Abstract: A controller for generating jitters in a constant current mode of a power converter includes a current pin, an auxiliary pin, a constant current control unit, and a control signal generation unit. The current pin is used for receiving a primary side voltage determined according to a resistor and a primary side current flowing through the power converter. The auxiliary pin is used for receiving a voltage corresponding to an auxiliary winding of the power converter. The constant current control unit is used for generating an adjustment signal according to the primary side voltage, a discharge time corresponding to the voltage, and a reference voltage. The reference voltage has a predetermined range jitter voltage. The control signal generation unit is used for adjusting a period of a gate control signal according to the adjustment signal.

Abstract: A frequency-jittering apparatuses includes an oscillator and a frequency control circuit. The oscillator generates a signal. When the magnitude of the signal exceeds a magnitude of a reference signal, the oscillator operates substantially in a first state; and when the magnitude of the signal is lower than the magnitude of the reference signal, the oscillator operates substantially in a second state different from the first one. The frequency control circuit varies the reference signal to change the frequency of the signal output from the oscillator.

Abstract: A controller for controlling a power converter to output constant power includes a current sensing module, a voltage generation module, and a voltage regulation module. The current sensing module generates a sensing current according to an output current flowing through a secondary side of the power converter. The voltage generation module generates a set voltage corresponding to a reciprocal of the sensing current according to the sensing current. The voltage regulation module generates a regulation voltage to a feedback circuit of the secondary side of the power converter according to the set voltage and a sensing voltage corresponding to an output voltage of the secondary side of the power converter. The feedback circuit and a primary side of the power converter regulate the output voltage according to the regulation voltage, where a product of the output voltage and the output current is a constant value.

Abstract: Integrated circuits, control methods, and related lighting systems are provided. One integrated circuit controls the currents flowing through light-emitting-diode chains, each having several light emitting diodes forward-connected between a main cathode and a main anode while all the main anodes are connected to a power node. The integrated circuit has a short detection node, a constant current source, a voltage clamping circuit, and a short-circuit comparator. The short detection node detects the highest cathode voltage of the main cathodes. The constant current source provides a constant current to the short detection node. While the light-emitting-diode chains are unlit, the voltage clamping circuit clamps the short detection node at a predetermined voltage. When the voltage of the short detection node exceeds a threshold voltage, the short-circuit comparator asserts a fault signal, indicating a short circuit of a light emitting diode.

Abstract: A sample-and-hold circuit for generating a variable sample delay time of a transformer includes a discharge detection unit, a sample delay time generation unit, and a comparator. The discharge detection unit generates a first voltage according to a first turning-on signal and a first reference current. Length of the first turning-on signal is varied with a discharge time of a present period of the transformer. The sample delay time generation unit generates a second voltage according to the first turning-on signal and a second reference current. The comparator generates a sample signal to a control circuit of the transformer according to a first voltage corresponding to a previous period of the transformer and a second voltage corresponding to the present period of the transformer. The first reference current is K times the second reference current, and 0<K<1.

Abstract: A circuit for controlling a latch mode of a pulse width modulation circuit includes a D flip-flop, a voltage generation unit, a comparator, and a logic unit. The D flip-flop generates a switch control signal according to a latch enable signal. The voltage generation unit generates a discharge current, and a voltage divider resistor group included in the voltage generation unit generates a first voltage when the voltage generation unit is turned on according to the switch control signal. A voltage of a predetermined pin of the pulse width modulation circuit is equal to a predetermined voltage when the discharge current is equal to the charge current. The comparator compares a reference voltage with the first voltage to generate a comparison signal. The logic unit generates a clear signal according to the comparison signal. The D flip-flop clears the switch control signal according to the clear signal.

Abstract: A circuit with adjustable phase delay and a feedback voltage includes a delay setting unit and a phase delay signal generator. The delay setting unit generates a delay time according to an external resistor. The phase delay signal generator includes a plurality of phase delay units. Each phase delay unit includes an edge trigger subunit and a signal generation subunit. The edge trigger subunit receives an input signal, and generates a positive edge trigger signal and a negative edge trigger signal according to a positive edge and a negative edge of the input signal, respectively. The signal generation subunit generates and outputs a phase delay signal according to the positive edge trigger signal, the negative edge trigger signal, and the delay time. The phase delay signal lags the input signal for the delay time.

Abstract: An active feedback control integrated circuit applied to an alternating current/direct current converter includes a feedback pin, an operation unit, a control unit, and a controlled-current generation unit. The feedback pin is used for receiving a feedback current of an output feedback unit of the alternating current/direct current converter. The operation unit is used for generating an operation signal according to the feedback current. The control unit is coupled to the operation unit for generating a current control signal. The controlled-current generation unit is coupled to the control unit for generating a controlled current to the feedback pin according to the current control signal.

Abstract: A calibration method for adjusting an offset voltage of a unit is proposed. The unit, capable of operating in a calibration mode or a normal mode, includes a first input terminal, a second input terminal and an output terminal. The calibration method includes: operating the unit in a calibration mode; providing a programmable voltage to the first input terminal; providing a constant voltage to the second input terminal; adjusting the programmable voltage monotonously when an output status of the output terminal is not changed; latching the programmable voltage when the output status toggles; and operating the unit in a normal mode after the output status toggles.

Abstract: Control methods and controller thereof for a power supply including a power switch and an inductor. The power switch is turned on to increase the inductor current through the inductor, which is sensed to generate a current-sense signal. The current-sense signal is added up with an adjusting signal to generate a summation signal. The power switch is turned off if the summation signal is higher than a peak limit. The turn-on time of the power switch is detected to update the adjusting signal.

