Abstract: A flyback power converter circuit includes: a transformer; a primary side switch, for controlling a primary winding to convert an input voltage to an output voltage and an internal voltage; a primary side control circuit, which is powered by the internal voltage; the primary side control circuit generates a switching signal according to a feedback signal, to operate the primary side switch; a secondary side control circuit, which generates the feedback signal according the output voltage; and a dummy load circuit, which is coupled to the output voltage, wherein when the output voltage drops to or is lower than a predetermined threshold, the dummy load circuit generates a dummy load current, to determine the feedback signal, so that the internal voltage is not undesirably low. When the output voltage exceeds the predetermined threshold, the dummy load circuit adjusts the dummy load current to zero current.

Abstract: A flyback power converter includes: a transformer, a primary side switch, a snubber capacitor and an active clamp snubber. The snubber capacitor is charged by a leakage inductance current of a primary winding fora snubber period following after a time point when the primary side switch is turned OFF. The active clamp snubber includes a snubber control switch which is connected in series to the snubber capacitor. The series circuit of the snubber control switch and the snubber capacitor is connected in parallel to the primary winding. The leakage inductance current charges the snubber capacitor through the snubber control switch during the snubber period. The snubber capacitor provides a capacitor voltage as electrical power of the active clamp snubber. A voltage level of a reference node between the snubber control switch and the snubber capacitor serves as a snubber ground level of the active clamp snubber.

Abstract: A switching controller circuit for controlling a flyback power converter includes: a power transformer, a primary side controller circuit and a secondary side controller circuit. The power transformer is coupled between the input voltage and the output voltage in an isolated manner. The primary side controller circuit controls a primary side switch of the flyback power converter. The secondary side controller circuit generates a synchronous rectification (SR) signal, to control an SR switch of the flyback power converter. The SR signal includes an SR pulse and a soft switching (SS) pulse. The SR pulse controls the SR switch to be ON for an SR period, to achieve synchronous rectification at the secondary side. The SS pulse controls the SR switch to be ON for an SS period, to achieve soft switching of the primary side switch.

Abstract: A flyback power converter includes a primary side controller circuit for controlling a primary side switch; and a secondary side controller circuit for generating an SR (Synchronous Rectification) signal to control an SR switch. The SR signal includes an SR pulse and a ZVS (Zero Voltage Switching) pulse. The SR pulse controls the SR switch for synchronous rectification at the secondary side. The secondary side controller circuit samples and holds a voltage at a first end of the SR switch as a first voltage at a timing between the end of the ZVS pulse and the beginning of the SR pulse, and determines a length of the ZVS pulse so as to control the SR switch to be conductive for a ZVS time period, whereby the primary side switch achieves ZVS. The first voltage is proportional to an input voltage.

Abstract: A control circuit for a programmable power supply is provided. It comprises a reference generation circuit generating a voltage-reference signal and a current-reference signal for regulating an output voltage and an output current of the power supply. A feedback circuit detects the output voltage and the output current for generating a feedback signal in accordance with the voltage-reference signal and the current-reference signal. A switching controller generates a switching signal coupled to switch a transformer for generating the output voltage and the output current in accordance with the feedback signal. A micro-controller controls the reference generation circuit. The micro-controller, the reference generation circuit, and the feedback circuit are equipped in the secondary side of the transformer. The switching controller is equipped in the primary side of the transformer. The control circuit can achieve good performance for the programmable power supply.

Abstract: The present invention provides a high voltage device and a manufacturing method thereof. The high voltage device includes: a semiconductor layer, a drift oxide region, a well, a body region, a gate, at least one sub-gate, a source, and a drain. The drift oxide region is located on a drift region in an operation region. The sub-gate is formed on the drift oxide region right above the drift region. The sub-gate is parallel with the gate. A conductive layer of the gate has a first conductivity type, and a conductive layer of the sub-gate has a second conductivity type or is an intrinsic semiconductor structure.

