Abstract: A reference compensating circuit used in a COT control circuit. The reference compensating circuit has an error amplifier, a first current sink, a resistor, a second current sink, a current source and a capacitor. The error amplifier amplifies the difference between a reference signal and a feedback signal and generates an error signal. Based on the error signal, the first current sink generates a current flowing out from a node of the reference compensating circuit. The resistor receives the reference signal at one terminal. The other terminal of the resistor is coupled to the node. The second current sink sinks a current from the node intermittently. The current source sources a current into the node. The capacitor is coupled between the node and a ground to provide a calibrated compensation reference signal to the COT control circuit.

Abstract: A reference signal generator used with a switching mode power supply which converts an input voltage to an output voltage. The reference signal generator provides a reference signal consisting of a constant voltage signal and a variable voltage signal which is varying according to a duty cycle of the switching mode power supply during a startup period of the switching mode power supply and is varying according to a ratio of the input voltage at an end of the startup period to the input voltage of real time after the startup period.

Abstract: A multi-mode power converter and associated method for configuring and controlling a multi-mode power converter. The multi-mode power converter may have a boost operation mode and a buck operation mode. A first transistor is coupled between a switching terminal and a ground, and a second transistor and a third transistor are coupled in series between the switching terminal and an output port of the multi-mode power converter. In the buck mode, an on-resistance of the second transistor is regulated to ensure the multi-mode power converter to operate normally in the buck operation mode.

Abstract: A control circuit for switching converter has an ON signal generating circuit, an OFF signal generating circuit, a first comparator, a second comparator and a logic circuit. The switching converter has a high switch and a low side switch connected in series. The ON signal generating circuit provides an ON signal based on a reference signal and a feedback signal. The OFF signal generating circuit provides an OFF signal. The first comparator provides a first comparing signal based on a comparing result between a first threshold and a current through the high side switch. The second comparator provides a second comparing signal based on a comparing result between a second threshold and a current through the low side switch. The logic circuit provides a first switching signal to control the high side switch ON and OFF and a second switching signal to control the low side switch ON and OFF.

Abstract: A power converter having a bootstrap refresh control circuit and a method for controlling the power converter. The bootstrap refresh control circuit is configured to monitor a bootstrap voltage across a bootstrap capacitor and to provide an enhanced high side driving signal to a high side switch of the power converter. The bootstrap refresh control circuit is further configured to controlling the charging of the bootstrap capacitor through regulating the on and off switching of the high side switch and a low side switch based on the bootstrap voltage. The bootstrap refresh control circuit can refresh the bootstrap voltage in time to support driving the high side switch normally, without causing large spikes in an output voltage of the power converter and without influencing the power conversion efficiency of the power converter.

Abstract: A power converter with bootstrap circuit, the power converter has a high side switch, a low side switch, a bootstrap circuit and a bootstrap capacitor for providing a bootstrap voltage to supply a high side driver of the high side switch. The power converter receives an input voltage and provides an output voltage based on driving the high side switch and the low side switch to switch on and off. The bootstrap circuit has a first comparing circuit, a first comparing circuit, a boost circuit and a second charging circuit. The second charging circuit charges the bootstrap capacitor when a voltage difference between the input voltage and the output voltage is smaller than a voltage threshold.

Abstract: A no-load detecting circuit and the method thereof are disclosed. The no-load detecting circuit may be applied in switching mode power supplies or other circuits. The no-load detecting circuit comprises: a variable resistance circuit coupled in series to a load of the switching mode power supply; and a first comparison circuit coupled to the variable resistance circuit to receive the voltage across the variable resistance circuit, wherein based on the comparison of the voltage across the variable resistance circuit and a first threshold, the first comparison circuit generates a no-load detecting signal indicative of the load status; wherein the equivalent resistance of the variable resistance circuit varies based on the varying of the load of the switching mode power supply.

Abstract: A power converter and a clock module employed for providing a clock signal to the power converter. The power converter converts an input voltage to an output voltage based on at least the switching on and off of a main switch. The clock module monitors a deviation of the output voltage from its desired value and compares the deviation with a predetermined threshold window to provide a clock control signal. The clock module further regulates the clock signal in response to the clock control signal.

Abstract: A power converter with average current detection and the corresponding detecting method and detecting circuit are disclosed. The average current detecting circuit has an average voltage detecting circuit and a voltage-current converting circuit. The average voltage detecting circuit generates a voltage across a detecting resistor by letting an inductor current flowing through an output inductor of the power converter flowing through the detecting resistor. Further, the average voltage detecting circuit samples the voltage across the detecting resistor when a switch of the power converter transits from an on state into an off state and the opposite and then calculates the average value of the two sampled voltages. The voltage-current converting circuit converts the average value into an average current by multiplying the average value by a scaling factor.

