Semiconductor integrated circuit for regulator

Patent metadata

Field	Value
Publication number	US-10063135-B2
Application number	US-201715721364-A
Country	US
Kind code	B2
Filing date	Sep 29, 2017
Priority date	Sep 30, 2016
Publication date	Aug 28, 2018
Grant date	Aug 28, 2018

Abstract

A semiconductor integrated circuit for a regulator includes an opening error detecting circuit detecting an opened state of an output terminal; a short-circuiting error detecting circuit detecting a short-circuiting state thereof; a first output terminal outputting a result detected by the opening error detecting circuit to an external unit; a second output terminal outputting a result detected by the short-circuiting error detecting circuit thereto; and a thermal shutdown circuit detecting the temperature of a semiconductor substrate and turns off the voltage control transistor if the detected temperature of the semiconductor substrate exceeds a predetermined temperature. A signal indicating the logic sum of an output signal of the thermal shutdown circuit and that of the short-circuiting error detecting circuit is outputted from the second output terminal such that the output signal of the opening error detecting circuit is not blocked based on the output signal of the thermal shutdown circuit.

First claim

What is claimed is:

1. A semiconductor integrated circuit for a regulator, comprising:
a voltage control transistor connected to both a voltage input terminal receiving a DC voltage and a voltage output terminal;
a control circuit controlling the voltage control transistor in response to a feedback voltage of an output;
an opening error detecting circuit detecting an opened state of the voltage output terminal;
a short-circuiting error detecting circuit detecting a short-circuiting state of the voltage output terminal;
a first output terminal outputting a result detected by the opening error detecting circuit to an external unit;
a second output terminal outputting a result detected by the short-circuiting error detecting circuit to the external unit; and
a thermal shutdown circuit detecting the temperature of a semiconductor substrate including the semiconductor integrated circuit disposed thereon and allowing the control circuit to turn off the voltage control transistor if the detected temperature of the semiconductor substrate exceeds a predetermined temperature,
wherein a signal indicating the logic sum of an output signal of the thermal shutdown circuit and an output signal of the short-circuiting error detecting circuit is outputted from the second output terminal such that the output signal of the opening error detecting circuit is not blocked based on the output signal of the thermal shutdown circuit.

2. The semiconductor integrated circuit for a regulator according to claim 1 , comprising:
a first transistor and a second transistor disposed in parallel with the voltage control transistor, a current scaled down in proportion to a current flowing in the voltage control transistor flowing in the first transistor and the second transistor, wherein,
the opening error detecting circuit comprises a first voltage comparing circuit comparing in magnitude the voltage converted from the current flowing in the first transistor with a predetermined comparative voltage,
the short-circuiting error detecting circuit comprises a second voltage comparing circuit comparing in magnitude the voltage converted from the current flowing in the second transistor with a predetermined comparative voltage, and
if a current having a value smaller than the value of a predetermined opening error detection current flows in the first transistor, the output signal of the first voltage comparing circuit is inverted, and if a current having a value larger than the value of a predetermined short-circuiting error detection current flows in the second transistor, the output signal of the second voltage comparing circuit is inverted.

3. The semiconductor integrated circuit for a regulator according to claim 2 , comprising:
a delay circuit delaying the output of at least the second voltage comparing circuit among the first voltage comparing circuit and the second voltage comparing circuit,
wherein a signal indicating the logic product of the output signal of the second voltage comparing circuit and the signal delayed by the delay circuit is outputted from the second output terminal as a short-circuiting error detection signal.

4. The semiconductor integrated circuit for a regulator, according to claim 2 , comprising:
a first external terminal connected to a first current-to-voltage transducer for converting the current flowing in the first transistor to a voltage; and
a second external terminal connected to a second current-to-voltage transducer for converting the current flowing in the second transistor to a voltage, wherein,
the first voltage comparing circuit compares the voltage converted by the first current-to-voltage transducer connected to the first external terminal with a predetermined comparative voltage, and
the second voltage comparing circuit compares the voltage converted by the second current-to-voltage transducer connected to the second external terminal with a predetermined comparative voltage.

5. The semiconductor integrated circuit for a regulator, according to claim 3 , comprising:
a first external terminal connected to a first current-to-voltage transducer for converting the current flowing in the first transistor to a voltage; and
a second external terminal connected to a second current-to-voltage transducer for converting the current flowing in the second transistor to a voltage, wherein,
the first voltage comparing circuit compares the voltage converted by the first current-to-voltage transducer connected to the first external terminal with a predetermined comparative voltage, and
the second voltage comparing circuit compares the voltage converted by the second current-to-voltage transducer connected to the second external terminal with a predetermined comparative voltage.

Assignees

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

Inventors

• Maki Shinichiro
• Takano Yoichi
• Yokoyama Katsuhiro

Classifications

• H02M3/156

  with automatic control of output voltage or current, e.g. switching regulators · CPC title

• H03K17/08

  Modifications for protecting switching circuit against overcurrent or overvoltage · CPC title

• H02M1/32 Primary

  Means for protecting converters other than automatic disconnection · CPC title

• G05F1/56 Primary

  using semiconductor devices in series with the load as final control devices (G05F1/461 takes precedence) · CPC title

• H02M3/158

  including plural semiconductor devices as final control devices for a single load · CPC title