TDC Overview

ACAM TIME TO DIGITAL CONVERTERS

Time-to-digital converters (TDCs) are devices used to measure time intervals in the range of 1 nanosecond down to the picosecond range. The first time-to-digital converters were developed for scientific and research purposes. They were considered a combination of a time-to-analog (TAC) and analog-to-digital (ADC) converter.

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The ACAM Time to Digital Converters are used in applications that were previously analog based. They offer much higher resolution and lower current consumption than their analog counterparts. This low current consumption makes these time to digital converters ideal for wireless applications.

Advantages

  • Ultra Low Current Consumption with only few µA.
  • Up to 8 STOP Channels
  • Automatic Calibration of the Measured Value
  • External Reference Clock in the Range of 1 to 40 MHz.


INTEGRATED DIGITAL TIME TO DIGITAL CONVERTERS

Thanks to modern CMOS-technology it is possible to integrate fully digital time to digital converters into a single chip. The high precision of the time measurement - down to 14 ps - in combination with the large dynamic range (up to 30 Bit), the high stability over temperature and supply voltage and the possibility of a low cost production thanks to the CMOS technology make them the first choice for industrial applications.



CUSTOMER-SPECIFIC INTEGRATED TDCs

The use of pure digital circuit design makes it easy to build on the performance features of the standard products and improve specific technical data. Accordingly, acam develops optimized TDC's which are tailored to the specific measuring requirements of the customer.

  • Additional measuring modes
  • Additional mathematical operations for on-chip data processing (e.g. high performance 32 floating point units with focus on low power consumption)
  • Memory (FIFO, EEPROM...)
  • Various interfaces
  • µC cores

The wealth of experience acam has gathered assures the ability to integrate all necessary funtions on a single circuit and so to provide a system-on-chip solution.


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    IMPLEMENTATION EXAMPLES

    TDC-S1 is a TDC with 25ps standard deviation for use in the ATV (Automatic Transport Vehicle) that will supply the ISS (International Space Station). The high resolution is all the more impressive as this TDC is realized on a radiation hard process.

    DFA1 Integrated circuit for detection of the rotation of a propeller meter with extremely low current consumption (<2uA) - contacless, non-magnetic und feedbackless.


    CUSTOMER-SPECIFIC SYSTEMS

    On the base of the ATMD-System we also develop complete solutions and additional modules to fit your application.

    Take as an example the AM-HM1 histogramming module, that was developed for RoentDek. This is a standalone PC-based 4-channel TDC with 32MB Histogram memory for fast readout of Delay-Line-Detectors developed by RoentDek. For more information, please contact RoentDek.

    Another example is the Time-of-Flight Module offered by GPTA (Gesellschaft für physikalisch-technische Anwendungen). The key features of this module are virtually dead time free operation, 5 ns multihit dead time in 1 channel mode, (60±5) ps maximum resolution, an input for multicard coincidence measurements. For more information, please email sales@gpta.de

    TIME-OF-FLIGHT MODULE
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    TDC-SI MODULE
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    AM-HMI-HISTOGRAMMING MODULE
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    DescriptionVersionSizeDownload
    Datasheet TDC-GP22 Eval System:
    Preliminary datasheet for TDC-GP22 evaluation system
    V0.25.3MBDB_GP22-EVA_en.pdf
    Datasheet TDC-GP22:
    Datasheet for TDC-GP22 Time-to-Digital Converter
    V0.94MB
    Datasheet TDC-GP21 Eval System:
    Preliminary datasheet for TDC-GP21 evaluation system
    V0.25.3MB
    Datasheet TDC-GP21:
    Datasheet for TDC-GP21 Time-to-Digital Converter
    V1.64MB
    Datasheet TDC-GPX:
    ATMD evaluation system for TDC-GPX (DISCONTINUED)