Abstract: A power converter having a soft-off control circuit and a variable reference signal generation module and associated method for controlling the power converter. The variable reference signal generation module is configured to provide a variable reference signal to the power converter. The soft-off control circuit is configured to determine whether an input voltage of the power converter exceeds an over-voltage threshold, and to control the variable reference signal to increase once the input voltage reaches the over-voltage threshold and to decrease when the input voltage is lower than the over-voltage threshold. The power converter can regulate an output voltage to increase with the increase of the variable reference signal and to decrease with the decrease of the variable reference signal so that during a soft-off procedure the input voltage may not exceed the over-voltage threshold, enabling the power converter to be safely shut off.

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: An AC signal detector having: a rectify circuit having a first input terminal and a second input terminal configured to receive an AC signal, and an output terminal configured to provide a rectified signal based on the AC signal; a detecting circuit having an input terminal coupled to the output terminal of the rectify circuit to receive the rectified signal, and an output terminal configured to provide a square signal based on the rectified signal; and an unplug indicate circuit having an input terminal coupled to the detecting circuit to receive the square signal, and an output terminal configured to provide an unplug indicate signal based on the square signal.

Abstract: The embodiments of the present invention disclose a charge-pump voltage divider and associated start-up method. The charge-pump voltage divider comprises a start-up circuit that can regulate an inrush current during start up. The start-up circuit comprises a switch, which operates in linear region state during start-up, and operates in switching state after the start-up completes. The charge-pump voltage divider may further comprise a load control switch configured to ensure the start-up is independent of a load current.

Abstract: A power converter having a clock module and a method for controlling a clock signal of the power converter. The clock module is configured to provide the clock signal and to set a clock frequency of the clock signal to a first predetermined frequency at the moment when the power converter is powered on. The clock module is further configured to regulate the clock frequency to increase from the first predetermined frequency to a second predetermined frequency through a predetermined times of step type frequency increase during a startup procedure of the power converter.

Abstract: A switching power converter with an input terminal configured to receive a first input voltage; an output terminal configured to provide an output current to a load, wherein the output current has a peak value and an average value; a power switch; a first loop coupled to the input terminal, wherein the first loop configured to generate a first output signal based on the first input voltage; a second loop configured to generate a second output signal based on the output current; a multiplier configured to generate a multiplying signal based on multiplying the first output signal with the second output signal; and a driving circuit configured to generate a driving signal based on the multiplying signal to control the power switch, so as to reduce the ratio between the peak value and the average value of the output current.

Abstract: A high side buck converter includes a high side transistor, a low side transistor, a sensor, a sensing window generator, an error amplifier, a first comparator and an on-time signal generator. The high side and low side transistors are coupled together to form a switch node which is used as the reference ground of the controller. The sensor senses the output voltage and generates a sensing signal. The sensing window generator generates a sensing window signal. The error amplifier amplifies the error between a feedback signal of the sensing signal and a reference signal during the sensing window, and generates an error signal. The first comparator compares the feedback signal with the error signal and generates a first comparison signal. The on-time signal generator generates an on-time signal based on the first comparison signal, so as to control the high side and low side transistors.

Abstract: A short-circuit protection method for a boost converter is disclosed. In this method, a switch of a switching circuit of the boost converter is turned on and a control voltage with a gradually increasing magnitude is supplied to control a short-circuit protection switch coupled between an input voltage and the switching circuit when the boost converter starts up. Then, a current flowing through the switch is detected and compared with a predetermined value. The switch is turned off and a preset time period is initiated if the current is higher than the predetermined value. It is detected whether a short-circuit event occurs at an output terminal of the boost converter at the end of the preset time period. If the short-circuit event occurs, the short-circuit protection switch is then turned off.

Abstract: A power converter having a bootstrap refresh control circuit and a method for controlling the power converter. The bootstrap refresh control circuit is configured to monitor a bootstrap voltage across a bootstrap capacitor and to provide an enhanced high side driving signal to a high side switch of the power converter. The bootstrap refresh control circuit is further configured to controlling the charging of the bootstrap capacitor through regulating the on and off switching of the high side switch and a low side switch based on the bootstrap voltage. The bootstrap refresh control circuit can refresh the bootstrap voltage in time to support driving the high side switch normally, without causing large spikes in an output voltage of the power converter and without influencing the power conversion efficiency of the power converter.

Abstract: A switching converter providing an output voltage has a first switch and a control circuit. The control circuit provides an auxiliary power supply voltage, and a switching control signal to control the first switch based on the output voltage and a reference signal. The switching converter is shut down by the control circuit when a fault happens, and the switching converter restarts when the auxiliary power supply voltage decreases to a first threshold.

Abstract: A power converter and a clock module employed for providing a clock signal to the power converter. The power converter converts an input voltage to an output voltage based on at least the switching on and off of a main switch. The clock module monitors a deviation of the output voltage from its desired value and compares the deviation with a predetermined threshold window to provide a clock control signal. The clock module further regulates the clock signal in response to the clock control signal.