Abstract: A power switch device driver with energy recovery is discussed. The power switch device adopts four switches and one inductor with appropriate control to insure the switching speed and save the power loss.

Abstract: A drive circuit configured to drive a power stage including a high voltage power switch device. The drive circuit has a transmitter configured to send a control signal, and a receiver configured to transfer a received signal to a drive signal by a first isolated capacitor loop and a second isolated capacitor loop. The first isolated capacitor loop has a same area as the second isolated capacitor loop.

Abstract: A power switch device driver with energy recovery is discussed. The power switch device adopts four switches and one inductor with appropriate control to insure the switching speed and save the power loss.

Abstract: A control circuit having: a logic circuit, configured to provide a high side boot-strap capacitor control signal set and a low side boot-strap capacitor control signal set; a high side boot-strap capacitor control circuit, configured to provide a high side power signal to control a high side power switch; a high side boot-strap capacitor, having a first terminal coupled to a control terminal of the high side power switch, and a second terminal coupled to the high side boot-strap capacitor control circuit; a low side boot-strap capacitor control circuit, configured to provide a low side power signal to control a low side power switch; and a low side boot-strap capacitor, having a first terminal coupled to a control terminal of the low side power switch, and a second terminal coupled to the low side boot-strap capacitor control circuit.

Abstract: A control circuit having: a logic circuit, configured to provide a high side boot-strap capacitor control signal set and a low side boot-strap capacitor control signal set; a high side boot-strap capacitor control circuit, configured to provide a high side power signal to control a high side power switch; a high side boot-strap capacitor, having a first terminal coupled to a control terminal of the high side power switch, and a second terminal coupled to the high side boot-strap capacitor control circuit; a low side boot-strap capacitor control circuit, configured to provide a low side power signal to control a low side power switch; and a low side boot-strap capacitor, having a first terminal coupled to a control terminal of the low side power switch, and a second terminal coupled to the low side boot-strap capacitor control circuit.

Abstract: A resonant converter includes: a rectifier bridge; a first capacitor coupled across output terminals of the rectifier bridge; a diode with its anode coupled to a first terminal of the first capacitor; a second capacitor with a first terminal coupled to the cathode of the diode, and a second terminal coupled to a second terminal of the first capacitor; a first transistor having a first terminal coupled to the first terminal of the second capacitor; a second transistor having a first terminal coupled to a second terminal of the first transistor, and a second terminal coupled to the second terminal of the first capacitor; a resonant tank having a first input terminal coupled to the first terminal of the first capacitor, and a second input terminal coupled to the second terminal of the first transistor and the first terminal of the second transistor; and a rectifying and filtering circuit coupled across output terminals of the resonant tank, and configured to provide an output signal to a load.

Abstract: A two-channel LED driver with short circuit protection is discussed. A short process circuit monitors a short condition of the LED driver, and locks the short status if short circuit occurs at either one of or both of the channels.

Abstract: A resonant converter includes: a rectifier bridge; a first capacitor coupled across output terminals of the rectifier bridge; a diode with its anode coupled to a first terminal of the first capacitor; a second capacitor with a first terminal coupled to the cathode of the diode, and a second terminal coupled to a second terminal of the first capacitor; a first transistor having a first terminal coupled to the first terminal of the second capacitor; a second transistor having a first terminal coupled to a second terminal of the first transistor, and a second terminal coupled to the second terminal of the first capacitor; a resonant tank having a first input terminal coupled to the first terminal of the first capacitor, and a second input terminal coupled to the second terminal of the first transistor and the first terminal of the second transistor; and a rectifying and filtering circuit coupled across output terminals of the resonant tank, and configured to provide an output signal to a load.

Abstract: A two-channel LED driver with short circuit protection is discussed. A short process circuit monitors a short condition of the LED driver, and locks the short status if short circuit occurs at either one of or both of the channels.

Abstract: A LED driver adopts one power stage to provide a constant drive current to drive a load, and to provide different power supply voltages to power a smart module according to a dimming signal input by users through the smart module. The LED driver provides high performance with simple circuit structure.