Abstract: The power management integrated circuit has a startup circuit, a switch controller and a standby controller. Powered by a power source, the startup circuit provides electric power to an operational power source during a startup period. The switch controller controls a power switch to store or release energy in an energy conversion unit. Powered by the power source, the standby controller receives a standby signal. When the standby signal is asserted, the standby controller disables the startup circuit and the switch controller, thereby startup circuit not providing electric power to the operational power source and the switch controller continuously turning off the power switch.

Abstract: A super high voltage device includes a first gate, a second gate, a drain, a first source, a second source, and a third source. The first gate is used for receiving a first control signal generated from a pulse width modulation controller. The second gate is used for receiving a second control signal generated from the pulse width modulation controller. The drain is used for receiving an input voltage. First current flowing from the drain to the first source varies with the first control signal and the input voltage. The second control signal is used for controlling turning-on and turning-off of second current flowing from the drain to the second source and third current flowing from the drain to the third source. The third source is proportional to the second current.

Abstract: Disclosed include power controllers and related control methods. A disclosed power controller has a pulse generator, a sample/hold device, a comparator, and a switch controller. The pulse generator provides an enable signal, defining an enable time. The comparator has two inputs capable of being coupled to a reference signal and a feedback signal, respectively, and an output coupled to a compensation capacitor. When enabled by the enable signal, the comparator charges/discharges the compensation capacitor. The switch controller controls a power switch according to a compensation voltage of the compensation capacitor. A feedback voltage of the feedback signal is able to correspond to an output voltage of the power supply.

Abstract: Power supplies and power controllers are disclosed. A disclosed power supply has a power controller, a power switch, an auxiliary winding, a first circuit and a second circuit. The power controller is a monolithic integrated circuit with a multi-function pin and a gate pin. A control node of the power switch is coupled to the gate pin. The first circuit is coupled between the multi-function pin and the auxiliary winding and has a diode. The second circuit is coupled between the multi-function pin and a ground line, and has a thermistor.

Abstract: A control circuit controls driving of an LED and a current-controlled device controls current through the LED. The current-controlled device has a control node. The control circuit has a driving circuit and a fault detector. In the driving circuit, a first comparator compares a current-setting signal with a sensing signal to generate a first comparison signal. Based on the first comparison signal, a buffer generates a driving signal to the control node and drives the current-controlled device. Within the fault detector, a second comparator compares the first comparison signal with the driving signal, generating a second comparison signal. A third comparator compares the driving signal with a threshold voltage, generating a third comparison signal. A fourth comparator compares the sensing signal with the current-setting signal, generating a fourth comparison signal. A decision maker enables or disables the driving circuit according to the second, third, and fourth comparison signals.

Abstract: A calibration method for adjusting an offset voltage of a unit is proposed. The unit, capable of operating in a calibration mode or a normal mode, includes a first input terminal, a second input terminal and an output terminal. The calibration method includes: operating the unit in a calibration mode; providing a programmable voltage to the first input terminal; providing a constant voltage to the second input terminal; adjusting the programmable voltage monotonously when an output status of the output terminal is not changed; latching the programmable voltage when the output status toggles; and operating the unit in a normal mode after the output status toggles.

Abstract: A control circuit for reducing touch current of a power converter includes an auxiliary pin, a zero-crossing signal generator, a feedback pin, a frequency limiting signal generator, and a gate signal generator. The auxiliary pin receives a voltage corresponding to an auxiliary winding of the power converter. The zero-crossing signal generator generates a zero-crossing signal according to the voltage and a first reference voltage. The feedback pin receives a feedback voltage corresponding to an output voltage of the power converter. The frequency limiting signal generator generates a frequency limiting signal according to the feedback voltage and a second reference voltage. The frequency limiting signal limits the gate control signal to a predetermined frequency. The gate signal generator generates a gate control signal to a power switch of the power converter according to the frequency limiting signal and the zero-crossing signal.

Abstract: A switching power supply includes a power switch, an adjusting circuit and a limit signal generator. The power switch operates according to a switch control signal. The adjusting circuit adjusts the turn-on time of the switch control signal according to a limit signal and a detecting signal which corresponds to the current passing the power switch. When the detecting signal exceeds or is equal to the limit signal, the limit signal generator samples a reference signal and updates the limit signal according to the sampled reference signal.

Abstract: Power control circuits and methods are disclosed, suitable for a power supplier. A power control circuit has a clock generator, a phase controller and a power limiter. The clock generator provides a clock signal, substantially determining switching cycles of a power supply. The phase controller outputs a burst signal based on a group reference signal and a burst initiation signal, and makes a burst period corresponding to a burst signal not less than a group reference period corresponding to the group reference signal. The burst signal is capable of switching the power supplier between a switching state and a non-switching state. The power limiter limits the power transferred by the power supply in every switching cycle, during a burst-up duration after the power supply is switched from the non-switching state to the switching state. The burst initiation signal correlates to an output voltage of the power supplier.

Abstract: A compensation circuit has a resistor, a switch and a compensation capacitor. The resistor and the switch are connected in series between a power node and a compensation node. The compensation capacitor is connected to the compensation node, whose voltage is responsive to the output power source. For a predetermined period of time after the voltage falls below a predetermined value, the switch is open and no current flows through the resistor from the power node to the compensation node.