Abstract-Highly integrated electronic driver and receiver ICs with low power consumption are essential for the development of cost-effective multi-channel fiber-optic transceivers with small form factor. This paper presents the latest results of a twochannel 28 Gbit/s driver array for optical duobinary modulation and a four-channel 25 Gbit/s TIA array suited for both NRZ and optical duobinary detection. This research demonstrated that 28 Gbit/s duobinary signals can be efficiently generated on chip with a delay-and-add digital filter and that the driver power consumption can be significantly reduced by optimizing the drive impedance well above 50 Ω, without degrading the signal quality. To the best of our knowledge this is the fastest modulator driver with on-chip duobinary encoding and precoding, consuming only 652 mW per channel at a differential output swing of 6 Vpp. The 4 × 25 Gbit/s TIA shows a good sensitivity of −10.3 dBm average optical input power at 25 Gbit/s for PRBS 2 31 − 1 and low power consumption of 77 mW per channel. Both ICs were developed in a 130 nm SiGe BiCMOS process.