Ultrasonic Flow Converters
TDC-GP22 ULTRASONIC FLOW CONVERTERS
Ultrasonic Flow Converter with Integrated Analog Frontend
The TDC-GP22 is a two-channel TDC that has extra analog components to make it easier to use in ultrasonic flow meter applications, such as an extended fire-pulse generator, zero-cross detection, and analog switches.
TDC-GP22 works well for high dynamic applications such as ultrasonic water meters since it has an additional first-hit detection feature. The various units’ excellent power management reduces the running current to a few µA at a 2Hz measurement rate.
For even higher integration and lower current consumption, please see the TDC-GP30.
Ultrasonic Flow Converters (UFC)
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
General
- 4-wire SPI interface
- 1 MHz continuous data rate max.
- I/O voltage 2.5 V to 3.6 V
- Core voltage 2.5 V to 3.6 V
- Temperature range – 40 °C to +125 °C
- QFN 32 package
Measurement Mode 1
- 2 channels with typ. 90 ps resolution
- 1-channel double resolution with typ. 45 ps
- Range 3.5 ns (0 ns) to 2.5 µs
- 20 ns pulse-pair resolution, 4-fold multiunit
- Up to 1 million measurements per second in measure mode 1
Measurement Mode 2
- 1 channel with typ. 90 ps resolution
- Double resolution mode with 45 ps, Quad resolution mode with 22 ps resolution
- Measurement range 500 ns to 4 ms
- 3-fold multiunit capability with automatic processing of all 3 data
Special Functions
- Fire pulse generator, up to 127 pulses
- Trigger to rising and/or falling edge
- Precise stop enable by windowing
- Low-power 32 kHz oscillator (500 nA)
- Clock calibration unit
- 7×32 Bit EEPROM
Analog Input Circuit
- Chopper-stabilized low-offset comparator, programmable, ±35 mV
- First-wave detection: offset set zero automatically after first wave, hit selection relative to first wave
- First-wave pulse-width measurement for signal monitoring and bubble detection
- Integrated analog switches for input selection
- External circuit is reduced to 2 resistors and 2 capacitors
Temperature Measurement Unit
- Chopper-stabilized low-offset comparator, programmable, ±35 mV
- First-wave detection: offset set zero automatically after first wave, hit selection relative to first wave
- First-wave pulse-width measurement for signal monitoring and bubble detection
- Integrated analog switches for input selection
- External circuit is reduced to 2 resistors and 2 capacitors
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 |
CPU |
– |
Memory |
|
GPIO |
– |
Ambient Temperature Range [°C] |
-40°C to +125°C |
Package |
QFN32 |
Resolution
OTHER SPECS
| Max data rate: | up to ½ million samples per second |
| Power supply voltage: | 2.5 V to 3.6 V |
| Operating temp: | -40°C to 125°C |
| Quiescent current: | < 0.1µA |
| INL: | < 0.1 LSB |
| DNL: | < 0.8 LSB |
GP22 DC PARAMETERS
TEMPERATURE MEASURING UNIT
MEASURING UNIT
