AS6501: 2 Channel Time to Digital Converter (TDC)

AS6501 Time-to-Digital ConverterThe AS6501 is a two-channel time-to-digital converter that is ideal for high speed measurement tasks like range finders and medical imaging.

The AS6501 features high speed LVDS interfaces for Start and Stop signals and LVDS measurement outputs. It can be used to measure the time-of-flight of optical signals to a precision of 20ps per channel, or 10ps in dual-channel high-resolution mode with up to 70 Msamples/s and unlimited measurement range.

All internal stop measures are calculated by AS6501, proportionate to the applied reference clock. It is feasible to combine the lowest pulse-to-pulse spacing of less than 5 ns, the highest data throughput rate of 70 MSPS per stop input, and the best single shot precision of 10 ps.



  • 2 stop channels with 5 ns / 20 ns pulse-to-pulse spacing.
  • Maximum 70 MSPS per LVDS output.
  • Single shot accuracy 20 ps RMS resolution per channel, 10 ps RMS with high resolution option.
  • Unlimited measuring range 0s to 16s.
  • Differential reference clock input 2 MHz to 12.5 MHz, optional with quartz.
  • LVDS Inputs and outputs, 16-stage FIFO per channel, SPI compatible 4-wire interface for configuration, optionally to be used for data readout.
  • Automatic calibrationto reference clock.
  • Supply voltage 3.3 V.
  • Power dissipation up to 450 mW, standby current 60 μA.
  • QFP48 package (7 x 7 mm², 9 × 9 mm² with leads).


  • Simple data post-processing thanks to calibrated results.
  • Event assignment thanks to reference clock and index simplifies coincidence measurements.
  • EAsy pulse width measurements.
  • High efficiency due to high sample rate.
  • Compact design thanks to small package and low number of external components.
  • Reduced cooling because of low power consumption.
AS6501 – Time-to-Digital Converter

Documentation & Downloads

Ordering Numbers

Type Part number Package RoHS compl. Shipping package
TDC-GP22 MNR 1949 QFN32 Yes Tray
TDC-GP22 MNR 1950 QFN32 Yes Tape & Reel (5k)
GP22-EVA-KIT MNR 1951 System Yes Box
GP22-DEMO-KIT MNR 1979 System Yes Box
TDC-GP21 MNR 1839 QFN32 Yes Tray
TDC-GP21 MNR 1720 QFN32 Yes Tape & Reel (3K/5K)
GP21-EVA-KIT MNR 1781 System Yes Box
TDC-GP2 MNR 1058 QFN32 Yes Tray
TDC-GP2 MNR 1480 QFN32 Yes Tape & Reel (2k)
TDC-GP1 MNR 278 TQFP44 Yes Tray
TDC-GPX MNR 975 TQFP100 Yes Tray
TDC-GPX-FG MNR 1089 TFBGA120 Yes Tray