A Linear 126-dB Dynamic Range Light-to-Frequency Converter with Dark Current Suppression Upto 125 °c for Blood Oxygen Concentration Detection

Fang Tang, Zhou Shu, Kai Ye, Xichuan Zhou, Shengdong Hu, Zhi Lin, Amine Bermak

Research output: Contribution to journalArticle

5 Citations (Scopus)


This paper presents a high linear dynamic range light-to-frequency converter (LFC) with integrated photodiodes (PDs). The high dynamic range with linear response is achieved by two techniques. At first, the NWell/PSubstrate PD is regulated to almost zero voltage drop, in order to minimize the bias-dependent leakage current under a low light irradiance. Secondly, a replica amplifier is implemented to monitor the offset voltage of the regulator against process-voltage-temperature variation. As the result, the systematic and layout-dependent input offset voltage of the regulator can be reduced. The proposed LFC chip is fabricated using 0.35- μm 2-poly-3-metal nonepitaxy CMOS technology with a die size of 1.02 × 0.83 mm2. According to the measurement results, the proposed LFC is much less sensitive to temperature variation and it exhibits more than six orders of magnitude linear response under the light irradiance as low as 0.5 nW/cm2 with a temperature range from -25 °C to 125 °C.

Original languageEnglish
Article number7551144
Pages (from-to)3983-3988
Number of pages6
JournalIEEE Transactions on Electron Devices
Issue number10
Publication statusPublished - 1 Oct 2016



  • Biomedical signal detector
  • high dynamic range
  • light-to-frequency converter (LFC)
  • photodetector

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Electrical and Electronic Engineering

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