Design and assessment of a 6 ps-resolution time-to-digital converter with 5 MGy gamma-dose tolerance for LIDAR application

Ying Cao, Wouter De Cock, Michiel Steyaert, Paul Leroux

    Research outputpeer-review


    Time-to-Digital Converters (TDCs) are key building blocks in time-based mixed-signal systems, used for the digitization of analog signals in time domain. A short survey on state-of-the-art TDCs is given. A novel multi-stage noise-shaping (MASH) delta-sigma (δ,σ) TDC structure is proposed for applications in continuous-time pulsed time-of-flight (TOF) rangefinders for nuclear reactor remote sensing, which requires both high resolution and multi MGy gamma-dose radiation tolerance. The converter, implemented in 0.13 μm, achieves a time resolution of 5.6 ps and an ENOB of 11 bits, when the oversampling ratio (OSR) is 250. The TDC core consumes only 1.7 mW and occupies an area of 0.11 μm 2. Owing to the usage of circuit level radiation hardened-by-design techniques, such as passive RC oscillators and constant-g m biasing, the TDC exhibits enhanced radiation tolerance. At a low dose rate of 1.2 kGy/h, the frequency of the counting clock in the TDC remains constant up to at least 160 kGy. Even after a total dose of 3.4 MGy at a high dose rate of 30 kGy/h, the TDC still achieves a time resolution of 10.5 ps with an OSR of 250.

    Original languageEnglish
    Article number6200900
    Pages (from-to)1382-1389
    Number of pages8
    JournalIEEE transactions on nuclear Science
    Issue number4 PART 2
    StatePublished - 2012

    ASJC Scopus subject areas

    • Nuclear and High Energy Physics
    • Nuclear Energy and Engineering
    • Electrical and Electronic Engineering

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