Abstract: A light modulator includes a substrate, a first semiconductor structure, a second semiconductor structure and a dielectric structure. The substrate has a principal surface and a first direction substantially perpendicular to the principal surface. The first semiconductor structure has a first conductive type and disposed over the principal surface. The second semiconductor structure has a second conductive type and disposed over the principal surface, in which the second semiconductor structure is free from overlapping the first semiconductor structure in the first direction. The dielectric structure is disposed over the principal surface and extends upwards from the principal surface such that dielectric structure is interposed between the first semiconductor structure and the second semiconductor structure.

Abstract: A driving device for a LED module is provided. The driving device for the LED module includes a voltage converting unit, a LED module voltage detecting unit, and a switching signal generation unit. The voltage converting unit produces a driving voltage to drive the LED module according to a switching signal. The LED module voltage detecting unit divides the driving voltage to produce a comparison voltage. The switching signal generation unit receives the comparison voltage by a fault detection pin and compares a reference voltage and the comparison voltage to enable or disable the switching signal. After the switching signal is disabled, the switching signal generation unit further pulls up a voltage level of the fault detection pin to a logic high level voltage, so as to produce a fault notification signal to let the fault detection pin also have a function for fault notification.

Abstract: A flyback voltage converter includes a transformer having a primary winding and a secondary winding, a switch serially connected to the primary winding for being switched to produce a current in the secondary winding, and a negative lock loop to adjust the peak value of the current in the secondary winding according to a current conduction time during which the current in the secondary winding is higher than a current threshold, such that the peak value of the current in the secondary winding will be in inverse proportion to the time.

Abstract: A driving device for a LED module is provided. The driving device for the LED module includes a voltage converting unit, a LED module voltage detecting unit, and a switching signal generation unit. The voltage converting unit produces a driving voltage to drive the LED module according to a switching signal. The LED module voltage detecting unit divides the driving voltage to produce a comparison voltage. The switching signal generation unit receives the comparison voltage by a fault detection pin and compares a reference voltage and the comparison voltage to enable or disable the switching signal. After the switching signal is disabled, the switching signal generation unit further pulls up a voltage level of the fault detection pin to a logic high level voltage, so as to produce a fault notification signal to let the fault detection pin also have a function for fault notification.

Abstract: The phase node voltage or the PWM signal in an asynchronous boost converter is monitored to detect a phase node voltage ringing. When a phase node voltage ringing is detected, a detection signal is asserted to establish a bypass path to bypass the inductor of the converter. A charge bypass circuit is shunt to the inductor, and controlled by the detection signal to establish the bypass path. Due to the bypass path, the phase node voltage is maintained at a constant, and the phase node voltage radiation and input/output noise are eliminated.

Abstract: The present invention discloses a half-voltage headphone driver circuit, comprising: at least one operational amplifier providing an output to a headphone speaker, and a charge pump receiving a supply voltage (VDD), generating a positive half-voltage and a negative half-voltage (VDD/2 and ?VDD/2) based on the supply voltage, and supplying the positive half-voltage and negative half-voltage as high and low operation levels to the at least one operational amplifier.

Abstract: A class AB output stage includes a driver to generate a first drive signal and a second drive signal, and two bias voltage sources to provide two bias voltages to level shift the first and second drive signals, in order to drive a pair of high side and low side transistors, respectively. A control circuit provides a control signal to adjust the first and second bias voltages, so as to shift the bias point of the class AB output stage. The control signal is determined according to the currents in the high side and low side transistors and a programmable parameter. By adjusting the parameter, the bias point deviation can be removed to obtain both low quiescent current and best THD performance.

Abstract: For protecting a power system, two or three of over current, thermal and under voltage protection circuits are integrated as one protection circuit but operate independently, and one or more protection points thereof are adjusted dynamically in response to detected condition of the power system. Specifically, using voltage and current conditions in the power system to modify the over current protection and the thermal protection maximizes the performance of the power system and covers the process bias in the circuits.

