Texas Instruments has introduced 8-channel and 16-channel analog front ends (AFEs) especially for handheld ultrasound systems. Claiming 40 percent less power than TI's AFE58xx family and 70 percent smaller than competitive analog front ends for ultrasound systems, the two AFEs are likely to bring ultrasound capability in a size that fits a doctor's pocket. It is envisaged that such handheld ultrasound systems could be used as a medical diagnosis tool in remote regions and by medical technicians in 'first response' situations " just as a stethoscope is used now.
Employing 16 variable gain amplifiers (VGAs) and eight 12bit, 65MS/s analog to digital converters (ADCs) to provide 39mW/channel at 32.5 MS/s, the AFE5851 offers a high channel count. Two VGAs share the ADC and each VGA differential output is sampled at alternate clock cycles to optimise power efficiency. Meanwhile, the AFE5801 offers 50mW/channel at 30MS/s and 58mW/channel at 50MS/s and integrates eight VGAs and eight 12bit, 65 MS/s high-speed ADCs with LVDS data outputs.
Both the AFE5851 and AFE5801 suit an architecture whereby a transformer or an off-chip low-noise amplifier is located on the probe. This is done to maximise power efficiency.
The devices come in a 9mm x 9mm, 64-QFN package, and samples and evaluation modules are now available.