A 40 Gbps Micro-Ring Modulator Driver Implemented in a SiGe BiCMOS Technology

This paper presents a 40 Gbps micro-ring modulator driver IC implemented in a 130nm SiGe BiCMOS technology providing a fT,max of 250GHz. The proposed bandwidth-optimized driver IC achieves 2Vppd output signal swing required for the integrated high-impedance silicon photonics ring modulator or 1Vppd when differentially terminated with 100Ω. The complete driver including input termination and biasing consumes 90mW operated from a single 2:5V power supply. The inductor-less driver architecture exploits a current density optimized cascode topology with capacitive degeneration to improve both, the overall bandwidth and the output voltage swing. The driver core occupies only 0.04mm2. Small-signal measurements show a differential gain of 16dB with a -3dB bandwidth of 33GHz and a return loss of -15dB at 33GHz. This design represents one of the fastest micro-ring modulator drivers with FOM of 2.25 pJ/(bit×⌉Vppd) above 25 Gbps.