Voltage regulator
AssigneeSeiko Instruments Inc.
InventorTakashi Imura
Life of this patent
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Abstract
A voltage regulator stably operates even when an operating current of a differential amplifier circuit is increased according to an output current. In the voltage regulator, a current mirror circuit for detecting the output current and increasing the operating current of the differential amplifier circuit is provided with a function of providing a delay according to an operation state of the voltage regulator. A simultaneous action of a main feedback system and a feedback system for the output current is eliminated, whereby an internal operating point can be prevented from fluctuating and therefore stability of the operation is improved.
Claims9
A voltage regulator, comprising:
- a differential amplifier circuit for amplifying a difference between a referred voltage obtained by dividing a voltage output with an output transistor and a reference voltage to be output, and for controlling a gate of the output transistor;
- a current source for supplying an operating current of the differential amplifier circuit;
- an output current detection circuit for outputting a current based on a current flowing into the output transistor;
- and
- a current mirror circuit for changing the operating current of the differential amplifier circuit, based on an output current of the output current detection circuit,
- wherein the current mirror circuit provides a delay to an operation for changing the operating current of the differential amplifier circuit after the output current of the output current detection circuit changes based on an operation state of the voltage regulator.
Dependencies are inferred from the claim text.