Abstract: The present invention provides a high-side signal sensing circuit. The high-side signal sensing circuit comprises a signal-to-current converter, a second transistor and a resistor. The signal-to-current converter has a first transistor generating a mirror current in response to an input signal. The second transistor cascaded with the first transistor is coupled to receive the mirror current. The resistor generates an output signal in response to the mirror current. Wherein, the level of the output signal is corrected to the level of the input signal.

Abstract: The present invention provides a control circuit for dimming LED lighting. The control circuit comprises a voltage divider, a controller and an adaptive bleeder. The voltage divider receives an input voltage from an input terminal to generate a dimming signal. The controller generates a switching signal in response to the dimming signal. The controller further generates a control signal in response to the input voltage. The adaptive bleeder receives the control signal and draws a bleeder current from the input terminal in response to the control signal.

Abstract: An offline LED lighting circuit comprises a controller and a dimming circuit. The controller generates a switching signal to switch a transformer for generating an output voltage and an output current at an output terminal of the offline LED lighting circuit to drive LEDs. The dimming circuit is coupled to the controller to modulate the switching signal in response to a dimming signal. A first reference voltage and a second reference voltage of the controller are generated in response to the dimming signal. The switching signal is modulated by the first reference voltage and the second reference voltage. The controller regulates the output voltage at a first output level and a second output level in response to both the first reference voltage and the second reference voltage. The second output level is lower than the first output level.

Abstract: The present invention provides a controller for a power converter. The controller comprises a PWM circuit, a detection circuit, a signal generator, an oscillation circuit, a valley-lock circuit, a timing circuit and a burst circuit. The PWM circuit generates a switching signal coupled to switch a transformer of the power converter. A feedback signal is coupled to control and disable the switching signal. The detection circuit is coupled to the transformer via a resistor for generating a valley signal in response to a waveform obtained from the transformer. The signal generator is coupled to receive the feedback signal and the valley signal for generating an enabling signal. The oscillation circuit generates a maximum frequency signal. The maximum frequency signal associates with the enabling signal to generate a turning-on signal. The turning-on signal is coupled to enable the switching signal. A maximum frequency of the turning-on signal is limited.

Abstract: An adaptive filter circuit for sampling a reflected voltage of a transformer of a power converter includes a first switch for receiving the reflected voltage, a resistor having a first terminal and a second terminal, the first terminal of the resistor being coupled to the first switch, a capacitor coupled to the second terminal of the resistor for holding the reflected voltage, and a second switch coupled to the resistor in parallel, wherein the resistor and the capacitor develop a filter for sampling the reflected voltage which is sampled without filtering by the filter in a first period during a disable period of a switching signal and also sampled with filtering by the filter in a second period during the disable period of the switching signal.

Abstract: This invention provides a control circuit for burst switching of a power converter comprising: an adaptive circuit generating an adaptive threshold in response to a feedback signal correlated to an output load of the power converter; and a switching circuit generating a switching signal to switch a transformer of the power converter in accordance with the adaptive threshold and the feedback signal for regulating an output of the power converter.

Abstract: The present invention provides a control circuit having a multi-function terminal. The control circuit comprises a switching circuit, a sample-and-hold circuit, a detection circuit, and a comparator. The sample-and-hold circuit is coupled to the multi-function terminal for generating a sample voltage by sampling the feedback signal during a first period. The detection circuit is coupled to the multi-function terminal during a second period for generating a detection voltage. The comparator compares the detection voltage and the sample voltage for generating an over-temperature signal, wherein the over-temperature signal is couple to disable the switching signal.

Abstract: An exemplary embodiment of a power converter is provided. The power converter includes a transformer, a power device, a switching controller, and a capacitor. The power device is coupled to the transformer for switching the transformer to product output of the power converter. The switching controller receives a feedback signal for generating a switching signal coupled to drive the power device. An input circuit of the switching controller is coupled to the transformer to sample an input signal for generating the feedback signal, and the input signal is correlated to the output of the power converter. The capacitor is coupled to the switching controller to provide frequency compensation for a feedback loop of the power converter. Input of the power converter is without an electrolytic capacitor, and a maximum output current of the power converter is a constant current.

Abstract: This invention provides a primary-side controlled power converter comprising: an RC network coupled to an auxiliary winding of a transformer of the primary-side controlled power converter to detect a reflected voltage of the transformer for generating a reflected signal, and a controller coupled to the RC network to receive the reflected signal for generating a switching signal; wherein the RC network develops a zero to provide a high-frequency path for shortening a rising time and a settling time of the reflected signal.

Abstract: A power management interface is provided and includes a switch, a transmitting circuit, and a receiving circuit. The switch is coupled to an AC power line for controlling a power line signal to a load. The transmitting circuit generates a switching signal to control the switch and achieve a phase modulation to the power line signal in response to a transmitting-data. The receiving circuit is coupled to receive the power line signal for detecting a phase of the power line signal and generating a receiving-data to control power of the load. The receiving-data is generated in accordance with the phase detection of the power line signal and correlated to the transmitting-data.

Abstract: The present invention provides a power converter. The power converter includes a transformer, a power switch and a controller. The transformer has a primary winding, a secondary winding and an auxiliary winding. The power switch is coupled to the primary winding of the transformer to regulate the power converter. The controller has an output terminal for generating a driving signal to switch the power switch in response to a switching signal. A thermal resistor is coupled to the output terminal of the controller. The driving signal is adjusted across the thermal resistor during an off-period of the switching signal.

