Home > News & Analysis > MAX4805/05A: High-performance PZT and CMUT buffers increase penetration depth and sensitivity of medical ultrasound probes

Analysis

MAX4805/05A: High-performance PZT and CMUT buffers increase penetration depth and sensitivity of medical ultrasound probes

17th June 2010

Maxim Integrated

ES Admin

0 0

Maxim introduced the MAX4805 and MAX4805A, octal high-voltage-protected buffers optimized for use with piezoelectric transducers (PZT) and capacitive micromachined ultrasound transducers (CMUT), respectively. The buffers' very low voltage noise (2.1nV/rt-Hz, typ) and current noise (2.0pA/rt-Hz, typ) improve system signal-to-noise ratio (SNR) to increase penetration depth and sensitivity. The MAX4805/MAX4805A are ideal for use in ultrasound imaging and industrial flaw-detection probes, in which board space, power consumption, noise immunity, and thermal performance are critical.

The MAX4805/MAX4805A feature eight low-noise amplifiers (LNAs) in a noninverting configuration; the LNAs are controlled by an enable input, which simplifies device operation. These devices do not require dedicated Tx/Rx signals and include embedded LNA high-voltage protection. The protection is activated once the Tx voltage is greater than ±2.7V, thus making them transparent in any in-probe application.

While the MAX4805 and MAX4805A differ in terms of typical voltage gain (6dB and 9dB), input-current noise (2pA/rt-Hz and 1.7pA/rt-Hz), and input impedance (3.8kilohms and 9.1kilohms), both ICs operate from dual supply voltages of +2V and +5V. They are fully specified over the 0 degrees Celsius to +70 degrees Celsius commercial temperature range, and are available in a small, 5mm x 5mm, 32-pin TQFN package. Prices start at $23.54 (1000-up, FOB USA).