Abstract: The present invention discloses a load-dependent frequency jittering circuit, comprising: a load condition detection circuit for receiving a switching signal and generating an output according to a load condition; a number generator for receiving the output of the load condition detection circuit and generating a number; a digital to analog converter for converting the output of the number generator to an analog signal; and an oscillator for generating a jittered frequency according to the output of the digital to analog converter.

Abstract: A flyback voltage converter includes a transformer having a primary winding and a secondary winding, a switch serially connected to the primary winding for being switched to produce a current in the secondary winding, and a negative lock loop to adjust the peak value of the current in the secondary winding according to a current conduction time during which the current in the secondary winding is higher than a current threshold, such that the peak value of the current in the secondary winding will be in inverse proportion to the time.

Abstract: A linear voltage regulator comprises a transistor for converting a supply voltage to an output voltage. By directly monitoring the supply voltage and thereby rapidly responding when the supply voltage suffers a ripple, the linear voltage regulator enhances the stability of the output voltage.

Abstract: Time-sharing technique is used for power conversion to improve the thermal dissipation thereof. In a power supply arrangement to provide a supply voltage to a load, a plurality of linear regulators are so switched that each time only one of them is enabled to convert an input voltage to the supply voltage, thereby each of them suffering less thermal dissipation.

Abstract: A class AB output stage includes a driver to generate a first drive signal and a second drive signal, and two bias voltage sources to provide two bias voltages to level shift the first and second drive signals, in order to drive a pair of high side and low side transistors, respectively. A control circuit provides a control signal to adjust the first and second bias voltages, so as to shift the bias point of the class AB output stage. The control signal is determined according to the currents in the high side and low side transistors and a programmable parameter. By adjusting the parameter, the bias point deviation can be removed to obtain both low quiescent current and best THD performance.

Abstract: A flyback converter has a controller to switch a power switch so as to convert an input voltage to an output voltage for a load by monitoring an output voltage dependent signal and a current sensing signal derived from a current flowing through the power switch, a light-load efficiency improving apparatus monitors the load and a supply voltage provided for the controller to selectively clamp the output voltage dependent signal when the load is lower than a first threshold value and the supply voltage is lower than a second threshold value, so as to increase the supply voltage.

Abstract: A frequency jittering control circuit wherein by means of the characteristics of a PLL whose input switches between different frequencies, the output frequency of the PLL swings between the different frequencies to achieve the desired frequency jittering.

Abstract: A control device, which controls a power-converting module that is coupled to a light-emitting component, includes a duration detecting unit and a control signal generator. The duration detecting unit compares the duration of a predetermined logic state of a pulsating input dim control signal with a reference time period. The control signal generator is enabled by the duration detecting unit so as to generate a control signal that enables the power-converting module to generate a drive voltage for driving the light-emitting component when the duration of the predetermined logic state is not longer than the reference time period. The duration detecting unit disables the control signal generator to disable the power-converting module when the duration of the predetermined logic state is longer than the reference time period.

Abstract: For protecting a power system, two or three of over current, thermal and under voltage protection circuits are integrated as one protection circuit but operate independently, and one or more protection points thereof are adjusted dynamically in response to detected condition of the power system. Specifically, using voltage and current conditions in the power system to modify the over current protection and the thermal protection maximizes the performance of the power system and covers the process bias in the circuits.

Abstract: The present invention discloses a load-dependent frequency jittering circuit, comprising: a load condition detection circuit for receiving a switching signal and generating an output according to a load condition; a number generator for receiving the output of the load condition detection circuit and generating a number; a digital to analog converter for converting the output of the number generator to an analog signal; and an oscillator for generating a jittered frequency according to the output of the digital to analog converter.

Abstract: For protecting a power system, two or three of over current, thermal and under voltage protection circuits are integrated as one protection circuit but operate independently, and one or more protection points thereof are adjusted dynamically in response to detected condition of the power system. Specifically, using voltage and current conditions in the power system to modify the over current protection and the thermal protection maximizes the performance of the power system and covers the process bias in the circuits.

Abstract: The present invention discloses a charge pump start up circuit comprising: a start up transistor having one end which is electrically connected with a voltage supply source, and another end which is electrically connected to a voltage node; and a charge pump circuit having an input which is electrically connected with the voltage node, and an output which is electrically with the gate of the start up transistor.