TDC-GP21 Ultrasonic Flow Converter
Time-to-digital converter with integrated analog front-end

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

Benefits
– High precision
– Low power
– Few additional external component needed

Product parameters
Analog Frontend: Yes
First Wave Detection: –
Amplitude Measurement-
Number of Hits3
Resolution [ps]22
Operating Supply Range: 2.5 to 3.6
Interface: SPI
CPU: –
Firmware: –
Memory: –
GPIO: –
Ambient Temperature Range [°C]: -40 to +125
Package: QFN32

General Description
TDC-GP21 is a 2-channel TDC with additional analog elements like extended fire-pulse generator, zero-cross detection and analog switches for simplifying the use in ultrasonic flow meter applications. An optimized power managements of the various units brings down the operating current to a few µA at 2Hz measuring rate.

Type : analog, power, digital, temperature, measuring, down
Bus : 1 analog input
Applications : for electromagnetic flow meters
Other characteristics : 2-channel