A new small-sized pierce crystal oscillator readout with novel on-chip all-digital temperature sensing and compensation

Hsuan Wen Peng, Chung Hsin Su, Chang-Po Chao, Jing Wen Hsieh, Chun Kai Chang

Research output: Contribution to journalConference articlepeer-review

1 Scopus citations

Abstract

This paper presents a 16-MHz digital-controlled crystal oscillator and a time-domain temperature sensor design to achieve a high precision temperature-compensated crystal oscillator in a low-power mobile device. The digital-controlled crystal oscillator is based on Pierce topology with two 8-bit switched-capacitor arrays and the temperature of it is measured by time-domain temperature sensor. For noise reduction, the supply voltages of digital-controlled crystal oscillator and time-domain temperature sensor are regulated at 1.2 V by using two on-chip low-dropout regulators. The proposed circuit design has been successfully fabricated by using TSMC 0.18-μm CMOS process, where the active area is 0.516 mm2. The measured startup time of fabricated 8-bit digital-controlled crystal oscillator is about 0.35 ms and the measured phase noise of 1 kHz offset at 25°C is -119.93 dB/Hz. With temperature compensation, the frequency deviation of it is within +/- 0.08 ppm over -40°C to 85°C. The measured effective temperature resolution of time-domain temperature sensor is 0.45 °C/LSB and the measured error is within -6.3°C to 7.1°C at 10 Hz conversion rate. The measured current consumption of chip is about 2 mA.

Original languageEnglish
Article number6984974
Pages (from-to)225-228
Number of pages4
JournalProceedings of IEEE Sensors
Volume2014-December
Issue numberDecember
DOIs
StatePublished - 12 Dec 2014
Event13th IEEE SENSORS Conference, SENSORS 2014 - Valencia, Spain
Duration: 2 Nov 20145 Nov 2014

Keywords

  • Crystal oscillator
  • Delay cell
  • Digital control
  • Low power
  • Temperature compensation
  • Temperature sensor

Fingerprint Dive into the research topics of 'A new small-sized pierce crystal oscillator readout with novel on-chip all-digital temperature sensing and compensation'. Together they form a unique fingerprint.

Cite this