Power Supply Control Circuit and Power Supply Circuit
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.
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.