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Ultrasonic Flow Converter with Integrated Analog Frontend

TDC-GP22 is an integrated ultrasonic flow converter front end.

It is a 100% pin and functionally compatible upgrade to TDC-GP21. It has additional functionality compared to the TDC-GP21 - the first hit detection and the patented signal strength monitoring by pulse width measurement. This makes it the first complete and easy to use front-end chip for ultrasonic water meters and heat meters.

The TDC-GP22 has analog elements like the fire-pulse generator, zero-crossing detection and analog switches that simplify the design of ultrasonic flow meters. The first-hit detection makes TDC-GP22 suitable for high dynamic range ultrasonic water meters. The optimized power management of the various subsystems allows the operating current to be only a few µA at 2 Hz measurement rate.

The TDC-GP22 is a good front-end solution for designing compact, low-cost ultrasonic flow meters and heat meters.

For even higher integration and lower current consumption, please see the TDC-GP30.

Key Features

  • 2-channel TDC with 22ps resolution
  • Analog frontend for ultrasonic flow meters
  • Chopper-stabilized low-offset comparator for zero crossing detection
  • Precise windowing for hit selection
  • Temperature measuring unit for PT1000 sensors
  • QFN32 Package

Key Benefits

  • High Precision
  • Low Power
  • Few Additional External Component Needed

TDC-GP22 Product Facts

Analog Frontend Yes
First Wave Detection Yes
Amplitude Measurement
Number of Hits 3
Resolution [ps] 22
Operating Supply Range 2.5 to 3.6
Interface SPI
Ambient Temperature Range [°C] -40°C to +125°C
Package QFN32