Abstract: An AC-to-DC power supply converts an input power source into an output power source, capable of having a single stage to achieve PFC and output regulation at the same time. The AC-to-DC power supply has an inductive device, a main switch, a backup circuit providing a backup power, and a power controller. The power controller controls the main switch and the backup circuit to generate a power transfer cycle with an input slot, an internal-burst slot, and a demagnetization time. During the input slot, the power controller turns ON the main switch, so the input power source supplies power to increase electromagnetic energy of the inductive device. During the internal-burst slot, the backup power supplies power to the inductive device. During the demagnetization time, the electromagnetic energy releases to supply power to the output power source or the backup power.

Abstract: A rectifier circuit has a cathode node, an anode node, a rectifier switch, an auxiliary switch, an operating power capacitor and a rectifier controller supplied with power by the operating power capacitor. The rectifier switch is electrically connected to the auxiliary switch. When the rectifier controller turns OFF both the rectifier and auxiliary switches, the rectifier circuit supports a first loop, directing a first current to flow into the rectifier circuit from the anode node, through the operating power capacitor, and away the rectifier circuit from the cathode, so the operating power capacitor is charged. When the rectifier controller turns ON both the rectifier and auxiliary switches, the rectifier circuit supports a second loop directing a second current to flow into the rectifier circuit from the anode node, through the rectifier switch, and away the rectifier circuit from the cathode, without charging the operating power capacitor.

Abstract: An isolated power supplies converts an input power source in a primary side into an output power source in a secondary side, capable of transmitting a signal from the secondary side to the primary side via a transformer. The transformer has a primary winding connected with a main switch, and a secondary winding connected with a secondary-side switch. A primary-side controller controls the main switch. A secondary-side controller controls the secondary-side switch and detects a demagnetization time of the transformer. Before the end of the demagnetization time, the secondary-side controller turns OFF the secondary-side switch to signal, via the transformer, the primary-side controller, which in response turns ON the main switch to operate the isolated power supply in a continuous-conduction mode or in a boundary mode.

Abstract: A rectifier circuit has a cathode node, an anode node, a rectifier switch, an auxiliary switch, an operating power capacitor and a rectifier controller supplied with power by the operating power capacitor. The rectifier switch is electrically connected to the auxiliary switch. When the rectifier controller turns OFF both the rectifier and auxiliary switches, the rectifier circuit supports a first loop, directing a first current to flow into the rectifier circuit from the anode node, through the operating power capacitor, and away the rectifier circuit from the cathode, so the operating power capacitor is charged. When the rectifier controller turns ON both the rectifier and auxiliary switches, the rectifier circuit supports a second loop directing a second current to flow into the rectifier circuit from the anode node, through the rectifier switch, and away the rectifier circuit from the cathode, without charging the operating power capacitor.

Abstract: A timing controller provides adaptive timings to control a synchronous rectifier with a body diode. The timing controller has a ramp generator providing a ramp signal at a first capacitor. The ramp signal corresponds to a discharge time when the body diode is forward biased. A second capacitor records an estimated duration signal. An update circuit is connected between the first and second capacitors, for shorting the first and second capacitor to update the estimated duration signal by charge sharing. A comparator with two inputs coupled to the ramp signal and the estimated duration signal respectively compares the ramp signal and the estimated duration signal to control the synchronous rectifier.

Abstract: Disclosed include switching-mode power supplies and control methods thereof. A disclosed switching-mode power supply is coupled to an input power node and a ground node, comprising a controller, a first inductor, and a bootstrap circuit. The controller is for controlling a power switch coupled to the input power node and a connection node. The controller is powered by the connection node and an operation power node. The first inductor is coupled between the connection node and a discharge node. The bootstrap circuit is coupled between the discharge node, the operation power node and the connection node, to make an operation voltage at the operation power node substantially not less than a discharge voltage at the discharge node. The discharge node is coupled to power an output load.

