Power supply device and electronic control unit for lowering a minimum operating voltage and suppressing a consumed current to be low

• US 10,268,221 B2
• Filed: 02/20/2017
• Issued: 04/23/2019
• Est. Priority Date: 05/12/2016
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Satake, Hiroyuki, Uemura, Shinya, Mikami, Yuki
• Primary Examiner(s): Torres-Rivera, Alex
• Application Number:
  US15/780,361
• Publication Number:
  US 20180348804A1
• Time in Patent Office: 792 Days
• Field of Search: 323226, 323269, 323270, 323273-281, 323303
• CPC Class Codes: G05F 1/56 using semiconductor devices in series with the load as final control devices G05F1/461 takes precedence
• CPC Class Codes: H02J 2207/20 Charging or discharging characterised by the power electronics converter
• CPC Class Codes: H02M 1/0032 Control circuits allowing low power mode operation, e.g. in standby mode
• 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 1/0054 Transistor switching losses periodically suspending operation of switching converter in low power mode H02M1/0035
• CPC Class Codes: H02M 1/36 Means for starting or stopping converters
• CPC Class Codes: H02M 3/156 with automatic control of output voltage or current, e.g. switching regulators
• CPC Class Codes: H02M 3/158 including plural semiconductor devices as final control devices for a single load
• 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

A power supply device comprises: a first linear regulator, which receives a voltage from a direct-current power supply at all times and outputs a first voltage; a step-down switching regulator, which receives the voltage from the direct-current power supply through a path via a power supply switch and outputs an intermediate voltage, and a second linear regulator, which receives the intermediate voltage and outputs a second voltage. The power supply device outputs a higher one of the first voltage and the second voltage. The first linear regulator has a smaller current consumption and a higher minimum operating voltage than the second linear regulator. When the voltage supplied from the direct-current power supply is lower than or equal to a predetermined threshold value, the switching regulator drives a main switching component interposed in series with a voltage input-output path to turn on at all times. The second linear regulator executes an output operation of the second voltage during a full-on period, during which the main switching component is driven to turn on at all times.

Claims

1. A power supply device comprising:

a first linear regulator for receiving a voltage from a direct-current power supply at all times and outputting a first voltage;

a switching regulator of a step-down type for receiving the voltage from the direct-current power supply through a path via a power supply switch and outputting an intermediate voltage; and

a second linear regulator for receiving the intermediate voltage and outputting a second voltage, wherein;

the power supply device is configured to output a higher one of the first voltage and the second voltage through an output terminal;

the first linear regulator is configured to have a smaller consumption current and a higher minimum operating voltage than those of the second linear regulator;

the switching regulator is configured to drive a main switching element, which is interposed in series with a voltage input-output path of the switching regulator, to turn on at all times, when the voltage supplied from the direct-current power supply is equal to or lower than a predetermined value;

the second linear regulator executes an outputting operation of the second voltage during a full-on period, in which the main switching element of the switching regulator is turned on at all times.

2. The power supply device according to claim 1, wherein:

the first linear regulator is formed of an N-channel type MOS transistor or an NPN type bipolar transistor as a voltage control switching element, which is interposed in series with a voltage input-output path of the first linear regulator; and

the second linear regulator is formed of a P-channel type MOS transistor or a PNP type bipolar transistor as the voltage control switching element.

3. The power supply device according to claim 1, wherein:

each of the first linear regulator and the second linear regulator includes a reverse-flow blocking MOS transistor, which is interposed in series with the voltage input-output path.

4. The power supply device according to claim 1, wherein:

the first linear regulator includes a first reference voltage supply for generating a first reference voltage, which corresponds to a target value of the first voltage; and

the first reference voltage supply is configured to operate by receiving a voltage of the output terminal.

5. The power supply device according to claim 1, wherein:

the second linear regulator includes a second reference voltage supply for generating a second reference voltage, which corresponds to a target value of the second voltage; and

the second reference voltage supply is configured to operate by receiving the intermediate voltage.

6. The power supply device according to claim 1, wherein:

the second linear regulator includes a second reference voltage supply for generating a second reference voltage, which corresponds to a target value of the second voltage; and

the second reference voltage supply is configured to operate by receiving a voltage of the output terminal.

7. The power supply device according to claim 1, wherein:

the second linear regulator includes a power supply voltage detection part for detecting a voltage of the direct-current power supply and checks whether a detection result of the power supply voltage detection part indicates the full-on period of the main switching component.

8. The power supply device according to claim 1, wherein:

the direct current power supply is a battery mounted in a vehicle; and

the power supply switch is turned on and off in conjunction with an ignition switch of the vehicle.

9. The power supply device according to claim 8, wherein:

the first linear regulator includes a first reference voltage supply for generating a first reference voltage, which corresponds to a target value of the first voltage;

the first reference voltage supply is configured to operate by receiving a voltage of the output terminal;

the second linear regulator includes a second reference voltage supply for generating a second reference voltage, which corresponds to a target value of the second voltage;

the second reference voltage supply is configured to operate by receiving the intermediate voltage or a voltage of the output terminal; and

the second linear regulator includes a power supply voltage detection part for detecting a voltage of the direct-current power supply and checks whether a detection result of the power supply voltage detection part indicates the full-on period of the main switching component.

10. An electronic control unit comprising:

the power supply device according to claim 1; and

a control part for executing predetermined control by receiving power from the power supply.