Richpower Microelectronics Corporation

Richtek Technology Corporation

Richpower Microelectrics Corporation

Chin-Hui Wang

Chen-Jie Ruan

Peng-Ju Lan

Liang-Pin Tai

Zheng-Lin Pu

Ying-Jie Han

Shui-Mu Lin

Ching-Yu Chen

Ti-Ti Liu

Yung-Chun Chuang

Liang Mao

Pao-Chuan Lin

Chien-Hua Lin

Hui Wang

The present invention discloses a light emitting device array billboard and a control method thereof. The light emitting device array billboard includes a light emitting device array circuit, plural line switch circuits, plural channel switch circuits, plural ghost image compensation switch circuits, and a control circuit. The control circuit operates the line switch circuits and the channel switch circuit to turn ON a selected light emitting device for a duty period in a lighting period, and operates the plural ghost image compensation switch circuits to electrically connect a channel node corresponding to the selected light emitting device to a ghost image compensation voltage after the lighting period. The control circuit further adjusts a channel operation signal according to a gray scale compensation signal, to turn ON the selected light emitting device for a gray scale compensation period in addition to the duty period.

Light emitting device array billboard and control method thereof

A state cycling apparatus uses a capacitor instead of complicated and expensive microcontroller to fulfill a state cycling function of a system. The state cycling apparatus includes an internal circuit in the system connected to the capacitor. In a first embodiment, the internal circuit reads the voltage level on the capacitor at power on to determine a current state for the system, and writes the voltage level corresponding to a next state of the system to the capacitor. In a second embodiment, the system reads the state data stored in the internal circuit to determine a current state for the system at power on, the capacitor is charged during the system is under power on, and the capacitor provides power for the internal circuit to store a state data after the system is powered off.

State cycling apparatus and method, and control circuit for a lamp

A dimming circuit and method for a LED provide a first driving voltage or a second driving voltage according to a dimming signal provided by a functional IC to enable or disable the LED. The values of the first and second driving voltages are controlled so that overstressing of the LED is avoided while the functional IC is capable of working even when the LED is off. The LED's life time is thus prolonged.

Dimming circuit and method for LEDs

A switch embedded integrated circuit for battery protection includes a first pin to be connected with one terminal of a battery, a second pin to be connected with a load or charger, a third pin to be connected with another terminal of the battery, a MOSFET having a body diode thereof and connected between the first and second pins, a control logic circuit and a detection circuit. The detection circuit monitors the voltage between the first pin and the third pin to determine a detection signal for the control logic circuit to turn on or off the MOSFET and switch the direction of the body diode, thereby providing an over charging and an over discharging protection functions.

Switch embedded integrated circuit and method for battery protection

A control circuit and method for a LED driver accurately control the output current of the LED driver by adjusting a reference voltage or a feedback voltage according to the input voltage of the LED driver such that the output current decreases with the decrease of the input voltage. Therefore, it enhances the efficiency of the LED driver and maximizes the battery use time of a battery powered system.

Control circuit and method for LED drivers

A switch embedded integrated circuit for battery protection includes a MOSFET having a body diode, and a control logic circuit for switching the MOSFET and the direction of the body diode to control the charge current to and the discharge current from a battery. The control logic circuit turns off the MOSFET once any abnormal operation such as over-voltage and under-voltage happens, and turns on the MOSFET according to an OVPR threshold, an OVPR delay time, an UVPR threshold and an UVPR delay time. The OVPR threshold and the OVPR delay time are determined depending on the battery being coupled to a load or a charger, or floating.

For a PWM controller chip in a voltage converter to switch a pair of high side and low side switches connected with a phase node therebetween, a circuit comprises a sense resistor connected between a multi-function pin on the PWM controller chip and the phase node, and an enable arrangement, a power sensing arrangement, and an over-current protection arrangement to detect the voltage on the multi-function pin for accomplishing enable function, power sensing, and over-current protection, respectively.

Circuit and method for implementing a multi-function pin on a PWM controller chip in a voltage converter

A voltage reference circuit includes a current source unit, a voltage-difference creating unit, and a resistance ratio unit. The current source unit receives an input current source and produces two current sources in equal current. The voltage-difference creating unit includes a first MOS device and a second MOS device to respectively receive the two current sources, wherein the first MOS device and a second MOS device has a threshold voltage difference. The resistance ratio unit includes a first resistor and a second resistor coupled in cascade, wherein the threshold voltage difference is applied to the first resistor. By adjusting a ratio of the first resistor to the second resistor, the resistance ratio unit produces a voltage reference, which is also fed back to the current source unit to ensure that the first current source and the second current source are equal.

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Taipei, Taiwan

Chin-Hui Wang