Abstract: In a switching mode power supply, a power controlling circuit includes a phase generator and a phase controller. The phase generator provides a clock signal. The phase controller detects phases of a phase reference signal and a burst initialization signal so as to generate a burst signal, and causes a phase of the burst signal to not be earlier than the phase of the group reference signal. The burst signal is utilized for switching the power supply between a non-switching state and a switching state. The group reference signal is generated according to the clock signal and has a lower frequency than the clock signal. The burst initialization signal is controlled by an output voltage source of the power supply.

Abstract: A timing controller provides adaptive timings to control a synchronous rectifier with a body diode. The timing controller has a ramp generator providing a ramp signal at a first capacitor. The ramp signal corresponds to a discharge time when the body diode is forward biased. A second capacitor records an estimated duration signal. An update circuit is connected between the first and second capacitors, for shorting the first and second capacitor to update the estimated duration signal by charge sharing. A comparator with two inputs coupled to the ramp signal and the estimated duration signal respectively compares the ramp signal and the estimated duration signal to control the synchronous rectifier.

Abstract: An embodiment provides a control method capable of controlling a switching-mode power supply to provide an output power source. The switching-mode power supply has a winding coupled to an input power source and controlled by a switch to be energized or de-energized. The maximum current peak through the winding is set to be a predetermined value. A discharge time of the winding in a switching cycle period is detected. The switching cycle period of the switch is controlled to keep the ratio of the discharge time to the switching cycle period as a constant.

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: 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: 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.

Abstract: A switch controller for switching power supply is coupled to an auxiliary winding of the switching power supply through a detecting resistor. The switch controller provides a detecting current passing through the detecting resistor for keeping the voltage level of a detecting signal transmitted by the detecting resistor higher than a predetermined voltage. In this way, the switch controller can avoid the latch-up phenomenon caused by receiving the detecting signal of the negative voltage level. In addition, the switch controller can detect the magnitude of an input voltage of the switching power supply by means of the detecting current, and accordingly control the operation of the switching power supply.

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: An embodiment provides a control method capable of controlling a switching-mode power supply to provide an output power source. The switching-mode power supply has a winding coupled to an input power source and controlled by a switch to be energized or de-energized. The maximum current peak through the winding is set to be a predetermined value. A discharge time of the winding in a switching cycle period is detected. The switching cycle period of the switch is controlled to keep the ratio of the discharge time to the switching cycle period as a constant.

Abstract: Disclosed include switching-mode power supplies and control methods thereof. A disclosed switching-mode power supply is coupled to an input power node and a ground node, comprising a controller, a first inductor, and a bootstrap circuit. The controller is for controlling a power switch coupled to the input power node and a connection node. The controller is powered by the connection node and an operation power node. The first inductor is coupled between the connection node and a discharge node. The bootstrap circuit is coupled between the discharge node, the operation power node and the connection node, to make an operation voltage at the operation power node substantially not less than a discharge voltage at the discharge node. The discharge node is coupled to power an output load.

Abstract: Current control method and apparatus are disclosed. A current limiter is coupled to a switch connected in series with an energy transfer element of a power supply. The current limiter detects a current flowing through the switch and, when the current exceeds a current limit signal, turns off the switch. A limit signal generator provides the current limit signal, detects the maximum current value of the current, and updates the current limit signal according to the maximum current value and an ideal current limit value.

Abstract: In a switching mode power supply, a power controlling circuit includes a phase generator and a phase controller. The phase generator provides a clock signal. The phase controller detects phases of a phase reference signal and a burst initialization signal so as to generate a burst signal, and causes a phase of the burst signal to not be earlier than the phase of the group reference signal. The burst signal is utilized for switching the power supply between a non-switching state and a switching state. The group reference signal is generated according to the clock signal and has a lower frequency than the clock signal. The burst initialization signal is controlled by an output voltage source of the power supply.

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 high-voltage device provides a constant current drained from a high voltage source to charge a filter capacitor, where a voltage level of the higher voltage source is higher than 90 volts. When the operation voltage of the filter capacitor exceeds a first predetermined value, the charging of the filter capacitor by the constant current is stopped. A feedback loop is then used to maintain the operating voltage at substantially a second predetermined value lower than the first one.