A 100-Gb/s PAM-4 Optical Receiver With 2-Tap FFE and 2-Tap Direct-Feedback DFE in 28-nm CMOS

Optical receivers (ORXs) with integrated CMOS electronics enable compact, low-power solutions for 400-G Ethernet and co-packaged optics. In this article, we present a 100-Gb/s PAM-4 ORX with TIA and sampler integrated into a single 28-nm CMOS IC. ORX sensitivity is optimized using a low noise, sub-Nyquist bandwidth TIA followed by a mixed signal sampler that includes 2-tap FFE and 2-tap DFE. A dis...