I need help with my ultrasound project.
The transducer is Olympus V305-SU-F, they don´t provide datasheet. I want to use one pulse per work cycle with repetition of few hertz.
I have following questions:
a) How to select pulse width?
My thoughts: Here is said, that "a square wave pulse must be tuned to the frequency of the transducer", so -> 2,25 MHz -> T = 1/f -> 440 ns pulse width?
What if it will be shorter/longer. I can think only about transfered power loss.
b) What is the relationship between voltage and current? When I apply -170 V at resonant frequency with 50 ohm from Ohms law I get 3.4 amps (like is said in my another question on this side here ) Correct?
How does this work with square wave excitation? Can I lower the current with input resistor without losing the possibility of sensing the returning echo? This seems tricky for me, because I can´t get so huge current from MAX1847 and through TC6320. Any thoughts how to solve this?
My confusion come from this: All ultrasound pulsers that I have found cant handle 3.4 A. Most of them generate pulses around +- 100V. With common transducer impedance of 50 ohms the current is still to high :/
P.S. For others interested in this topic, I have found great book: Piezoelectric_Transducers_and_Applications link on PDF file