Abstract: A converter circuit and associated control method are disclosed hereby. The converter circuit has an error amplifier to provide an error signal; a proportional amplifier to provide a gain signal according the error signal and an output voltage of the converter circuit; a first comparator, generating a pulse signal according to the gain signal and a comparison signal; and a timer, generating a timing signal according to the pulse signal to indicate the on time and the off time of the converter circuit; and wherein either the gain signal or the comparison signal comprises a ramp component, and wherein the on time of the converter circuit is constant.

Abstract: A switching mode power supply, having: an input port; an output port; an energy storage component and a pair of power switches coupled between input port and the output port; an error amplifier configured to generate an amplified error signal based on the feedback signal and the reference signal; an error comparator configured to generate a frequency control signal based on the amplified error signal and the first sawtooth signal; a peak current generator configured to generate a peak current signal based on the frequency control signal; a peak current comparator configured to generate a current limit signal based on the peak current signal and the current sense signal; and a logic circuit configured to generate a switching signal to control the power switches based on the frequency control signal and the current limit signal.

Abstract: A controller used in a switching converter. The switching converter includes a switching circuit having at least one switch. The controller comprises an on-time control circuit generating an on-time control signal, a slope compensation circuit generating a slope compensation signal, a comparing circuit, a logic circuit and a load detection circuit. The comparing circuit generates a comparison signal based on the slope compensation signal, a reference signal and the output voltage of the switching circuit. The logic circuit generates a control signal to control the ON and OFF switching of the at least one switch based on the on-time control signal and the comparison signal. The load detection circuit detects the load condition. The slope compensation circuit adjusts the slope compensation signal based on the load condition.

Abstract: A failure detector circuit for detecting status of a protected circuit, the failure detector circuit having an operating cycle, has an enabling signal generator, a comparator circuit, a delay circuit. The enabling signal generator enables the comparator for an enable time in each operating cycle. The comparator circuit compares an output of the protected circuit with a reference signal. The delay circuit receives an output signal of the comparator to decide whether a failure occurred within a give delay time.

Abstract: A switch mode power supply system has a constant on-time signal generator, a logic circuit, a feedback circuit, a first ramp signal generator, a second ramp signal generator, a switch circuit having a power switch, and a comparator. A feedback signal from the feedback circuit is compensated by the first ramp signal generator, and a reference signal is compensated by the second ramp signal generator. The comparator compares the compensated feedback signal with the compensated reference signal to indicate an off time of the power switch while the constant on-time signal generator decides the on-time of the power switch.