    1.3MB
    Datasheet TDC-GP1:
    2-channel TDC, 250 ps/125 ps

    1MB
    Datasheet TDC-GP2:
    2-channel TDC 65 ps
    V2.02.6MB
    Datasheet TDC-GPX2 Eval System:
    Preliminary datasheet for TDC-GP22 evaluation system
    V0.22948kB
    Datasheet TDC-GPX2:
    4-Channel Time-to-Digital Converter
    V0.21979kB
    Datasheet TDC-GPX:
    8-channel TDC 81 ps, 2-channel TDC 41 ps/27 ps/10 ps
    V0.2800kB
    DescriptionVersionSizeDownload
    Application Note 034:
    Laser Range Finder with the TDC-GP22
    V1.3837kBAN034_en.pdf
    Application Note 027:
    TDC-GP2 to TDC-GP21 Migration and Compatibility Guideline
    V0.1400kBAN027_en.pdf
    Application Note 024:
    Metrological Investigations of TDC-GP2 Temperature Measurement Unit
    V1.01.2MBAN024_en.pdf
    Application Note 016:
    TDC-GPX Reduced Decoupling
     73kBAN016_en.pdf
    Application Note 013:
    TDC-GPX - PLL Regulation Circuit
    V3.0100kBAN013_en.pdf
    DescriptionVersionSizeDownload
    Software TDC-GPX2:
    Evaluation software package for GPX2 (incl. doc, cfg, drv)
    V1.0.5206MBCD-GPX2-EVA.zip
    Software TDC-GP22:
    STM32 µC Sample code of Application Note 034
     42kBGP22_main_AN034.c
    Software TDC-GP22:
    Software package for GP22-EVA-KIT
    V1.9111MBCD-GP22-EVA-XP-WIN7.zip
    Software TDC-GP21
    Software package for GP21-EVA-KIT
    V3.9104MBCD-GP21-EVA-XP-WIN7.zip
    Software TDC-GPX:
    Evaluation software for ATMD-GPX
    V4.018MBATMD-GPX.zip
    Software TDC-GPX:
    Visual-C++ sample code for ATMD-GPX
     214kBATMD-GPX-C-samples.zip
    Software ATMD-PCI:
    Driver files for ATMD-PCI interface card
     2kBAcamAtmdPci.zip
    Software PICOPROG V3.0 (V2.0):
    Driver Installer Stand-Alone
    R115MBPicoProg_v2_Driver_Installer_Stand-Alone.zip
    Software National Instruments:
    NI VISA instrument drivers
    V3.012MBni-visa.zip
    Software National Instruments:
    NI VISA runtime engine for Windows 7
    V4.6253MBvisa462runtime.exe
    Software National Instruments:
    NI VISA runtime engine for Windows Vista
    V4.141MBvisa410full.exe
    Software National Instruments:
    NI VISA runtime engine for Windows XP
    V3.214MBvisa320runtime.exe
    Software National Instruments:
    NI VISA runtime engine for Windows 98
    V2.68MBvisa260runtime.exe
    DescriptionVersionSizeDownload
    PCN/PDN TDC-GP1
    Pd-free package
    V167kBPCN0104.pdf
    PCN/PDN TDC-F1
    Pb-free package
    V149kBPCN0204.pdf
    PCN/PDN TDC-F1
    Discontinuation of production
    V168kBPDN0711-01.pdf
    PCN/PDN ATMD-GP1
    Discontinuation of production
    V134kBPDN1009-01.pdf
    TDC MEASURING METHOD

    INTEGRATED DIGITAL TIME-TO-DIGITAL CONVERTERS

    Digital delay time TDCs are integrated circuits for high precision time interval measurement and do this without any analog components. They became real thanks to the innovations in semiconductor technology made over the years. They use the propagation delays of simple logical gates (i.e. inverters) for fine quantization of time intervals. Due to the enormous achievements in signal speed, especially in the CMOS sector, it has become possible to implement

    such TDCs in standard CMOS technology with a resolution in the picosecond range. Nowadays we can integrate system solutions into a single chip that are efficient, power saving, space saving and none the less low price.

    Digital TDCs can be split into two groups:

    • Absolute delay time TDCs
    • Relative delay time TDCs


    ABSOLUTE DELAY TIME TDC

    This type of TDC uses the absolute propagation time of signals through simple logical elements for fine quantisation of time intervals. (see figure below)

    In other words, it determines how many inverter cycles the measured time interval consists of. The figure shows the principle of operation. Clever circuit set-ups, redundant elements and special layout methods on the chip enable the exact reconstruction of the number of basic time intervals. The resolution strictly depends upon the basic delay time in the chip. Resolutions in the range of 14 -100 ps can be achieved by a simple set-up of the measuring core and the use of a state-of-the art CMOS process. The propagation delay itself depends on temperature and supply voltage. Therefore the measured value must be calibrated. This is done by measuring one and two periods of a reference oscillator. Ideally this measurement and the following calculation is done by the TDC itself.

    Absolute delay time TDCs have the following advantage:

    • The delay time of the inverter can be precisely adjusted and stabilized by using a phase controlled loop (PLL). It is independent from supply voltage and temperature.
    • Good pulse-pair resolution
    • Multi-hit capability
    TypePart numberPackageRoHS compl.Shipping package
    TDC-GP22:
    TDC-GP22MNR 1949QFN32YesTray
    TDC-GP22MNR 1950QFN32YesTape & Reel (5k)
    GP22-EVA-KITMNR 1951SystemYesBox
    GP22-DEMO-KITMNR 1979SystemYesBox
    TDC-GP21:
    TDC-GP21MNR 1839QFN32YesTray
    TDC-GP21MNR 1720QFN32YesTape & Reel (3K/5K)
    GP21-EVA-KITMNR 1781SystemYesBox
    TDC-GP2:
    TDC-GP2MNR 1058QFN32YesTray
    TDC-GP2MNR 1480QFN32YesTape & Reel (2k)
    TDC-GP1:
    TDC-GP1MNR 278TQFP44YesTray
    TDC-GPX:
    TDC-GPXMNR 975TQFP100YesTray
    TDC-GPX-FGMNR 1089TFBGA120YesTray

    ADDITIONAL INFORMATION