T/R switches integrate clamping diodes to protect ultrasound imaging systems

SUNNYVALE, USA: Maxim Integrated Products has introduced the MAX4936/MAX4937 fully integrated octal high-voltage transmit/receive (T/R) switches. These switches integrate clamping diodes to isolate the low-voltage receive path from the high-voltage transmit path, thus protecting the receiver input from voltage spikes due to leakage currents flowing through the T/R switches.

Maxim's integrated solution uses > 50 percent less board space than discrete circuits while providing high bandwidth, low jitter, and low signal distortion. The MAX4936/MAX4937 are ideal for use in ultrasound imaging and industrial flaw-detection probes, in which board space is at a premium.

The MAX4936/MAX4937 feature eight individually programmable switches controlled through an SPI(TM) interface with a 12-bit shift register and transparent latch. These features simplify device operation when updating the states of the T/R switch; they ensure that all switches are off at power-on; and they reduce noise due to clock feedthrough.

The MAX4936/MAX4937 T/R are based on the conventional diode topology, but include adjustable current biasing through the serial interface. The devices are specified over the 0 degrees Celsius to +70 degrees Celsius commercial temperature range, and are packaged in a small, 5mm x 11mm, 56-pin TQFN. Prices start at $12.00 (1000-up, FOB USA).