SLAA907D September   2019  – December 2021 PGA450-Q1 , PGA460 , PGA460-Q1 , TDC1000 , TDC1000-Q1 , TDC1011 , TDC1011-Q1 , TUSS4440 , TUSS4470

 

  1.   Trademarks
  2. 1What is Ultrasonic Time-of-Flight Sensing?
    1. 1.1 Principles of Ultrasound
    2. 1.2 Why Use Ultrasonic Sensing?
    3. 1.3 How Does Ultrasound Compare to Other Sensing Technologies?
    4. 1.4 Typical Ultrasonic-Sensing Applications
  3. 2Ultrasonic System Considerations
    1. 2.1 Introduction to the Ultrasonic System
    2. 2.2 The Ultrasonic Echo and Signal Processing
    3. 2.3 Transducer Types
    4. 2.4 Transducer Topologies
    5. 2.5 Transducer Frequencies
    6. 2.6 Transducer Drive (Transformer Drive & Direct Drive) and Current Limit
    7. 2.7 Pulse Count
    8. 2.8 Minimum Detection Range
  4. 3What Factors Influence Ultrasonic Sensing?
    1. 3.1 Transmission Medium
    2. 3.2 Acoustic Impedance
    3. 3.3 Radar Cross Section
    4. 3.4 Ambient Conditions (Temperature, Humidity, Debris)
    5. 3.5 Device Selection
  5. 4Additional Resources
  6. 5Revision History

2.3 Transducer Types

Transducers come in two types: closed-top and open-top. Although open-top transducers are lower cost, and require a smaller driving voltage to achieve maximum Sound Pressure Level (SPL), they are unreliable in harsh environments. Exposure to rain, dust, and other contaminants will damage the sensor.

GUID-27AF912A-36FB-4F12-878E-664A3FC16EA6-low.pngFigure 2-6 Closed-Top and Open-Top Transducers (From PGA460EVM)