Abstract: A flyback power converter circuit includes: a transformer; a primary side switch, for controlling a primary winding to convert an input voltage to an output voltage and an internal voltage; a primary side control circuit, which is powered by the internal voltage; the primary side control circuit generates a switching signal according to a feedback signal, to operate the primary side switch; a secondary side control circuit, which generates the feedback signal according the output voltage; and a dummy load circuit, which is coupled to the output voltage, wherein when the output voltage drops to or is lower than a predetermined threshold, the dummy load circuit generates a dummy load current, to determine the feedback signal, so that the internal voltage is not undesirably low. When the output voltage exceeds the predetermined threshold, the dummy load circuit adjusts the dummy load current to zero current.

Abstract: A power transmission apparatus includes a power delivery unit generating a power, a load unit receiving the power, a cable, at least a connector, at least a power switch, and a communication interface. The power delivery unit and the load unit is coupled by the connector and the cable, and the power is delivered through the cable and the connector. A voltage threshold is determined according to a delivery current of the power or a load current of the load unit. When a voltage difference between a delivery voltage of the power and a load voltage of the load unit is larger than the voltage threshold, the power switch is turned OFF, wherein information of one of the delivery voltage, the load voltage, the delivery current, and/or the load current is provided through the communication interface.

Abstract: An LED (Light Emitting Diode) drive circuit includes a magnetic device, a power transistor, a current-sense resistor, and a controller. The magnetic device has a first terminal for receiving an input voltage derived from an input of the LED drive circuit, and a second terminal. The magnetic device generates an output current to drive at least one LED. The power transistor has a drain coupled to the second terminal of the magnetic device, a control terminal, and a source. The current-sense resistor has a first terminal coupled to the source of the power transistor for forming a current input signal, and a second terminal coupled to ground. The controller generates a switching signal coupled to control the power transistor to switch current through the magnetic device based on both a programmable signal derived from the input of the LED drive circuit, and the current input signal.

Abstract: The present invention provides a charging apparatus, a charging control circuit, and a charging control method. The charging apparatus includes a power conversion circuit for generating a DC output voltage and charging a battery by a DC output current, and a charging control circuit for controlling the power conversion circuit. When the DC output voltage or the battery voltage rises to a first reference threshold voltage, the DC output current is adjusted downward by a current down step, and when the DC output voltage or the battery voltage falls to a second reference threshold voltage, the DC output current is adjusted upward by a current up step.

Abstract: A rechargeable battery is coupled to a power delivery unit or an external load unit. In a charging mode, the power delivery unit converts an input power to a converted voltage and/or current. A charging circuit converts the converted voltage and/or current to a charging voltage and/or current for charging the rechargeable battery. Power data is communicated between the power delivery unit and the rechargeable battery by: 1) the power delivery unit adjusting the converted voltage, wherein the power data is expressed by plural voltage levels of the converted voltage; and/or 2) the rechargeable battery adjusting a battery input current, wherein the power data is expressed by plural current levels of the battery input current. At least one of the converted voltage, the converted current, the charging voltage, or the charging current is adjusted according to the power data.

Abstract: A ZVS (zero voltage switching) control circuit for use in a flyback power converter includes a primary side controller circuit, a secondary side controller circuit, and a pulse transformer. In one switching cycle, a synchronous rectifier transistor is turned ON twice to generate a circulation current at the primary side winding, and after the synchronous rectifier transistor is turned OFF, the power transistor is turned ON for zero voltage switching. A synchronous signal coupled between the primary side and the secondary side is employed to synchronize the power transistor and the synchronous transistor. The synchronous signal also triggers an SR-ZVS pulse to turn ON the synchronous rectifier transistor for achieving the zero voltage switching when the power transistor is turned ON.

Abstract: A ZVS (zero voltage switching) control circuit for use in a flyback power converter includes a primary side controller and a secondary side controller. The primary side controller generates a switching signal to control a power transformer through a power transistor to generate an output voltage. The secondary side controller generates an SR (synchronous rectifier) signal to control an SR transistor at a secondary side of the power transformer. The SR signal includes an SR-control pulse and a ZVS pulse. The SR-control pulse controls the SR transistor according to a demagnetizing period of the power transformer. The ZVS pulse determines the starting timing of the switching signal to achieve zero voltage switching for the power transistor. The secondary side controller generates the ZVS pulse after a delay time from when the power transformer is demagnetized. The delay time is determined according to an output load of the output voltage.

