A 185-μW, 40-MHz TCXO With a Differential-Pair-Based Polynomial Temperature Compensation Technique Achieving <±2.5 ppm Frequency Error
Journal
IEEE Journal of Solid-State Circuits
Start Page
1
End Page
11
ISSN
0018-9200
1558-173X
Date Issued
2025-11-04
Author(s)
Fang, Chia-Hsi
Lin, Chun-Yu
Chien, Hung-Che
Yang, Shuan
Tsou, Shan-Chih
Wen, Shon-Hang
Chen, Kuan-Dar
Abstract
This article presents a 40-MHz temperature-compensated crystal oscillator (TCXO) incorporating a differential-pair-based (DPB) technique for compensating the temperature-dependent frequency error. By configuring three differential pairs to synthesize a cubic input–output polynomial characteristic, the proposed circuit generates a temperature-dependent voltage to control a single varactor, efficiently compensating for the cubic frequency error intrinsic to the crystal device. Fabricated in a TSMC 90-nm CMOS process, a 40-MHz TCXO with the proposed technique is demonstrated. This TCXO occupies an active area of 0.455 mm2 and achieves <±2.5 ppm frequency error over the -40°C ~80°C temperature range. The phase noise (PN) of TCXO is −117.5dBc/Hz at 10-kHz offset with 4.5 psec_rms integrated jitter. TCXO consumes 185 µW, while the temperature-compensation blocks consume only 16% of the overall power.
Subjects
Analog temperature-compensated crystal oscillator (TCXO)
Crystal oscillator (XO)
temperature compensation
varactor
SDGs
Publisher
Institute of Electrical and Electronics Engineers Inc.
Type
journal article