此參考設(shè)計(jì)可實(shí)現(xiàn)并測(cè)量完整的120 mhz高帶寬光學(xué)前端;這種前端由高速跨阻放大器、全差動(dòng)放大器和高速160位議員ADC（具有JESD204B接口）組成。設(shè)計(jì)中提供了相應(yīng)的硬件和軟件，用于評(píng)估該系統(tǒng)對(duì)于隨附激光驅(qū)動(dòng)器和二極管產(chǎn)生的高速光脈沖的響應(yīng)性能，適合具有光時(shí)域反射（OTDR））的應(yīng)用。

　　A high-speed laser driver pulses the laser diode that transmits an optical pulse through the fiber. The optical attenuator controls the strength of the optical pulse incident on the photo-diode without changing the operating point of the laser diode or its driver. A high-speed photodiode placed in close proximity to the transimpedance amplifier converts the optical energy into an output current. The transimpedance amplifier converts the current into a pseudo-differential output voltage. The subsequent fully differential amplifier （FDA） stage converts the signal to a fully differential signal and level-shifts the output commonmode to match the ADC. The FDA drives the ADC through a doubly terminated 50-? resistor.