Hokkaido University Research Profiles

Japanese
Information and Communication

Low-power A/D Converters for Sensing

Use of time to digital converter for A/D converter and its low power consumption

Single-Slope A/D converters, which involve the simplest configuration, are used in various forms (image sensors, etc.). However, one drawback is their slow conversion speed. With this technique high speed and low power consumption can be achieved simultaneously.

Content of research

Single-Slope A/D converters convert analog values to time and then digitize them. By using the Time to Digital Converter (TDC), the conversion time can be greatly reduced. However, power consumption increases significantly. Intermittent operation of the TDC is effective to reduce the power consumption of the TDC part by a factor of several times ten, enabling both high speed and low power consumption. The features of this method are as follows:
Realization of low-power, high-speed, small-area A/D converters
・Synchronization and consistency of two measurements with high precision and coarse accuracy are guaranteed in principle
・The A/D conversion characteristics are continuous and easy to correct.

Potential for social implementation

  • ・A/D converter for image sensors
  • ・A/D converter for harsh environments and sensing arrays
  • ・High-precision time measurement instrument

Appealing points to industry and local governments

At the Laboratory for Integrated NanoSystems , we study integrated technologies from those used in devices to circuits to signal processing. We specifically focus on high-speed, low-power, and intuitive I/F of systems for image sensing and global and local adaptive image processing.

Intellectual property related to this research

PCT/JP2013/053734  「積分型AD変換装置およびCMOSイメージセンサ」
 (日本:特許第6195161号 米国:特許第9,571,113号 欧州:13749907.5 韓国:10-2014-7025397)
2022/5/27Released