Control circuits and methods for regulating output voltages using multiple and/or adjustable reference voltages

The present invention relates to control circuits and methods for regulating output voltages using multiple and/or adjustable reference voltages. Methods of regulating an output voltage of a switchedmode power supply having a variable input voltage and a power switch include adjusting a reference voltage to adjust a duty cycle of a control signal for the power switch. The reference voltage may beadjusted as a function of the duty cycle, in response to the duty cycle of the control signal being outside a defined range and/or in the response to a temperature within the switched mode power supply being above a threshold temperature. Other methods include selecting a reference voltage from a plurality of reference voltages based on a determined input voltage and generating a control signal for the power switch as a function of the selected reference voltage to adjust the duty cycle of the control signal. Switched mode power supplies and control circuits for implementing the methods are also disclosed. 本发明涉及使用多个和/