Abstract: A design of multi-channel Mach-Zehnder modulator driver aiming at high-density integration is proposed in this paper, the single-channel circuits consists of signal equalizer, clock tree, delay control module, output swing control module and other amplifying components, supporting delay-tunable 25GHz high-speed differential clock signals, swing-tunable differential outputs, and up to 25 Gbps NRZ digital signal transmission. Based on TowerJazz 0.18 μm SiGe BiCMOS technology, the driver chip consists of 6 individual channels, with a bandwidth of 17.2 GHz, a maximum output swing of 3Vppd and an jitter of 8.9 ps. The chip consumes 646.9 mW from a dual power supply of 2.3/3.6V.