Power supply circuit and power supply device
AssigneeRohm Co., Ltd.
InventorHiroki Inoue
Life of this patent
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Abstract
A power supply circuit according to the present invention includes, for example, an output circuit arranged to generate a stabilized voltage from an input voltage using an output transistor, a filter circuit arranged to smooth the stabilized voltage using a resistor and a capacitor so as to generate an output voltage, and a charging circuit arranged to supply charging current to the capacitor without the charging current being passed through the resistor.
Claims21
A power supply circuit comprising:
- an output circuit arranged to generate a stabilized voltage from an input voltage using an output transistor;
- a filter circuit arranged to smooth the stabilized voltage using a resistor and a capacitor so as to generate an output voltage;
- and
- a charging circuit arranged to supply charging current to the capacitor without the charging current being passed through the resistor, wherein
- the charging circuit includes a charging comparator arranged to compare the stabilized voltage with the output voltage so as to generate a charging control signal, and a charging switch arranged to turn on and off the charging current in accordance with the charging control signal.
A power supply circuit arranged to generate a stabilized voltage from an input voltage, the power supply circuit comprising:
- an output transistor having a first electrode receiving the input voltage, a second electrode, and a control electrode;
- a first node connected to the second electrode of the output transistor directly or via an inserted resistor;
- a control circuit arranged to supply a control voltage based on a feedback voltage corresponding to a voltage at the first node to the control electrode of the output transistor so as to control a state of the output transistor;
- a filter circuit having a filter resistor and a filter capacitor, arranged to smooth the voltage at the first node so as to generate the stabilized voltage at a second node;
- and
- a charging transistor disposed between the first node and the second node, a state of the charging transistor being controlled on the basis of the control voltage, wherein
- when the charging transistor is in an on state, the filter capacitor is charged through the charging transistor.
A power supply circuit arranged to generate a stabilized voltage from an input voltage, the power supply circuit comprising:
- an output transistor having a first electrode receiving the input voltage, a second electrode, and a control electrode;
- a first node connected to the second electrode of the output transistor via an inserted resistor;
- a control circuit arranged to supply a control voltage based on a feedback voltage corresponding to a voltage at the first node to the control electrode of the output transistor so as to control a state of the output transistor;
- a filter circuit having a filter resistor and a filter capacitor, arranged to smooth the voltage at the first node so as to generate the stabilized voltage at a second node;
- and
- a charging transistor disposed between the first node and the second node, a state of the charging transistor being controlled on the basis of a voltage drop across the inserted resistor, wherein
- when the charging transistor is in an on state, the filter capacitor is charged through the charging transistor.
Dependencies are inferred from the claim text.