Soft start circuit, power supply unit and electric equipment
AssigneeRohm Co., Ltd.
InventorAtsushi Kitagawa
Life of this patent
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Abstract
A soft start circuit includes a constant current source for generating a constant current, a first current mirror circuit for generating from the constant current a first mirror current, a second current mirror circuit for generating from the constant current a second mirror current smaller than the first mirror current, and a capacitor into which a difference between the first mirror current and the second mirror current is introduced, wherein a divided voltage of a charging voltage thereof is output as a soft start voltage. The soft start circuit provides a gradual soft start voltage.
Claims14
A soft start circuit comprising:
- a first constant current source arranged to generate a first constant current;
- a second constant current source arranged to generate a second constant current smaller than the first constant current;
- and
- a capacitor into which an electric current that is a difference between the second constant current and the first constant current is introduced;
- wherein
- a charging voltage at one end of the capacitor is output as a comparison voltage for a soft start.
A soft start circuit comprising:
- a constant current source arranged to generate a constant current;
- a first mirror current circuit arranged to generate from the constant current a first mirror current;
- a second mirror current circuit arranged to generate from the constant current a second mirror current smaller than the first mirror current;
- and
- a capacitor into which an electric current that is a difference between the second mirror current and the first mirror current is introduced;
- wherein
- a charging voltage at one end of the capacitor is output as a comparison voltage for a soft start.
Dependencies are inferred from the claim text.