In this work, a 12.5-Gb/s trans-impedance amplifier (TIA) with capacitive peaking, limiting amplifier (LA) based on the Cherry-Hooper amplifier, and high-voltage laser/modulator driver are proposed in 0.13-μm CMOS process. The TIA and the LA operate without any inductors, and the TIA achieves a trans-impedance gain of 52.9-dBΩ and a bandwidth of 14.3GHz. The TIA and the LA use the negative Miller effect to extend the bandwidth without using any inductors. The core layout occupies an area of only 35*150 μm². The laser/modulator driver of the transmitter drives the capacitance of the Mach-Zehnder modulator which contributes around 1.2pF. Using only thin MOS devices, the output swing of the driver exceeds 2.4V. The measurement results show the overall operating speed of 12.5-Gb/s.