TIME TO DIGITAL CONVERTERS

TDC-GP22: General Purpose Time to Digital Converter (TDC)

TDC-GP22 Ultrasonic Flow Meter ChipThe TDC-GP22 time to digital converter is the perfect solution for consumer and industrial applications requiring low cost, high resolution, and exceptionally low current consumption. Applications like low cost range finders, magnetostrictive sensors, and automatic test equipment are just a sampling of the applications that can take advantage of this technology.

With single shot resolution of 22ps and a 4 ms measurement range, the TDC-GP22 has the resolution and timing range for many applications that require precise measurement, while still being a low cost part.

In Measurement Mode 1, the chip measures up to 4 events (hits) per channel with a minimum of zero nano seconds time difference between the channels. In Measurement Mode 2, the TDC-GP22 chip can measure up to 3 events (hits).

Like all the ScioSense TDCs, the TDC-GP22 offers low current consumption, which makes it perfect for battery-powered applications.

Advantages

  • Ultra Low Current Consumption with only few µA.
  • Up to 8 STOP Channels
  • Automatic Calibration of the Measured Value
  • External Reference Clock in the Range of 1 to 40 MHz.

Products

TDC-GP22 Main Features

General Features

  • 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

Circuit Features

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 multihit
  • 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 multihit capability with automatic processing of all 3 data

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

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

FUNCTIONAL BLOCK DIAGRAM

Block Diagram of the TDC-GP22 Ultrasonic Flow Converter

Additional Information

TDC-GP22 Specification

Resolution
typ. 90 ps, 45 ps in double resolution mode, 22 ps in quad resolution mode (only Measure Mode 2)

 

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

TEMPRATURE MEASURING UNIT

TIME MEASURING UNIT

TDC-GP22 PRODUCT FACTS

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

TDC-GP22 APPLICATIONS

  • Gasmeters
  • Watermeters
  • Density and Level Sensors

Documentation & Downloads

Ordering Numbers

Type Part number Package RoHS compl. Shipping package
TDC-GP22:
TDC-GP22 MNR 1949 QFN32 Yes Tray
TDC-GP22 MNR 1950 QFN32 Yes Tape & Reel (5k)
GP22-EVA-KIT MNR 1951 System Yes Box
GP22-DEMO-KIT MNR 1979 System Yes Box
TDC-GP21:
TDC-GP21 MNR 1839 QFN32 Yes Tray
TDC-GP21 MNR 1720 QFN32 Yes Tape & Reel (3K/5K)
GP21-EVA-KIT MNR 1781 System Yes Box
TDC-GP2:
TDC-GP2 MNR 1058 QFN32 Yes Tray
TDC-GP2 MNR 1480 QFN32 Yes Tape & Reel (2k)
TDC-GP1:
TDC-GP1 MNR 278 TQFP44 Yes Tray
TDC-GPX:
TDC-GPX MNR 975 TQFP100 Yes Tray
TDC-GPX-FG MNR 1089 TFBGA120 Yes Tray