By Topic

An FPGA-Integrated Time-to-Digital Converter Based on Two-Stage Pulse Shrinking

Sign In

Cookies must be enabled to login.After enabling cookies , please use refresh or reload or ctrl+f5 on the browser for the login options.

Formats Non-Member Member
$31 $13
Learn how you can qualify for the best price for this item!
Become an IEEE Member or Subscribe to
IEEE Xplore for exclusive pricing!
close button

puzzle piece

IEEE membership options for an individual and IEEE Xplore subscriptions for an organization offer the most affordable access to essential journal articles, conference papers, standards, eBooks, and eLearning courses.

Learn more about:

IEEE membership

IEEE Xplore subscriptions

2 Author(s)
Szplet, R. ; Mil. Univ. of Technol., Warsaw, Poland ; Klepacki, K.

We present the design and test results of a new time-to-digital converter based on the cyclic pulse shrinking method and implemented in a field-programmable gate array (FPGA) device. The pulse shrinking is realized in a loop containing two complementary delay lines. The first line shrinks, and the second line stretches the duration time of a circulating pulse; hence, the length ratio of the lines determines the pulse-shrinking capability of the converter. This resolution control mechanism is different from the bias adjustment typically used in complementary metal-oxide-semiconductor (CMOS) application-specific integrated circuit (ASIC) pulse-shrinking elements. Two forms of representation of a measured time interval (the pulse width and the time interval between two pulses) are utilized in the described converter to improve the efficiency of resolution control. To diminish the jitter of the edges of a circulating pulse and, consequently, to increase the precision of the converter, a two-stage conversion is introduced. The first stage, having a low resolution, rapidly shortens the measured pulse, thus limiting the number of cycles, whereas the second stage provides a final high resolution within a narrow time interval range. The optimal resolution of the first conversion stage is theoretically derived. Mostly, the same logical resources of the FPGA device are utilized in both conversion stages; thus, the overall area overhead of the converter is reduced. The converter has a resolution of 42 ps and a measurement uncertainty of below 56 ps within the measurement range of 11.5 ns. The converter has been implemented in a general-purpose reprogrammable device Spartan-3 (Xilinx).

Published in:

Instrumentation and Measurement, IEEE Transactions on  (Volume:59 ,  Issue: 6 )