Title :
A digitally temperature-compensated crystal oscillator with minimized phase-shifts
Author :
Moh, Kyung-goo ; Nam, Jong-ki ; Koh, Hwa-su ; Kim, Taek-moo ; Sohn, Jang-sub ; Eum, In-hwan ; Yoon, Hoon-mo ; Yoon, Byung-chun ; Hwang, Dong-hyuk ; Kim, Jong-shik
Author_Institution :
R&D Div., Innosign Co. Ltd, Seoul, South Korea
Abstract :
The phase shifts in the output signal, due to discrete nature of the load capacitance, have been analyzed for a Digitally Temperature Compensated Crystal Oscillator (DTCXO) with on-chip capacitor-switch arrays. Also a one-chip DTCXO with minimized phase shifts has been fabricated on a standard 0.25 μm CMOS process. The effect of phase shifts is minimized by employing charge-pump circuits. This shows a trimming accuracy of about 0.2 ppm, which is not degraded by process variations.
Keywords :
CMOS analogue integrated circuits; compensation; crystal oscillators; 0.25 micron; charge-pump circuits; digitally temperature-compensated crystal oscillator; load capacitance; minimized phase shifts; on-chip capacitor-switch arrays; phase-jump phenomena; single-chip DTCXO; submicron CMOS process; CMOS process; Capacitance; Charge pumps; Degradation; Digital-controlled oscillators; Frequency; Phased arrays; SPICE; Switches; Switching circuits;
Conference_Titel :
Frequency Control Symposium and PDA Exhibition, 2002. IEEE International
Print_ISBN :
0-7803-7082-1
DOI :
10.1109/FREQ.2002.1075952
