92% start-up time reduction by variation-tolerant chirp injection (CI) and negative resistance booster (NRB) in 39MHz crystal oscillator

To reduce the start-up time of a crystal oscillator (XO), a chirp injection (CI) and a negative resistance booster (NRB) are proposed. By combining CI and NRB, the measured start-up time of a 39-MHz XO in 180-nm CMOS is reduced by 92% from 2.1ms to 158μs, which is the shortest time in the published XO´s. The measured start-up time variations due to the ±20% supply voltage change or the temperature change are less than 13%.