초록 ▼

A circuit and method for controlling a switching voltage regulator having (1) a switch including one or more switching transistors and (2) an output adapted to supply current at a regulated voltage to a load including an output capacitor. The circuit and method generates a control signal to turn sai

A circuit and method for controlling a switching voltage regulator having (1) a switch including one or more switching transistors and (2) an output adapted to supply current at a regulated voltage to a load including an output capacitor. The circuit and method generates a control signal to turn said one or more switching transistors OFF under operating conditions when the voltage at the output is capable of being maintained substantially at the regulated voltage by the charge on the output capacitor. Such a circuit and method increases the efficiency of the regulator circuit particularly at low average current levels.

대표청구항 ▼

[ What is claimed is:] [1.] Control circuitry for controlling a switching voltage regulator supplying current at a regulated voltage to a load, said regulator having switching circuitry adapted to receive an input voltage and including a switching transistor, a diode, an inductive element, and outpu

[ What is claimed is:] [1.] Control circuitry for controlling a switching voltage regulator supplying current at a regulated voltage to a load, said regulator having switching circuitry adapted to receive an input voltage and including a switching transistor, a diode, an inductive element, and output circuitry, including an output capacitor, said control circuitry including:an error amplifier having inputs coupled to a reference and to said output circuitry;a current comparator circuit having inputs coupled to an output of said error amplifier and to an inductive element current feedback signal;a bias source coupled to an input of said current comparator circuit, said bias source setting a minimum feedback current threshold for said current comparator circuit, said minimum feedback current threshold determining a minimum current level required in said inductive element during each on cycle of said switching transistor to trip said current comparator;a hysteretic comparator having a first input coupled to a reference, a second input coupled to said output circuitry and an output, said output changing from a first state to a second state when the first and second inputs compare in a predetermined manner; anda logic circuit coupled between said hysteretic comparator and said switching transistor which prevents said switching transistor from turning on when said output of said hysteretic comparator is in said second state.