A wide-swing optical modulator driver is implemented in 0.13-mu m SiGe-BiCMOS using a three-stage distributed amplifier with a digital input line. Measurements demonstrate 6-Vp-p differential output, symmetric 6-ps (min) rise/fall times, 333-fs (rms) additive jitter, and better than 20-dB output return loss (S-11) below 58 GHz. Full output swing with adjustable (6-12 ps) rise/fall times is realized after a three-step calibration sequence facilitated by an on-chip energy detector and digital control. The circuit supports 28-48-Gb/s external data sources, or 2(11) -1 PRBS and 1-0 internal data generators for calibration and characterization respectively. The 3-mm(2) driver IC (1.8-mm(2) active area) consumes 1.92 W from + 5/-2.5-V supplies.