AS6501 Time-to-Digital Converter

2-Channel TDC with LVDSA Inputs/Outputs


  • 2 stop channels with 5 ns / 20 ns pulse-to-pulse spacing
  • Maximum 70 MSPS per LVDS output
  • Event assignment thanks to reference clock & index simplifies coincidence measurements
  • Single shot accuracy 20 ps RMS resolution per channel, 10 ps RMS with high resolution option
  • Easy pulse width measurements
  • Unlimited measuring range 0s to 16s
  • High efficiency thanks high sample rate
  • Differential reference clock input 2 MHz to 12.5 MHz, optional with quartz
  • Compact design thanks to small package and low number of external components
  • LVDS inputs and outputs, 16-stage FIFO per channel, SPI compatible 4-wire interface for configuration, optionally to be used for data readout
  • Reduced cooling thanks to low power consumption
  • Automatic calibration to 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

Product parameters

Channels 2
Inputs LVDS / CMOS
Resolution [ps] 10
Pulse-Pair Resolution [ns] 5
Measurement Rate [MSPS] 70
Multi-Hit Capability Unlimited
Operating Supply Range [V] 2.4 to 3.6
Interface LVDS / SPI
Ambient Temperature Range [°C] -40 to 125
Package QFP48

General Description

The AS6501 is a high performance 2-channel time-to-digital converter (TDC) frontend device based and derived from TDCGPX2. Highest measurement performance and highest data throughput is achieved with LVDS stop inputs and LVDS serial outputs for each channel. Current saving operation is also possible with CMOS inputs and SPI readout.

High configuration flexibility and unlimited measurement range cover many applications. They range from portable handheld laser range equipment to ambitious time-of-flight measurements of highest performance, as e.g. done in medical imaging applications. AS6501 operates without any locked loop
technologies. AS6501 calculates all stop measurements inside,
proportional to the applied reference clock. Combinations of
best single shot accuracy of 10 ps with lowest pulse-to-pulse
spacing <5 ns and maximum data throughput rate of 70 MSPS
per stop input are possible.

This product suits for the following applications:

  • Laser rangefinders
  • Automated test equipment
  • Medical imaging
  • ToF spectroscopy

Technical Documents

Type Description Language
Datasheet 2-Channel Time-to-Digital Converter English

Environmental Documents

Type Description Language
RoHS Certificate RoHS Certificate AS6501 English

Other Information

Type Description Language
Block Diagram AS6501 Blockdiagram English
Factsheet Knowing precisely where to go English

Related Products

Ownership of this product has moved to Sciosense

Please be informed that this product is now owned by Sciosense B.V., a joint venture of ams AG and Wise Road Capital, effective January 13th, 2020.

ScioSense Environmental Sensors