Abstract: A ZVS (zero voltage switching) control circuit for use in a flyback power converter includes a primary side controller and a secondary side controller. The primary side controller generates a switching signal to control a power transformer through a power transistor to generate an output voltage. The secondary side controller generates an SR (synchronous rectifier) signal to control an SR transistor at a secondary side of the power transformer. The SR signal includes an SR-control pulse and a ZVS pulse. The SR-control pulse controls the SR transistor according to a demagnetizing period of the power transformer. The ZVS pulse determines the starting timing of the switching signal to achieve zero voltage switching for the power transistor. The secondary side controller generates the ZVS pulse after a delay time from when the power transformer is demagnetized. The delay time is determined according to an output load of the output voltage.

Abstract: An LED drive circuit includes a controller, generating a switching signal to switch a magnetic device that receives an input voltage derived from an input of the LED drive circuit, for generating an output current to drive at least a LED. The controller includes an input circuit receiving a programmable signal correlated to the input of the LED drive circuit to generate a programmable current, the programmable current modulating a current input signal correlated to a switching current of the magnetic device to form a modulated current input signal, and a comparison circuit comparing a signal sourced from an oscillator and a voltage potential generated in response to the modulated current input signal for generating a current control signal. The switching signal is controlled in response to the current control signal for regulating the output current, and a level of the output current is correlated to the current control signal.

Abstract: An interface device includes: at least one configuration channel terminal for communicating configuration information, wherein whether the interface device itself is in connection and whether the interface device itself is at a high voltage side or a low voltage side are determined according to a voltage or current status at the configuration channel terminal; a multi-functional transmission line, which includes a thermistor; and a temperature monitor circuit, coupled to the multi-functional transmission line, for sensing a temperature status to generate a temperature sensing signal. When two interface devices are connected with each other, the thermistor and the temperature monitor circuit can be located together in one of the interface devices or separately located in different interface devices.

Abstract: An LED drive circuit includes a controller, generating a switching signal to switch a magnetic device that receives an input voltage derived from an input of the LED drive circuit, for generating an output current to drive at least a LED. The controller includes an input circuit receiving a programmable signal correlated to the input of the LED drive circuit to generate a programmable current, the programmable current modulating a current input signal correlated to a switching current of the magnetic device to form a modulated current input signal, and a comparison circuit comparing a signal sourced from an oscillator and a voltage potential generated in response to the modulated current input signal for generating a current control signal. The switching signal is controlled in response to the current control signal for regulating the output current, and a level of the output current is correlated to the current control signal.

Abstract: A control circuit for a programmable power supply is provided. It comprises a reference generation circuit generating a voltage-reference signal and a current-reference signal for regulating an output voltage and an output current of the power supply. A feedback circuit detects the output voltage and the output current for generating a feedback signal in accordance with the voltage-reference signal and the current-reference signal. A switching controller generates a switching signal coupled to switch a transformer for generating the output voltage and the output current in accordance with the feedback signal. A micro-controller controls the reference generation circuit. The micro-controller, the reference generation circuit, and the feedback circuit are equipped in the secondary side of the transformer. The switching controller is equipped in the primary side of the transformer. The control circuit can achieve good performance for the programmable power supply.

Abstract: A LED drive circuit according to the present invention comprises a controller and a programmable signal. The controller generates a switching signal coupled to switch a magnetic device for generating an output current to drive a plurality of LEDs. The programmable signal is coupled to regulate a current-control signal of the controller. The switching signal is modulated in response to the current-control signal for regulating the output current, and the level of the output current is correlated to the current-control signal.

Abstract: A control circuit for a programmable power supply is provided. It comprises a reference generation circuit generating a voltage-reference signal and a current-reference signal for regulating an output voltage and an output current of the power supply. A feedback circuit detects the output voltage and the output current for generating a feedback signal in accordance with the voltage-reference signal and the current-reference signal. A switching controller generates a switching signal coupled to switch a transformer for generating the output voltage and the output current in accordance with the feedback signal. A micro-controller controls the reference generation circuit. The micro-controller, the reference generation circuit, and the feedback circuit are equipped in the secondary side of the transformer. The switching controller is equipped in the primary side of the transformer. The control circuit can achieve good performance for the programmable power supply.