Abstract: A two-channel LED driver adopts one power stage to provide a constant drive current to drive a first channel LED and a second channel LED, and to provide a power supply voltages to power a smart module. The two-channel LED driver controls the total current flowing through the first channel LED and the second channel LED according to a first dimming signal input by users through the smart module, and controls the dimming ratio between the two channels according to a second dimming signal. The two-channel LED driver provides high performance with simple circuit structure.

Abstract: A LED driver adopts one power stage to provide a constant drive current to drive a load, and to provide different power supply voltages to power a smart module according to a dimming signal input by users through the smart module. The LED driver provides high performance with simple circuit structure.

Abstract: A two-channel LED driver adopts one power stage to provide a constant drive current to drive a first channel LED and a second channel LED, and to provide a power supply voltages to power a smart module. The two-channel LED driver controls the total current flowing through the first channel LED and the second channel LED according to a first dimming signal input by users through the smart module, and controls the dimming ratio between the two channels according to a second dimming signal. The two-channel LED driver provides high performance with simple circuit structure.

Abstract: A method of capacitive mode detection is used in a resonant converter. The resonant converter has a square wave generator having a first switch and a second switch, a resonant network, an isolated transformer having a primary winding and a second winding, and a rectifier network providing an output DC voltage for a load. The method of capacitive mode detection includes: detecting a voltage of the secondary winding and generating a voltage detection signal; detecting an output DC voltage of the rectifier network and generating a voltage detecting threshold; comparing the voltage detection signal with the voltage detection threshold when either of the first and the second switches is turned OFF; generating a flag signal indicating whether the resonant converter enters into a capacitive mode based on the comparison result.

Abstract: A primary control LED driver includes: a switching converter having a main switch and a first winding, and configured to provide an LED driving current; a second winding magnetically coupled to the first winding and configured to provide a power supply voltage at a first terminal; a first sensing resistor with a first terminal coupled to the main switch; a second sensing resistor with a first terminal coupled to the second terminals of the first sensing resistor and the second winding; an output current calculator calculating an equivalent value of the LED driving current based on the voltage at the first terminal of the first sensing resistor; an error amplifier configured to generate a compensation signal based on the equivalent value and a reference voltage; and a control circuit generating a control signal to control the main switch based on the compensation signal.

Abstract: A switching regulator uses an over voltage comparator to compare an envelop line signal with a reference wave signal, to detect whether the system is in an over voltage condition. The envelop line signal is indicative of a peak value of an inductor current.

Abstract: A ripple suppression circuit has a filter circuit and a follower circuit. The filter circuit has a first input terminal coupled to a signal source to receive a ripple signal and an output terminal to output a filter signal which is the sum of the average value of the ripple signal and a positive bias signal. The follower circuit has a first input terminal, a second input terminal and an output terminal, wherein the first input terminal is coupled to the signal source to receive the ripple signal, the second input terminal is coupled to the output terminal of the filter circuit to receive the filter signal, the follower circuit provides an output signal at the output terminal, the output signal at least partially follows the filter signal.

Abstract: A LED driver, a LED driving method and a controller for LED driver are discussed in the present invention. The LED driver detects the phase of the input signal which is phase cut by a triac from a pre-E-transformer. The LED driver regulates the current flowing through the LED strings by varying the phase of the input signal.

Abstract: A voltage detecting circuit used with a switching converter. The switching converter having an energy storage component, a first power switch and a second switch. The voltage detecting circuit has a sample and hold circuit configured to sample and hold the voltage at the connection node of the energy storage component and the first power switch when the first power switch is OFF and the second power switch is ON; and an average circuit configured to average the sampled voltage during a switching period to generate a detecting signal in proportional to the output voltage of the switching converter.

Abstract: A power supply system has a current source configured to provide an output current, a load supplied by the current source, and a current ripple suppression circuit. The current ripple suppression circuit has a first end and a second end, wherein the first end of the current ripple suppression circuit is coupled to the load, and the second end of the current ripple suppression circuit is coupled to a reference ground; wherein the current ripple suppression circuit is configured to suppress the current ripple in the output current and adaptively adjust the output current of the current source at a predetermined current level.