To verify the functionality of the chip, an ultrasonic range finder was implemented. A range finder is used to measure distance by calculating the time in which a sound wave takes to travel a certain distance. To test this, a function generator was synced with an oscilloscope while also connected to a Murata MA40S4S 40kHz ultrasonic transducer. The output of the analog front end was then measured on a different oscilloscope channel.

On the rising edge of the square wave, the transducer was activated and the distance of the output signal could be measured in time. The time difference between the rising edge of the input and the measured output can be used to calculate the distance. In Figures 1, the input sound wave reaches the receiver in approximately 2ms. Assuming the speed of sound is 343m/s, the approximate distance is 68cm. At a 4ms time of flight the distance was measured to be approximately 136cm which matches closely with the theoretically calculated distance. The included video goes into more detail on the measurement procedure and results for the range finder.