Low drop-out switching regulator architecture
First Claim
Patent Images
1. A switching voltage regulator circuit comprising:
- a switch circuit coupled to a source of input voltage, said switch circuit comprising a first switching element coupled to a switch node;
a driver circuit comprising a first driver coupled to said first switching element;
an output circuit coupled to said switch circuit, said output circuit comprising an inductive storage element and a capacitive storage element coupled between an output terminal and ground;
a control circuit that generates a control signal based at least in part on an oscillator signal from an oscillator circuit, said control circuit being coupled to said driver circuit to provide said control signal to said driver circuit; and
a limiting circuit coupled to said control circuit to change the state of said control signal when said first switching element has been in a continuous conductive state for a predetermined number of oscillator cycles.
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Abstract
Circuits and methods are provided for low drop-out operation of switching regulator circuits that include a switching transistor and an output circuit adapted to supply current at a regulated voltage to a load. The circuits and methods generate a limiting signal that allows the switching transistor to remain in a continuous conductive state for a predetermined number of oscillator cycles. The predetermined number of oscillator cycles is preferably set by a counter that initiates a signal that turns the switching transistor OFF.
107 Citations
28 Claims
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1. A switching voltage regulator circuit comprising:
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a switch circuit coupled to a source of input voltage, said switch circuit comprising a first switching element coupled to a switch node; a driver circuit comprising a first driver coupled to said first switching element; an output circuit coupled to said switch circuit, said output circuit comprising an inductive storage element and a capacitive storage element coupled between an output terminal and ground; a control circuit that generates a control signal based at least in part on an oscillator signal from an oscillator circuit, said control circuit being coupled to said driver circuit to provide said control signal to said driver circuit; and a limiting circuit coupled to said control circuit to change the state of said control signal when said first switching element has been in a continuous conductive state for a predetermined number of oscillator cycles. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
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25. A method for controlling a switching voltage regulator comprising the steps of:
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producing a first control signal based at least in part on an oscillator signal; applying said first control signal to a driver circuit, said driver circuit comprising a first driver that produces a first driver signal; driving with said first driver signal a switch circuit coupled to a source of input voltage, said switch circuit comprising a first switching element coupled to a switch node; providing a switch signal from said switch circuit to an output circuit that produces a regulated output signal; monitoring said regulated output signal; modifying said first control signal based at least in part on said regulated output signal; and combining said control signal with a limiting signal that allows said first switching element to be in a continuous conductive state for a predetermined number of oscillator cycles. - View Dependent Claims (26, 27, 28)
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Specification