Optical sensor with integrated four-quarter photodiode for speed-enhancement

The large junction capacitance of photodiodes with large diameters limits both the bandwidth and the noise behavior of attached transimpedance amplifiers. With the large-area photodiode divided into four sections, the bandwidth of an optical sensor is increased from 89 MHz to 223 MHz. Simultaneously, the photosensitivity is more than doubled to 75 mV//spl mu/W.