O2micro International Limited

O2 Micro, Incorporated

02 Micro International Limited

Micro International Limited

02micro Inc.

2micro International Limited

Yung-Lin Lin

Da Liu

Yu-Cheng Chang

Ching-Chuan Kuo

Bingwei Yao

Naoyuki Fujita

Sheng-tai Lee

John Chou

Rong Hu

Hiroshi Yamazaki

Jen-Chun Chen

Sin-Yan Wu

Sheng-Tai Lee

A controller for controlling a light source module including a first LED array and a second LED array includes a first driving terminal and a second driving terminal. The controller is operable for turning on a switch between a power converter and the first LED array by the first driving terminal to deliver electric power from the power converter to the first LED array in a first sequence of discrete time slots, and for turning on a second switch between the power converter and the second LED array by the second driving terminal to deliver electric power from the power converter to the second LED array in a second sequence of discrete time slots, where the first sequence of discrete time slots and the second sequence of discrete time slots are mutually exclusive.

Controller for controlling a light source module

A controller includes a first sensing pin receiving a first sensing signal indicating a level of an input voltage of a resonant converter, a second sensing pin receiving a second sensing signal indicating a level of an input current of the resonant converter, a feedback pin receiving a feedback signal indicating a level of an output voltage of the resonant converter, and a first driving pin and a second driving pin controlling a high side switch and a low side switch of the resonant converter, respectively. The controller generates a compensated signal based on the first sensing signal, compares the compensated signal with a peak value of the second sensing signal to generate a first comparison result, compares the feedback signal with a threshold to generate a second comparison result, and controls the high side low side switches based on the first and the second comparison results.

Controller for controlling a resonant converter

A controller for controlling a light source module including a first LED array and a second LED array includes a power input terminal, a first power output terminal and a second power output terminal. The power input terminal is operable for receiving electric power from a power converter. The first power terminal is coupled to the first LED array, and the second power output terminal is coupled to the second LED array. The controller is operable for delivering the electric power to the first LED array via the first power output terminal in a first sequence of discrete time slots, and for delivering the electric power to the second LED array via the second power output terminal in a second sequence of discrete time slots. The first sequence of discrete time slots and the second sequence of discrete time slots are mutually exclusive.

Controller for controlling light source module

A system for driving a light source includes a power converter and control circuitry coupled to the power converter. The power converter converts input power to an output voltage to power the light source. The control circuitry senses the output voltage and senses current of the light source. The control circuitry generates a control signal based on a voltage feedback signal indicative of a combination of said output voltage and said current of said light source, and controls the power converter by the control signal to adjust the output voltage.

System and method for driving light source comprising voltage feedback circuit and current feedback circuit

A driving circuit includes a power converter, a dimming controller and a current path coupled to the dimming controller. The power converter receives input power from a rectifier and provides output power to a light source. A power switch transfers power from an AC power source to the rectifier when the power switch is on. The dimming controller receives a switch monitoring signal indicative of the state of the power switch. An average current flowing through the light source has a first value if the power switch is on. The dimming controller is operable for adjusting the average current based on the switch monitoring signal. A current flows from the AC power source through the current path to ground when the power switch is off.

Driving circuit with dimming controller for driving light sources

A method according to one embodiment may include supplying power to an LED array having at least a first string of LEDs and a second string of LEDs coupled in parallel, each of the strings includes at least two LEDs. The method of this embodiment may also include comparing a first feedback signal from the first string of LEDs and a second feedback signal from the second string of LEDs. The first feedback signal is proportional to current in said first string of LEDs and said second feedback signal is proportional to current in said second string of LEDs. The method of this embodiment may also include controlling a voltage drop of at least the first string of LEDs to adjust the current of the first string of LEDs relative to the second string of LEDs, based on, at least in part, the comparing of the first and second feedback signals. Of course, many alternatives, variations, and modifications are possible without departing from this embodiment.

