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TDC-GP2: The General Purpose Time To Digital Converter

acam TDC-GP21 Time to Digital Converter

TDC with Special Features for Ultrasonic Flow Meters and Ultrasonic Heat Meters

The TDC-GP2 is a acam general-purpose Time to Digital Converter (TDC). Higher resolution and smaller package size make it ideal for cost-sensitive industrial applications. With special function blocks like a fire pulse generator, stop enable, temperature measurement, and clock control, it is perfectly suited for flowmeter and heat-meter applications.

TDC-GP2 is not recommended for new design.

General Circuit Features

Measurement range 1

  • 2 channels with typ. 50 ps rms resolution
  • 65 ps Bin size
  • Measurement range 3.5 ns to 1.8 µs
  • 15 ns pulse-pair resolution with 4-fold multihit capability
  • 4 events can be measured arbitrarily against each other
  • Windowing for precise stop enable

Measurement range 2

  • 1 channel with typ. 50 ps rms resolution
  • 65 ps Bin size
  • Measurement range 500 ns to 4 ms
  • 2 x CLKHS pulse-pair resolution with 3-fold multihit capability
  • Each of the 3 events can be assigned to an adjust-able measuring window with 10ns resolution

Special Features

  • Fire pulse generator for up to 15 pulses with programmable phase
  • 4 temperature measurement ports for 16 Bit temperature measurement
  • Clock calibration unit
  • Typical current consumption 5 µA

General Features

  • Trigger to rising and/or falling edge
  • I/O voltage 1.8 V to 5.5 V
  • Core voltage 1.8 V to 3.6 V
  • 1 MHz continuous data rate max.
  • Temperature range 40°C to 125°C
  • 4 wire SPI interface
  • QFN 32 package

Block Diagram

Package Outline


  • Laser Distance Meters
  • Ultrasonic Flowmeter
  • Ultrasonic Density meter
  • Ultrasonic Thickness Meter
  • Magnetostrictive Positioning
  • Drift Chambers
  • Frequency & Phaseshift