Abstract: A method and an apparatus of operating a primary-side-regulation power converter at both continuous current mode and discontinuous current mode are provided. The apparatus includes a switching circuit, a signal generator, a correlation circuit, and a feedback modulator. The signal generator generates a half signal and a second sampling pulse in response to a switching signal. The correlation circuit receives the half signal, the second sampling pulse and a switching-current signal for generating a modulating current. The feedback modulator modulates a feedback signal in response to the modulating current, a detection signal and the switching signal. The detection signal obtained from a transformer is correlated to an output voltage of the primary-side-regulation power converter. An on-period of the half signal is half of an on-period of the switching signal. The switching-current signal is sampled at a falling-edge of the half signal.

Abstract: A synchronous rectifier circuit of a switching power converter is provided and includes first and second power transistors and first and second diodes connected to a transformer and an output of the power converter for rectifying. An arbiter circuit generates a lock signal to prevent the second power transistor from being turned on when the first power transistor is turned on. A controller generates a drive signal to control the first power transistor according to an on signal and an off signal. A phase-lock circuit generates the off signal according to the on signal. The on signal is enabled once the first diode is forward biased. The one signal enables the drive signal for turning on the first power transistor. The off signal disables the drive signal for turning off the first power transistor. The off signal is enabled before the disabling of the on signal.

Abstract: A controller for a power converter is provided. The controller includes a PWM circuit, a detection circuit, a signal generation circuit and an oscillation circuit. The PWM circuit generates a switching signal coupled to switch a transformer of the power converter. A feedback signal is coupled to the PWM circuit to disable the switching signal. The detection circuit is coupled to the transformer via a resistor for generating a valley signal in response to a signal waveform of the transformer. The signal generation circuit is coupled to receive the feedback signal and the valley signal for generating an enabling signal. The oscillation circuit generates a maximum frequency signal. The maximum frequency signal associates with the enabling signal to generate a pulse signal. The feedback signal is correlated to an output load of the power converter. The maximum frequency of the pulse signal is limited.

Abstract: The present invention provides a correction circuit for a power converter. The correction circuit includes a sampling circuit, a demagnetizing-time circuit, a duty circuit, and a compensation circuit. The sampling circuit generates an average-current signal in response to a switching current of the power converter. The demagnetizing-time circuit generates a discharging-time signal in response to a switching signal and an input-voltage signal. The duty circuit generates a duty signal in response to the discharging-time signal, an on-time of the switching signal, and a switching period of the switching signal. The compensation circuit is coupled to receive the average-current signal and the duty signal for generating a corrected signal. The switching signal is utilized to switch a magnetic device for regulating an output voltage of the power converter. The corrected signal is coupled to generate the switching signal.

Abstract: An offline LED driving circuit includes a controller, a shunt regulator, an opto-coupler, and a dimming circuit. The controller generates a switching signal to switch a transformer for providing an output voltage and an output current. The shunt regulator is coupled to an output terminal of the LED driving circuit for providing a feedback signal to the controller via the opto-coupler. The dimming circuit coupled to the shunt regulator modulates the feedback signal at a first feedback level and a second feedback level in response to a dimming signal. The output voltage is respectively regulated at a first output level and a second output level in response to the first feedback level and the second feedback level of the feedback signal. The duty cycle of the switching signal will be varied in a soft-start manner when the feedback signal changes from the second feedback level to the first feedback level.

Abstract: A Schottky device and a semiconductor process of making the same are provided. The Schottky device comprises a substrate, a deep well, a Schottky contact, and an Ohmic contact. The substrate is doped with a first type of ions. The deep well is doped with a second type of ions, and formed in the substrate. The Schottky contact contacts a first electrode with the deep well. The Ohmic contact contacts a second electrode with a heavily doped region with the second type of ions in the deep well. Wherein the deep well has a geometry gap with a width formed under the Schottky contact, the first type of ions and the second type of ions are complementary, and the width of the gap adjusts the breakdown voltage.

Abstract: A motor rotor includes an annular body and a positioning protrusion installed on an inner lateral surface of the annular body. A magnetic body may be positioned by propping its lateral surface against the positioning protrusion, without the use of additional jigs. Therefore, the time needed to assemble the magnetic body to the annular body is saved, and the manufacturing cost of the whole motor is reduced.

Abstract: A control circuit for a switching power converter is provided. The control circuit is installed between a secondary side and an output of the power converter and coupled to control a switching device. The control circuit includes a linear predict circuit, a reset circuit, a charge/discharge circuit, and a PWM circuit. The linear predict circuit is coupled to receive a linear predict signal from the secondary side for generating a charging signal. The reset circuit is couple to receive a resetting signal for generating a discharging signal. The charge/discharge circuit is coupled to receive the charging signal and the discharging signal for generating a ramp signal. The PWM circuit is coupled to receive the linear predict signal for enabling a switching signal and receive the ramp signal for resetting the switching signal.

Abstract: A motor rotor includes an annular body and a magnetic body installed on an inner lateral surface of the annular body. The magnetic body has a first curved surface and a second curved surface opposing the first curved surface. The magnetic body props against the inner lateral surface of the annular body via the first curved surface. The first curved surface has a first curvature less than a second curvature of the second curved surface. Because the magnetic body of the motor rotor has an uneven thickness, and an air gap interval formed between the motor rotor and the stator also has an uneven width, forces applied to a region where the magnetic forces change directions are smooth. Therefore, the vibration of the whole motor is reduced, and the noises are suppressed effectively.