base region in a surface of a semiconductor island region of the epitaxial layer above the first buried layer; and
a fourth diffusion layer of the first conductivity type which is formed as an emitter region inside the base region.

3. The semiconductor integrated circuit for a regulator according to claim 1 , wherein the bipolar transistor of the output controlling transistor is a horizontal bipolar transistor or a vertical bipolar transistor including a second buried layer of a second conductivity type.

4. A semiconductor integrated circuit for a regulator comprising:
an output controlling transistor which comprises a bipolar transistor connected between an output terminal and a voltage input terminal to which a DC voltage is input;
a controller circuit which controls the output controlling transistor according to a feedback voltage of an output voltage;
a breeder resistor which is connected between the output terminal and a constant potential point and which generates the feedback voltage by dividing the output voltage; and
a current limiting resistor which is connected in series with the breeder resistor between the output terminal and the constant potential point,
wherein:
the breeder resistor comprises a first diffusion layer which is formed in a surface of a first semiconductor island region on a semiconductor substrate, the first semiconductor island region being surrounded by a first isolation region,
the current limiting resistor comprises a second diffusion layer which is formed in a surface of a second semiconductor island region surrounded by a second isolation region, the second semiconductor island region being different from the first semiconductor island region,
the current limiting resistor is connected between the output terminal and an island electrode of the first semiconductor island region including the breeder resistor, and
the first and second diffusion layers have a same conductivity type and are formed in surfaces of first and second island regions of an epitaxial layer that are electrically insulated from each other.

5. The semiconductor integrated circuit for a regulator according to claim 4 , wherein the controller circuit comprises a vertical bipolar transistor which includes:
a first buried layer of a first conductivity type which is formed as a collector region in the semiconductor substrate;
a third diffusion layer of a second conductivity type which is formed as a base region in a surface of a semiconductor island region of the epitaxial layer above the first buried layer; and
a fourth diffusion layer of the first conductivity type which is formed as an emitter region inside the base region.

6. The semiconductor integrated circuit for a regulator according to claim 4 , wherein the bipolar transistor of the output controlling transistor is a horizontal bipolar transistor or a vertical bipolar transistor including a second buried layer of a second conductivity type.

7. A semiconductor integrated circuit for a regulator comprising:
an output controlling transistor which comprises a bipolar transistor connected between an output terminal and a voltage input terminal to which a DC voltage is input;
a controller circuit which controls the output controlling transistor according to a feedback voltage of an output voltage;
a breeder resistor which is connected between the output terminal and a constant potential point and which generates the feedback voltage by dividing the output voltage; and
a current limiting resistor which is connected in series with the breeder resistor between the output terminal and the constant potential point,
wherein:
the breeder resistor comprises a first diffusion layer which is formed in a surface of a first semiconductor island region on a semiconductor substrate, the first semiconductor island region being surrounded by a first isolation region,
the current limiting resistor comprises a second diffusion layer which is formed in a surface of a second semiconductor island region surrounded by a second isolation region, the second semiconductor island region being different from the first semiconductor island region,
the current limiting resistor is connected between the output terminal and an island electrode of the first semiconductor island region including the breeder resistor, and
the bipolar transistor of the output controlling transistor is a horizontal bipolar transistor or a vertical bipolar transistor including a second buried layer of a second conductivity type.

8. The semiconductor integrated circuit for a regulator according to claim 7 , wherein the controller circuit comprises a vertical bipolar transistor which includes:
a first buried layer of a first conductivity type which is formed as a collector region in the semiconductor substrate;
a third diffusion layer of the second conductivity type which is formed as a base region in a surface of a semiconductor island region of an epitaxial layer above the first buried layer; and
a fourth diffusion layer of the first conductivity type which is formed as an emitter region inside the base region.

Assignees

• Maki Shinichiro
• Takano Yoichi
• Yokoyama Katsuhiro
• Mitsumi Electric Co Ltd

Inventors

• Maki Shinichiro
• Takano Yoichi
• Yokoyama Katsuhiro

Classifications

• H02H9/046

  responsive to excess voltage appearing at terminals of integrated circuits · CPC title

• G05F1/573

  with overcurrent detector · CPC title

• G05F1/575 Primary

  characterised by the feedback circuit · CPC title

• H02H9/02

  responsive to excess current {(current limitation for voltage regulators G05F1/573; disconnection after limiting H02H3/025)} · CPC title

• H01L27/0259

  Electricity · mapped topic