An integrated lighting unit with regulated pulse current driving technique

This paper proposes an integrated lighting unit using the regulated pulse current driving (RPCD) technique for low power application. On-chip/package integration of a white LED with a LED driver, also named a lighting unit in this paper, may be ideal for smaller and lighter portable devices. The integrated lighting unit is connected to a pulse current driver fabricated with the complementary metal-oxide semiconductor technology (CMOS) and a white LED on chip integration. Such a combination would help reduce the size of the device and thus packaging costs. Two control signals are used in the proposed driver to modulate the pulse current. One signal modulates the amplitude of pulse current between 100 and 500mA and the other modulates the pulse current frequency between the range of 350kHz and 750kHz. The dimming method and experiments on the prototype of the lighting unit has been built and measured. The active area of the designed chip is 0.64mm×0.56mm in a 0.5μm CMOS process. The resulting integrated lighting unit works well therefore this compact device is suitable for portable applications.