A CMOS infrared optical signal processor for remote control

A CMOS infrared OSP (Optical Signal Processor) for remote control is presented in this paper. Usually, the infrared OSP was fabricated using bipolar or BiCMOS process because the noise performance of BIT device is better than that of MOS device. In this paper, a low noise CMOS OSP with transient noise simulation is proposed. Designed OSP is composed of pre-amplifier with variable gain, band-pass filter, noise level detector, and output signal shaper. A pre-amplifier converts the current signal from photo-diode to voltage signal, and amplifies converted voltage signal with variable gain. The gain is controlled by the noise level. A band-pass filter attenuates the noise signal from internal device or external light sources. A noise level detector detects the noise level of filtered signal, and controls the gain of variable gain amplifier. The output signal of OSP is generated from signal shaper. Designed OSP is fabricated using 0.5 mum CMOS process and it occupies smallest size of 0.9 mm x 0.7 mm among present OSPs. And it consumes low power of 1.5 mW at 3 V single supply.