Comparison of TDC Circuit Design Method to Constant Delay Time

  • Choi, Jin-Ho
  • Received : 2010.06.29
  • Accepted : 2010.07.26
  • Published : 2010.08.31


This paper describes the design method of Time-to-Digital Converter(TDC) to obtain the constant delay time and good reliability. The reliability property is described with delay elements. In TDC the time signal is converted to digital value which is based on delay elements for the time interpolation. To obtain the constant delay time, the first and the last delay elements have different structure compared to the middle delay elements. In the first and the last delay elements, the driving ability could be controlled for the different delay time. The delay element can be designed by analog and digital devices. The delay time of the element using analog devices is not sensitive to process parameters than that of the element using digital devices. And the TDC circuit by the elements using analog devices shows better reliability than that by the elements using digital devices also.


time-to-digital converter;analog delay element;digital delay element;load balancing;process variation


  1. Sidney Soclof, "Applications of Analog Integrated Circuits," Prentice-Hall, 1985.
  2. Alan B. Grebene, "Bipolar and MOS Analog Integrated Circuit Design," Wiley-Interscience, 1983.
  3. Jian Song, Qi An and Shubin Liu, "A high-resolution Time-to-Digital Converter Implemented in field programmable gate array," IEEE Trans. Instrum. Meas., vol. 53, no. 1, Feb. 2006.
  4. Poki Chen and Shen-Iuan Liu, "A Cyclic Time-to-Digital Converter With Deep Sub-nanosecond Resolution," IEEE 1999 Custom Integrated Circuits Conference pp. 605-608, 1999.
  5. R. cicalese, A. Alosio, P. Branchini, R. Giordano, V. Izzo and S. Loffredo, "Implementation of High-Resolution Time-to-Digital Converters on two different FPGA devices," WSPC-Proceedings, pp. 1-5, 2007.
  6. Jin-Ho Choi, "Delay Time Reliability of Analog and Digital Delay Elements for Time-to_Digital Converter," International Journal of KIMICS, vol. 7, no. 1, Feb. 2010.
  7. Poki Chen, Shen-Iuan Liu and Jingshown Wu, "Highly Accurate Cyclic CMOS Time-to-Digital Converter with Extremely Low Power Consumption," Electronics Letter, vol. 33, no.10, pp.858-860, 1997
  8. Hong Jun Park, "CMOS Analog Integrated Circuit Design," Sigma Press, 1999.