A circuit for an ultrasonic channel has a first and a second terminal between which extend a
resistive and diode signal paths including a pair of diodes with opposing polarities, for
example in anti-parallel. Switching circuitry is coupled with the resistive and diode signal
paths and is switchable between first and second states. In the first state, the first and the
second terminals are coupled with one another via the resistive signal path. In the second
state, the first and the second terminals are coupled with one another via the diode signal …