POWER SUPPLY CIRCUIT

• US 20190305686A1
• Filed: 03/25/2019
• Published: 10/03/2019
• Est. Priority Date: 03/30/2018
• Status: Active Grant

• Current Assignee: Ablic Inc. (MinebeaMitsumi Inc.)
• Original Assignee: Ablic Inc. (MinebeaMitsumi Inc.)
• Inventors: WATANABE, Kotaro
• Granted Patent: US 10,454,376 B1
• Time in Patent Office: Days
• CPC Class Codes: H02M 1/0003 Details of control, feedback or regulation circuits
• CPC Class Codes: H02M 1/0045 Converters combining the concepts of switch-mode regulation and linear regulation, e.g. linear pre-regulator to switching converter, linear and switching converter in parallel, same converter or same transistor operating either in linear or switching mode
• CPC Class Codes: H02M 1/0048 Circuits or arrangements for reducing losses using snubbers H02M1/34
• CPC Class Codes: H02M 1/0067 Converter structures employing plural converter units, other than for parallel operation of the units on a single load
• CPC Class Codes: H02M 1/10 Arrangements incorporating converting means for enabling loads to be operated at will from different kinds of power supplies, e.g. from ac or dc
• CPC Class Codes: H02M 3/07 using capacitors charged and discharged alternately by semiconductor devices with control electrode , e.g. charge pumps
• CPC Class Codes: H02M 3/157 with digital control
• CPC Class Codes: H02M 3/1584 with a plurality of power processing stages connected in parallel
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Abstract

Provided is a power supply circuit including a series regulator step-down power circuit, a charge pump step-up power circuit, and a voltage selection circuit to which a voltage of an input terminal and a voltage of an output terminal are supplied and configured to output a higher voltage from the supplied voltages. A connection point of a first resistor and a second resistor which are connected between the output terminal and a ground terminal is connected to an input of a differential amplifier circuit. An output of the differential amplifier circuit is connected to a gate terminal of an output transistor via a first switch. An output of the voltage selection circuit is connected to the gate terminal of the output transistor via a second switch. The output of the voltage selection circuit is connected to a substrate electrode of the output transistor.

Claims

1. A power supply circuit, comprising:

an input terminal;

an output terminal;

a ground terminal;

a series regulator step-down power circuit having an input connected to the input terminal and an output connected to the output terminal and including a P-channel MOSFET serving as an output transistor, a differential amplifier circuit, a first resistor, a second resistor, a first switch, and a second switch;

a charge pump step-up power circuit having an input connected to the input terminal and an output connected to the output terminal; and

a voltage selection circuit to which a voltage of the input terminal and a voltage of the output terminal are supplied and configured to output a higher voltage of the voltage of the input terminal and the voltage of the output terminal,

the first resistor and the second resistor being connected in series between the output terminal and the ground terminal;

a connection point of the first resistor and the second resistor being connected to an input of the differential amplifier circuit;

an output of the differential amplifier circuit being connected to a gate terminal of the output transistor via the first switch;

an output of the voltage selection circuit being connected to the gate terminal of the output transistor via the second switch; and

the output of the voltage selection circuit being connected to a substrate electrode of the output transistor.

2. A power supply circuit, comprising:

an input terminal;

an output terminal;

a ground terminal;

a series regulator step-down power circuit having an input connected to the input terminal and an output connected to the output terminal and including an N-channel MOSFET serving as an output transistor, a differential amplifier circuit, a first resistor, a second resistor, a first switch, and a second switch; and

a charge pump step-up power circuit having an input connected to the input terminal and an output connected to the output terminal,

the first resistor and the second resistor being connected in series between the output terminal and the ground terminal;

a connection point of the first resistor and the second resistor being connected to an input of the differential amplifier circuit;

an output of the differential amplifier circuit being connected to a gate terminal of the output transistor via the first switch;

the ground terminal being connected to the gate terminal of the output transistor via the second switch; and

the ground terminal being connected to a substrate electrode terminal of the output transistor.