A 13-Bit 9GS/s RF DAC-based broadband transmitter in 28nm CMOS

A 13-bit current-steering DAC-based transmitter prototype is integrated into a 28nm CMOS SoC for broadband communication systems. The DAC uses a segmented structure with a focus on high speed, low noise, and low distortion. A novel LDO is also proposed for better spur tolerance in hostile SoC environments. The transmitter achieves > 70dBc SNDR within the 50-1000MHz cable band for single QAM channel transmission at 1GHz. The DAC can run up to 9GS/s with IM3 > 45dBc up to 4.4GHz. It consumes 360mW with a 1.8V supply and a footprint of 1.16mm2.