Design of CMOS LED driver and optical receiver for 650-nm POF applications

In this paper, LED driver and optical receiver for 650-nm plastic optical fiber (POF) applications are designed and implemented using 0.5-mum CMOS technology. In LED driver, modulation current has to be arranged in 3 to 4-mA to meet eye protection regulations in visible red wavelength (650-nm). To apply for low cost POF applications, simple and low cost LED driver is proposed. LED driver is designed to operate at 50-Mb/s bit rates and consumes only 6-mA DC currents including modulation current of 3.5-mA. In the receiver side, two methods of auto-threshold control technique will be introduced and compared. The designed optical receiver achieves transimpedance gain of 145-dBOmega, 50-Mb/s operations with 45-MHz bandwidth for 4-pF photodiode parasitic capacitance. And proposed optical receiver guarantees digital level output swing against the range of incident photo current from 200-nA to 25-uA and the range of operating frequency from DC to 50-Mb/s. Receiver chipset consumes only 10-mW from a 3.3-V single supply.