A 32-kHz Real-Time Clock Oscillator with On-Chip PVT Variation Compensation Circuit for Ultra-Low Power MCUs

• TSUBAKI Keishi

  Kobe University

• HIROSE Tetsuya

  Kobe University

• KUROKI Nobutaka

  Kobe University

• NUMA Masahiro

  Kobe University

Abstract

This paper proposes an ultra-low power fully on-chip CMOS relaxation oscillator (ROSC) for a real-time clock application. The proposed ROSC employs a compensation circuit of a comparator's non-idealities caused by offset voltage and delay time. The ROSC can generate a stable, and 32-kHz oscillation clock frequency without increasing power dissipation by using a low reference voltage and employing a novel compensation architecture for comparators. Measurement results in a 0.18-μm CMOS process demonstrated that the circuit can generate a stable clock frequency of 32.55 kHz with low power dissipation of 472 nW at 1.8-V power supply. Measured line regulation and temperature coefficient were 1.1%/V and 120 ppm/°C, respectively.

Journal

• IEICE Transactions on Electronics

  IEICE Transactions on Electronics E98.C (5), 446-453, 2015

  The Institute of Electronics, Information and Communication Engineers

Keywords

• ROSC
• RTC
• oscillator
• comparator
• PVT variation
• low-power

Details

• CRID: 1390001204377482880
• NII Article ID: 130005067737
• DOI: 10.1587/transele.e98.c.446
• ISSN: 17451353
• ISSN: 09168524
• Web Site: https://www.jstage.jst.go.jp/article/transele/E98.C/5/E98.C_446/_pdf
• Text Lang: en
• Data Source:
  • JaLC
  • Crossref
  • CiNii Articles
  • KAKEN
• Abstract License Flag: Disallowed