High-Dynamic-Range Photodetecting Scheme Based on PEPT With a Large Output Swing

In this paper, we demonstrate a novel photodetecting scheme featuring intrinsic high dynamic range (DR) and large output voltage swing. Employing an optimized punchthrough enhanced phototransistor (PEPT), a large output swing of over 1 V and a high DR of more than 140 dB are achieved without any auxiliary amplifier. Fabricated with 0.5-μm low-cost standard CMOS process, the operating voltage of the photodetecting system can be as low as 1.8 V. Comprehensive theoretical analyses on PEPT are presented as well as corresponding measurement results.