Power Supply Control Circuit and Power Supply Circuit

• US 20120187931A1
• Filed: 07/27/2011
• Published: 07/26/2012
• Est. Priority Date: 07/29/2010
• Status: Abandoned Application

• Current Assignee: Semiconductor Components Industries LLC (ON Semiconductor Corporation)
• Original Assignee: ON Semiconductor Trading, Ltd (ON Semiconductor Corporation)
• Inventors: Maruki, Masahiro
• Application Number:
  US13/191,955
• Publication Number:
  US 20120187931A1
• Time in Patent Office: Days
• US Class Current: 323/282
• CPC Class Codes: H02M 3/156 with automatic control of output voltage or current, e.g. switching regulators

Abstract

A power supply control circuit comprising: a first control circuit configured to control on/off of a transistor, whose input electrode is applied with an input voltage, based on a feedback voltage so that an output voltage at a target level is generated from the input voltage to be applied to a load, the feedback voltage being in accordance with a reference voltage and the output voltage; and a second control circuit configured to control a feedback voltage generation circuit so that the output voltage rises with increase in load current flowing through the load, the feedback voltage generation circuit configured to generate the feedback voltage.

Claims

1. A power supply control circuit comprising:

a first control circuit configured to control on/off of a transistor, whose input electrode is applied with an input voltage, based on a feedback voltage so that an output voltage at a target level is generated from the input voltage to be applied to a load, the feedback voltage being in accordance with a reference voltage and the output voltage; and

a second control circuit configured to control a feedback voltage generation circuit so that the output voltage rises with increase in load current flowing through the load, the feedback voltage generation circuit configured to generate the feedback voltage.

2. The power supply control circuit according to claim 1, wherein

the second control circuit is configured to control the feedback voltage generation circuit so that the output voltage rises with increase in the load current based on a voltage generated in a detection resistor, the detection resistor disposed closer to the load as compared with a connection node between an inductor connected to an output electrode of the transistor and a capacitor connected to the inductor, the detection resistor configured to detect the load current.

3. A power supply circuit configured to generate an output voltage at a target level from an input voltage, comprising:

a transistor whose input electrode is applied with the input voltage;

an inductor having one end connected to an output electrode of the transistor;

a capacitor connected to the other end of the inductor, the capacitor configured to generate the output voltage at the target level;

a detection resistor having one end connected to the other end of the inductor, the detection resistor configured to detect a load current flowing through a load;

a feedback voltage generation circuit configured to generate a feedback voltage, the feedback voltage being in accordance with the output voltage;

a first control circuit configured to control on/off of the transistor so that the output voltage at the target level is generated from the input voltage based on a reference voltage and the feedback voltage; and

a second control circuit configured to control the feedback voltage generation circuit so that the output voltage rises with increase in the load current based on a voltage generated in the detection resistor.

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

the feedback voltage generation circuit includes a voltage dividing circuit configured to output a divided voltage as the feedback voltage, the divided voltage obtained by dividing the output voltage, and wherein

the second control circuit is configured to control a current flowing through the voltage dividing circuit so that the output voltage rises with increase in the load current based on the voltage generated in the detection resistor.

5. The power supply circuit according to claim 4, further comprising:

a resistor having one end connected to the one end of the detection resistor; and

a current generation circuit configured to generate a current flowing through the resistor, wherein

the second control circuit includes;

an operational amplifier configured to control the current generation circuit so that a voltage at the other end of the detection resistor becomes equal to a voltage at the other end of the resistor; and

a current control circuit configured to control the current flowing through the voltage dividing circuit so that the output voltage rises with increase in the current flowing through the resistor.