The AD9674 is designed for low cost, low power, small size, andease of use for medical ultrasound. It contains eight channels of aVGA with an LNA, a CW harmonic rejection I/Q demodulatorwith programmable phase rotation, an AAF, an ADC, a digitalHPF, and RF decimation by 2.

Each channel features a maximum gain of up to 52 dB, a fullydifferential signal path, and an active input preamplifier termination.The channel is optimized for high dynamic performance andlow power in applications where a small package size is critical.

The LNA has a single-ended to differential gain that is selectablethrough the serial port interface (SPI). Assuming a 15 MHz noisebandwidth (NBW) and a 21.6 dB LNA gain, the LNA input SNR is94 dB. In CW Doppler mode, each LNA output drives an I/Qdemodulator that has independently programmable phaserotation with 16 phase settings.

Power-down of individual channels is supported to increase batterylife for portable applications. Standby mode allows quick power-upfor power cycling. In CW Doppler operation, the VGA, AAF, andADC are powered down. The ADC contains several featuresdesigned to maximize flexibility and minimize system cost, such asa programmable clock, data alignment, and programmable digitaltest pattern generation. The digital test patterns include built infixed patterns, built in pseudorandom patterns, and customuser defined test patterns entered via the SPI.

Applications

• Medical imaging/ultrasound
• Nondestructive Testing (NDT)

This product has been released to the market. The data sheet contains all final specifications and operating conditions. For new designs, ADI recommends utilization of these products.