Patent ID: 8265569

Claim:
An apparatus comprising: a transmitter coupled to an ultrasonic transducer at a first node, the transmitter being configured to generate an ultrasound signal during a transmit period; a transmit/receive switch having an input coupled to the first node, wherein the transmit/receive switch further comprises: one or more field effect transistors (FETs) coupled between the first node and a second node, wherein the one or more FETs are configured to be turned on during a receive period to couple the first node and the second node such that an echo signal is passed from the first node to the second node during the receive period, and to be turned off during the transmit period to substantially block the ultrasound signal from the second node; and a clamp circuit coupled to the second node, wherein the clamp circuit is configured to protect the second node from excess voltages; and a receiver having an input coupled to the second node to receive the echo signal, wherein the echo signal comprises echoes of the ultrasound signal.