Other Parts Discussed in Thread: PGA460,
Hi
In TI's ultrasonic sensing app note SNIA020, p7 is this statement
a highly symmetrical transmit and receive signal path is needed. The electrical impedance of the path can be controlled using an impedance matching solution, based on the principal of electroacoustic reciprocity
On p8 it continues A remarkable benefit of using the sensor interfacing circuit designed by Texas Instruments is that a lower cost sensor can be used to achieve high accuracy at zero-flow condition, without the need for tedious calibration to adjust the offset error over the temperature range
Can someone outline how few R. C somehow make the whole system better?
I think the final effect TI achieves is that the two Tx/Rx sensors (which do indeed function "reciprocally" in that the role of transmit & receive is taken alternately
by each sensor) now have essentially the same characteristics for Tx/Rx in either direction.
I'm unsure how the RC help exactly. At a guess, the accoustic path is somehow considered as one with the electrical path, thus permitting a "circuit analysis".
Also: Will this work for gas measurement applications?
Regards
Stephen
