Step-up/down switching regulator control circuit and step-up/down switching regulator
View Patent ↗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.
1. 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.
2. 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.
3. A step-up/down switching regulator control circuit according to claim 2 , wherein one or more of the plurality of phase compensating circuits are disposed in the exterior of the step-up/down switching regulator control circuit.
4. 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:
a step-up/down switching regulator control circuit according to claim 3 for controlling the output voltage.
5. 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:
a step-up/down switching regulator control circuit according to claim 2 for controlling the output voltage.
6. 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:
a step-up/down switching regulator control circuit according to claim 1 for controlling the output voltage.
7. A step-up/down switching regulator control circuit according to claim 1 , wherein one or more of the plurality of phase compensating circuits are disposed in the exterior of the step-up/down switching regulator control circuit.