Controller circuitry for light emitting diodes

A controller for controlling dimming of an LED light source includes a control terminal and dimming control circuitry coupled to the control terminal. The control terminal provides a driving signal to control a control switch coupled to the LED light source, thereby controlling the dimming of the LED light source. The dimming control circuitry generates the driving signal according to a set of operations of a power switch that transfers an AC signal. The dimming control circuitry further adjusts the driving signal by counting multiple waves of the AC signal to control the dimming of the LED light source.

Controllers, systems and methods for controlling dimming of light sources

A dimming controller for controlling dimming of a light-emitting diode (LED) light source includes a monitoring terminal and a control terminal. The monitoring terminal receives a switch monitoring signal indicative of an operation of a power switch which transfers power from an AC power source to a bridge rectifier when the power switch is on. A power converter receives input power from the bridge rectifier and provides output power to the LED light source. The control terminal generates a control signal to adjust the output power according to the switch monitoring signal so as to control dimming of the LED light source.

A power supply system is provided for a multiple lamp LCD panel. In one aspect, the power supply includes a plurality of transformers for driving a plurality of respective CCFLs. The primary sides of each transformer are coupled in series to thereby reduce the stress on each transformer. For LCD panels that include longer CCFLs, a power supply is provided that includes a plurality of transformers for driving a plurality of respective CCFLs. The primary sides of each transformer are coupled in series and each lamp is coupled to two secondary sides of the transformers, thereby reducing the problems associated with longer CCFL tubes. In any of the embodiments, the power supply can be adapted to convert a high voltage DC signal to high voltage AC used to power the lamps.

Power supply for an LCD display

A method according to one embodiment may include providing power to at least one light source. The method of this embodiment may also include detecting the frequency of at least one vertical synchronization signal, among a plurality of different synchronization signals, and controlling the power to at least one light source based on, at least in part, the detected frequency of at least one vertical synchronization signal. Of course, many alternatives, variations, and modifications are possible without departing from this embodiment.

Integrated circuit capable of synchronization signal detection

A driving circuit for controlling power of a light source includes a power converter coupled to a power source and the light source, and a dimming controller coupled to the power converter. The power converter can receive power from the power source and provide a regulated power to the light source. The power converter includes a control switch coupled in series with the light source. The dimming controller can monitor a power switch coupled between the power source and the driving circuit, and receive a dimming request signal and a dimming termination signal. The dimming request signal can indicate a first set of operations of the power switch. The dimming termination signal can indicate a second set of operations of the power switch. The dimming controller can continuously adjust the regulated power from the power converter by controlling the control switch if the dimming request signal is received, and can stop adjusting the regulated power from the power converter if the dimming termination signal is received.

Driving circuit with continuous dimming function for driving light sources

In one embodiment, the present disclosure provides a method to control the brightness of a display. One exemplary method includes generating a signal indicative of a display brightness level, and controlling the brightness of the display, based at least in part on the signal indicative of a display brightness level.

Brightness control system

There is provided a driving circuit for powering a plurality of light sources. The driving circuit includes a power converter, a plurality of switching regulators and a plurality of switching balance controllers. The power converter is operable for receiving an input voltage and for providing a regulated voltage to the light sources. The switching regulators are operable for adjusting forward voltages of the light sources respectively. The switching balance controllers are operable for generating pulse modulation signals to control the switching regulators respectively.

Driving circuit for powering light sources

A method according to one embodiment may include generating, by a controller, a plurality of control signals to control operations of inverter circuitry to generate an AC signal from a DC signal. The method of this embodiment may also include using the control signals generated by the controller to also control operations of power factor correction (PFC) circuitry, via the inverter circuitry, to enable the PFC circuitry to generate power factor correction of an input source coupled to the PFC circuitry and the inverter circuitry. Of course, many alternatives, variations, and modifications are possible without departing from this embodiment.

Growing community of inventors

Palo Alto, CA, United States of America

Yung-Lin Lin