USonic Xducr
Converts electrical pulses into 20 kHz–100 MHz acoustic waves (and back), enabling distance measurement, flow metering, NDT inspection, medical imaging, and high-power cleaning/welding processes.
In an ultrasonic ranging system, a driver excites a transducer to send an acoustic burst. A receiver detects the returning echo. The round-trip time and speed of sound in the medium determine the distance. Some systems reuse one transducer; others have separate transmit and receive elements. Target shape, acoustic impedance, temperature and humidity affect the measurement. A ranging transducer is not automatically suitable for imaging, cleaning or medical treatment.
In plain terms
Like a flashlight that emits sound instead of light — the transducer chirps a brief, high-frequency 'click' you can't hear, then listens for the echo bouncing back from anything in its path.
Why designers use it
- Measuring distance from the time taken by an acoustic echo to return.
- Detecting suitable objects without relying on their visible color.
- Sensing in an appropriate acoustic medium with a transducer and driver designed for that application.
Best for
- Distance sensors
- Medical imaging
- NDT
Key specifications
- Operating limits: Check the exact manufacturer's datasheet (A family name does not establish voltage, current, temperature or timing limits.)
- Pin assignment: Match the complete part and package code (A similar name or function does not guarantee the same wiring.)
- Mechanical fit: Use the exact package drawing (Check pad layout, dimensions and viewing direction before building.)
When not to use it
- Across a vacuum gap: an acoustic wave needs a material medium.
- When the required range, target angle or material gives an insufficient echo for the selected sensor.
- When temperature, humidity, noise or attenuation exceed the design's tested conditions.
Common mistakes
- Assuming a headline maximum range applies to every target and environment.
- Using a drive voltage, waveform or frequency not rated for the transducer.
- Ignoring the target angle or a soft material that absorbs rather than returns the echo.
- Applying a speed-of-sound assumption for the wrong medium or temperature.
Where you will find it
- TI's ultrasonic-sensing guide describes measuring a target's range from its returning acoustic echo.
- An angled or sound-absorbing target can return a weaker echo than a hard surface facing the sensor. Test the actual target and environment rather than borrowing a medical-probe or cleaning-transducer specification.
A short history
Ultrasonic ranging turns a transmitted sound pulse and its returning echo into a distance measurement. A system may use one transducer for both jobs or separate transmitter and receiver elements. Ring-down creates a near-field limitation, while frequency, target properties and the environment affect useful range.