SLDA058 March   2021 TUSS4470

 

  1.   Trademarks
  2. 1Review of Ultrasonic Sensing Range Performance Factors
    1. 1.1 Physical Parameters
    2. 1.2 Transducer Characteristics
    3. 1.3 AFE Device Configuration
  3. 2Methods Overview
    1. 2.1 Introduction
    2. 2.2 Hardware Configuration
      1. 2.2.1 Transducers
      2. 2.2.2 Experimental Setup: Air-Coupled Level Sensing
      3. 2.2.3 Experimental Setup: Water-Coupled Level Sensing
      4. 2.2.4 TUSS4470 EVM Hardware Configuration
      5. 2.2.5 TDC1000-C2000EVM Hardware Configuration
    3. 2.3 Firmware Configuration
      1. 2.3.1 TUSS4470 Power Configuration
      2. 2.3.2 TUSS4470 220 kHz Configuration
      3. 2.3.3 TDC1000 220kHz Configuration
      4. 2.3.4 TDC1000 220kHz Configuration
      5. 2.3.5 TDC1000 1 MHz
  4. 3Short Range Air-Coupled Test Results
    1. 3.1 TUSS4470
    2. 3.2 TDC1000
  5. 4Mid-Range Air-Coupled Test Results
    1. 4.1 TUSS4470
      1. 4.1.1 Concept
      2. 4.1.2 TUSS4470 35 V Results
    2. 4.2 TDC1000
  6. 5Short Range Water-Coupled Test Results
    1. 5.1 TUSS4470
    2. 5.2 TDC1000
  7. 6Resistive Damping Device Comparison
    1. 6.1 TUSS4470
    2. 6.2 TDC1000
  8. 7Summary
  9. 8References
  10.   A Appendix A
    1.     A.1 TUSS4470: Filter Capacitor Selection
    2.     A.2 TUSS4470: Shematic
  11.   B Appendix B
    1.     B.1 TDC1000 Misc.
    2.     B.2 TDC1000-C2000EVM Schematic

4.2 TDC1000

A series of measurements was taken to experimentally determine the upper distance boundary. CH1: START, CH2: COMPIN, CH3: STOP.

GUID-20210310-CA0I-C6MK-WJMS-SXSW3PJCW81X-low.png Figure 4-3 Mid-Range Air-Coupled Results: TDC1000

The standard ToF measurement mode was used in anticipation of a longer ToF, however, it was not necessary. Since the maximum range is limited by echo attenuation, a similar result would be seen in short ToF mode. In the standard mode, noise is seen on the COMPIN pin during the auto-zero period, this should not be mistaken for the received echo. The end of the reliable range was found to be about 10cm. Just beyond 10cm, the signal is too weak to be reliably trigger a stop pulse with the 35 mV threshold.

In Figure 4-4, the signal is too weak to trigger a stop.

GUID-20210310-CA0I-TND5-CS10-KLCQZ2B7BXRJ-low.png Figure 4-4 Mid-Range Air-Coupled Results: TDC1000