The AD9671 is designed for low cost, low power, small size, and
ease of use for medical ultrasound applications. It contains eight
channels of a VGA with an LNA, a CW harmonic rejection I/Q
demodulator with programmable phase rotation, an AAF, an
ADC, and a digital demodulator and decimator for data
processing and bandwidth reduction.
Each channel features a maximum gain of up to 52 dB, a fully
differential signal path, and an active input preamplifier termination.
The channel is optimized for high dynamic performance and
low power in applications where a small package size is critical.
The LNA has a single-ended to differential gain that is selectable
through the serial port interface (SPI). Assuming a 15 MHz noise
bandwidth (NBW) and a 21.6 dB LNA gain, the LNA input SNR
is 94 dB. In CW Doppler mode, each LNA output drives an I/Q
demodulator that has independently programmable phase
rotation with 16 phase settings.
Power-down of individual channels is supported to increase
battery life for portable applications. Standby mode allows quick
power-up for power cycling. In CW Doppler operation, the
VGA, AAF, and ADC are powered down. The ADC contains
several features designed to maximize flexibility and minimize
system cost, such as a programmable clock, data alignment, and
programmable digital test pattern generation. The digital test
patterns include built-in fixed patterns, built-in pseudorandom
patterns, and custom user defined test patterns entered via the SPI.
Applications
- Medical imaging/ultrasound
- Nondestructive testing (NDT)