AN-000158
Document Number: AN-000158
Page 5 of 22
Revision: 1.2
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OVERVIEW
THEORY OF OPERATION
The CH101 and ICU-10201 are ultrasonic transceiver rangefinders that use a piezoelectric micromachined ultrasonic transducer
(PMUT) to send out short pulses of soundwaves into the air. Upon hitting an object, these waves reflect back towards the PMUT,
causing it to vibrate and generate an electrical signal. The time needed for the soundwaves to travel from and back to the PMUT,
known as the Time-of-Flight (ToF), is measured by the built-in application-specific integrated circuit (ASIC). Using the speed of sound
(343 m/s at room temperature), the system can determine the distance to the object.
Unlike other types of ToF rangefinders, such as infrared (IR) sensors, the CH101 and ICU-10201 sensors are not affected by the color
or transparency of objects and works in all lighting conditions. It also uses significantly less power than comparable IR sensors and
the
sensor’s
Field-of-View (FoV) can be customized by using different acoustic housings.
PACKAGE DIMENSIONS
Figure 1. Package dimensions of the CH101.
