POWER SUPPLY SYSTEM

• US 20160225559A1
• Filed: 11/19/2015
• Published: 08/04/2016
• Est. Priority Date: 01/29/2015
• Status: Abandoned Application

• Current Assignee: Renesas Electronics Corporation
• Original Assignee: Renesas Electronics Corporation
• Inventors: UEKI, Takanori
• Application Number:
  US14/946,628
• Publication Number:
  US 20160225559A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 1/26 Power supply means, e.g. regulation thereof for memories G11C
• CPC Class Codes: G06F 1/266 Arrangements to supply power to external peripherals either directly from the computer or under computer control, e.g. supply of power through the communication port, computer controlled power-strips

Abstract

A power supply system according to an embodiment includes a USB connector and performs a power supply operation from a power supply circuit via the USB connector. A power supply apparatus includes a first power supply line of the power supply circuit that outputs a plurality of power supply voltages, a plurality of constant voltage diodes that each have breakdown voltages corresponding to the plurality of power supply voltages, and a control circuit that selects one of the plurality of power supply voltages as a power supply voltage which will be output from the power supply circuit and selects the constant voltage diode which will be connected to the first power supply line from among the plurality of constant voltage diodes.

Claims

1. A power supply system including a USB interface for performing a power supply operation from a power supply circuit via the USB interface, the power supply system comprising:

a first power supply line of the power supply circuit that outputs a plurality of power supply voltages;

a plurality of constant voltage diodes that each have breakdown voltages corresponding to the plurality of power supply voltages; and

a control circuit that selects one of the plurality of power supply voltages as a power supply voltage which will be output from the power supply circuit and selects one of the plurality of constant voltage diodes which will be connected to the first power supply line according to the selected power supply voltage.

2. The power supply system according to claim 1, wherein the control circuit performs a power delivery signal communication for selecting one of the plurality of power supply voltages according to a USB device that is connected to the USB interface using the first power supply line.

3. The power supply system according to claim 1, further comprising a connection detection unit that detects whether or not the USB device is connected to the USB interface, wherein

a state in which the control circuit is connected to the first power supply line and a state in which the constant voltage diode is connected to the first power supply line is switched based on a detection signal from the connection detection unit.

4. The power supply system according to claim 3, wherein

the constant voltage diode is connected to the first power supply line at the time of an insertion of the USB device into the USB interface and a removal of the USB device from the USB interface, and

the control circuit is connected to the first power supply line when the USB interface is connected to the USB device.

5. The power supply system according to claim 3, wherein

when the USB device is inserted into the USB interface, the constant voltage diode having the breakdown voltage corresponding to a power supply voltage that is the smallest among the plurality of power supply voltages is connected to the first power supply line, and

when the USB device is removed from the USB interface, the constant voltage diode having the breakdown voltage corresponding to the power supply voltage that has been selected according to the USB device is connected to the first power supply line.

6. The power supply system according to claim 1, wherein

the plurality of constant voltage diodes are connected in parallel via switches, respectively, between the first power supply line and a second power supply line, and

the control circuit controls the switches so as to select the constant voltage diode which will be connected to the first power supply line.

7. The power supply system according to claim 1, wherein

the plurality of constant voltage diodes are connected in series between the first power supply line and the second power supply line,

the power supply system includes a plurality of switches that are connected to the plurality of constant voltage diodes, respectively, and

the control circuit controls the switches so as to select the constant voltage diode which will be connected to the first power supply line.