Step-up/down switching regulator control circuit and step-up/down switching regulator
AssigneeSeiko Instruments Inc.
InventorAtsushi Sakurai
Life of this patent
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Abstract
To provide a step-up/down switching regulator control circuit and the step-up/down switching regulator which are stable in a wide output voltage range from step-up to step-down. According to the present invention, a plurality of phase compensating circuits, a circuit for detecting an input/output voltage, and a switching circuit are disposed in an error amplifier circuit, and a phase compensating circuit is switched to an optimum phase compensating circuit upon detecting the input/output voltage. In addition, the plurality of phase compensating circuits are structured in the exterior of the step-up/down switching regulator control circuit, and a proper phase compensating constant can be set according to an intended purpose.
Claims7
A step-up/down switching regulator control circuit for controlling a step-up/down switching regulator, which conducts a step-up operation when an input voltage is equal to or lower than a given voltage, and conducts a step-down operation when the input voltage is higher than the given voltage to output an output voltage, comprising:
- an error amplifier circuit that compares at least the output voltage with a reference voltage directly or indirectly to output information for holding the output voltage constant;
- a plurality of phase compensating circuits for keeping an operation of the error amplifier circuit stable;
- and
- a selector circuit that selects one or more of the plurality of phase compensating circuits,
- wherein the selector circuit switches the plurality of phase compensating circuits between a step-up time and a step-down time.
A step-up/down switching regulator control circuit for controlling a step-up/down switching regulator, which conducts a step-up operation when an input voltage is equal to or lower than a given voltage, and conducts a step-down operation when the input voltage is higher than the given voltage to output an output voltage, comprising:
- an error amplifier circuit that compares at least the output voltage with a reference voltage directly or indirectly to output information for holding the output voltage constant;
- a plurality of phase compensating circuits for keeping an operation of the error amplifier circuit stable;
- and
- a selector circuit that selects one or more of the plurality of phase compensating circuits,
- wherein the selector circuit switches the plurality of phase compensating circuits when detecting the input voltage.
Dependencies are inferred from the claim text.