[IEEE 2017 IEEE Nordic Circuits and Systems Conference (NORCAS): NORCHIP and International Symposium of System-on-Chip (SoC) - Linkoping (2017.10.23-2017.10.25)] 2017 IEEE Nordic Circuits and Systems Conference (NORCAS): NORCHIP and International Symposium of System-on-Chip (SoC) - A 1.8mW 450-900MHz ±15ps period jitter programmable multi-output clock generator with high supply noise tolerance in 28-nm CMOS process