The 4GHz Time-to-Digital Converter

A high performance timing unit.

The Kore 4GHz Time-to-Digital Converter

Our most advanced timing electronics yet, the Kore 4GHz time-to-digital converter (TDC) is a compact, bench-top timing unit designed to record a fast stream of event times relative to a single start event. It performs this task with a timing resolution of 0.25 ns with minimal dead time, high data rates and the ability to repeat the experiment at very high repetition rates. These features make the unit ideal for use in Time-of-Flight (TOF) mass spectrometry applications. In such an application, the unit issues or receives a cycle start signal at pre-set intervals and waits to receive timing pulses from an ion detector. The pulse times are recorded, buffered and streamed to the PC via a standard USB 2.0 serial interface. Here the standard driver software may process them to spectra ‘live’, or stream them to the hard disk for more flexible processing options.


We also offer to bundle the TDC with a data acquisition computer running GRAMS/AI™ – a general spectroscopy program from Thermo Scientific for which Kore has written time-of-flight mass spectrometry ‘extensions’. With this bundle, a user can add the ability to acquire and manipulate time-of-flight mass spectrometry data to their instrumentation, without needing to write their own data acquisition software.

  • 0.25ns timing resolution
  • Maximum burst rate of 2 GHz
  • Very high sustained count rate
  • Internal or external ‘start’ triggers
  • Fast multiple-experiment control implemented in hardware
  • Independent mains-powered case (optional 1U rack mount case) with easy interfacing to a PC via a standard USB 2.0 interface.
  • Efficient, interrupt-driven drivers allow the PC to continue working (e.g. simultaneous data processing of data stream)
  • Software configurable input levels and input edge polarity for maximum flexibility
  • Rich array of driver functions and utilities specifically aimed at TOF-MS
  • Backed by Kore’s extensive knowledge of TOF-MS design (for those who have this application in mind)
  • Optional GRAMS/AI™ package for data collection, plotting, data-management etc. customised by Kore for use with the TDC
Timing resolution0.25ns
Number of hits per cycleUnlimited
Maximum burst count rate2 GHz
Full speed front end FIFO depth8192 frames of 4ns
Maximum sustained count rate>17,000,000 counts/s (Theoretical)
>4,000,000 counts/s (Measured)
Maximum time stamp value0xFFFEFF ~4.2 millisec
Triggering modesFixed frequency free-running OR External Start trigger
Max cycle repetition rate≥ 1MHz (hardware)
200 kHz (current software limit)
Min cycle repetition rate (free running)≤20 Hz (hardware)
500 Hz (current software limit)
Min cycle repetition rate (External start trigger)Unlimited
Number of cycles per experiment (on board counter)1 to 4x109
Cycle counter reset time<1µs
Dead time between cycles36ns at cycle start and 4ns at end
Timing precision<470ps (1 hour measurement of peak at 500µs) estimated as 280ps internal trigger & 380 ps external trigger 2 )
Start/Stop input range-5V to +5V
Start/Stop input threshold range-2.5V to +2.5V (positive or negative timing edges selectable in software)
Start/Stop input termination (jumper selectable)50Ohm to ground (Normal) OR 50Ohm to -2V (ECL)
PC interfaceUSB 2.0
Power requirement (typical for board)+5V 730mA and -5.2V 65mA
Bench-top case dimensions280 x 300 x 70 mm
Bench-top power requirement230/115 VAC 50/60Hz 7watt
Software requirementWindows XP or later

Our new 4GHz TDC can be purchased together with a data acquisition system running GRAMS/AI™ with Kore TOF Mass Spectral ‘extensions’. Such a package would be of use to researchers who are building TOF-MS apparatus or have existing equipment and would like to purchase a complete TOF data acquisition / data plotting system.


GRAMS/AI™ from Thermo Scientific is a general spectroscopy software suite. Kore has been using the GRAMS™ platform successfully for many years in its instrumentation, and has written what we term ‘mass spectral extensions’ specifically for the case of time-of- flight spectrometry.


Key Features of GRAMS/AI™ and Kore Mass Spectral Extensions:

  • Kore extensions to GRAMS/AI™ simplify data collection using the Kore TDC. All collection parameters are set up via standard Windows-style dialogue boxes
  • Time data can be converted automatically to mass data with Kore’s conversion program. This has the advantage of producing mass spectra with values at equally spaced mass intervals (user selectable) that preserve the exact number of counts in the original data
  • The equally spaced mass intervals allow the full range of GRAMS/AI™ processing routines to be used subsequently
  • GRAMS/AI™ features a full set of data manipulation tools
  • User-specific tools can be created by the user and placed as icons on the toolbar
  • The new AI version introduces many improvements including an enhanced user interface and a collection of updated processing routines based on Microsoft™ ActiveX technology
  • The ExcelExchange module allows seamless transfer of data between GRAMS/AI™ spectral data files and Microsoft™ Excel™ worksheets. Data can be easily transferred in both directions: from a GRAMS™ data file into an Excel™ worksheet and from a worksheet to a data file.
  • Spectral DB provides a data management tool for organising spectra and chromatograms into a simple, searchable database
  • Spectral ID provides a comprehensive search tool. Spectral pattern matching or “library searching” is one of the most efficient, effective methods for qualitative identification of compounds using Mass Spectrometry
  • Handles all types of spectral and chromatographic data from virtually any analytical instrument
  • The GRAMS™ Suite also supports a number of general-purpose data formats such as SPC, ASCII, JCAMP, and AnDI/NetCDF
  • For storing data, the GRAMS™ Suite utilizes the universal SPC file format enabling scientists to share data with colleagues easily.
Analogue mode

A very fast digitiser, or analogue-to-digital converter (ADC), records the shape of the pulse waveform into memory. All the pulses resulting from a single spectrometer start event are recorded in a single trace; so in principle a complete mass spectrum can be recorded from one spectrometer cycle. However to achieve acceptable precision, it is often necessary to add a number of traces together to give an average.



The arrival time of each ion pulse is recorded as a simple number, or time-stamp, by a time-to-digital converter (TDC). The implicit assumption is that each pulse represents a single ion; all information about the shape of individual pulses is discarded. To create a mass spectrum, many spectrometer cycles are performed, typically a few thousand, and the time-stamps built into an arrival-time histogram.


The best strategy depends on the experiment, in particular on the number of ions expected in a single cycle and on any constraints to the cycle repetition rate e.g. a laser that won’t pulse faster than 10Hz.

Pricing and ordering

Kore Technology is a centre of excellence in time-of-flight mass spectrometer technology and has a very strong R&D capability in terms of its personnel, all of whom have been heavily involved in a variety of analytical instrumentation development programmes.


If you have any questions please feel free to contact us via our online form or telephone us for more information, we offer a wide range of products and services to suit your requirements.


If you wish to purchase our products, please contact Kore sales at, or call +44 (0)1353 653030.

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