Richpower Microelectronics Corporation

Chen-Jie Ruan

Chin-Hui Wang

Peng-Ju Lan

Liang Mao

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 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.

Growing community of inventors

Shanghai, China

Chen-Jie Ruan