This paper presents a new architecture for time-to-digital conversion enabling a time resolution of 17ps over a range of 50ns with a conversion rate of 20MS/s. The proposed architecture, implemented in a 65nm FPGA system, consists of a pipelined interpolating time-to-digital converter (TDC). The TDC comprises a coarse time discriminator and a fine delay line, capable of sustained operation at a clock frequency of 300MHz. A Turbo version of the circuit implements a pipelined interpolating TDC with suppressed dead time to reach a conversion rate of 300MS/s at the expense of a systematic asymmetry that requires fast error correction. The TDCs proposed in this paper can be compensated for process, voltage, and temperature (PVT) variations using a conventional charge pump based feedback or a digital calibration technique. Results demonstrate the suitability of the approach for a variety of applications involving high-precision ultra-fast time discrimination, such as optical lifetime sensing, time-of-flight cameras, high throughput comlinks, RADARs, etc.
Abstract1 -A novel imaging technique is proposed for fully digital detection of phase and intensity of light. A fully integrated camera implementing the new technique was fabricated in a 0.35μm CMOS technology. When coupled to a modulated light source, the camera can be used to accurately and rapidly reconstruct a 3D scene by evaluating the time-offlight of the light reflected by a target. In passive mode, it allows building differential phase maps of reflection patterns for image enhancement purposes. Tests show the suitability of the technique and confirm phase accuracy predictions.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.