Design of a Radio Frequency LVPECL Fanout Driver for Low Jitter Clock Distribution Systems

Low jitter clock distribution plays a critical role in improving system performance, especially in multi-channel data conversion systems. A radio frequency temperature-robust fanout driver with two pin selectable inputs, twelve LVPECL Outputs is presented. Compared to previously reported LVPECL drivers with the same function, the proposed driver achieves higher bandwidth and lower addictive phase noise. The prototype chip realized in 180nm SiGe process shows that the maximum operating frequency is 7. 5GHz, given supply voltage 3. 3V. The measured addictive phase noise results are - 135.33dBc/Hz@l0Hz, -156.56dBc/Hz@1MHz respectively, at carrier frequency of 622. 08MHz. The addictive jitter is 21fs RMS when integrated from 10 kHz to 20MHz, at carrier frequency of 1GHz. The maximum output-to-output skew is 30ps and the propagation delay is 80ps tested at 25°C.