Title :
A low-phase-noise 0.004ppm/step DCXO with guaranteed monotonicity in 90nm CMOS
Author_Institution :
Texas Instrum. Inc., Plano, TX, USA
Abstract :
A 26MHz DCXO achieves phase noise of -140dBc/Hz at 1 kHz, -152dBc/Hz at 10kHz offset, and supply pushing of 0.5ppm/V. Frequency tuning is done by a pre-distorted 14b MOS capacitor DAC. Monotonicity of ∼0.004ppm/step across the entire 70ppm tuning range is guaranteed by a ΔΣ modulation scheme. The circuit occupies 0.18mm2 in 90nm CMOS.
Keywords :
CMOS integrated circuits; circuit tuning; crystal oscillators; delta-sigma modulation; digital-analogue conversion; phase noise; ΔΣ modulation; 26 MHz; 90 nm; CMOS; frequency tuning; guaranteed monotonicity; low-phase-noise DCXO; pre-distorted 14b MOS capacitor DAC; Automatic frequency control; Decoding; Instruments; Inverters; MIM capacitors; MOS capacitors; Oscillators; Phase noise; Threshold voltage; Tuning;
Conference_Titel :
Solid-State Circuits Conference, 2005. Digest of Technical Papers. ISSCC. 2005 IEEE International
Conference_Location :
San Francisco, CA
Print_ISBN :
0-7803-8904-2
DOI :
10.1109/ISSCC.2005.1494047
