Integrated Analog Front End (AFE) Contains Eight Ultrasound Receive Channels in a Single IC
The AD9271 delivers an unprecedented level of integration for cart and portable ultrasound designers. Each of the eight channels features a low noise amplifier (LNA), 8 × 6 differential crosspoint switch for continuous wave (CW) doppler, variable gain amplifier (VGA), antialiasing filter (AAF), and 12-bit analog-to-digital converter (ADC). The AD9271 operates on a 1.8 V supply, consuming only 150 mW/channel at 50 MSPS. With eight channels in a 16 mm × 16 mm, 100-lead TQFP, the AD9271 allows ultrasound system designers to increase their channel count and image quality without increasing the size or power consumption of the equipment.
By integrating high performance elements into a single IC, superior image quality is enabled on portable and cart-based ultrasound systems used in emergency rooms, doctors' offices, and clinics. Each channel of the AD9271 features a variable gain range of 30 dB, typical input referred noise of 1.2 nV/√Hz @ 5 MHz, input dynamic range of 157 dB/√Hz, a programmable third-order Butterworth antialiasing filter, a 12-bit ADC with an SNR of 70 dB, and SFDR (spurious-free dynamic range) of 80 dB. It is possible to power down individual channels to extend battery life during display mode only, or to power down the data conversion path when using the LNA in CW mode.