Analog Devices' AD8333 is a dual-channel I/Q demodulator and phase-shifter for CW Doppler ultrasound. The monolithic Doppler phase-shifter IC achieves a dynamic range of 161 dB/Hz, which is equal to or exceeds the dynamic range of existing multichip solutions, while using less than 25% of the board space per channel and delivering a per-channel bill of materials savings of up to 75%.
The AD8333 provides the same coherent summing and phase alignment of multiple input channels as competing products while consuming just 190 mW/channel and significantly reducing circuit board area.
CW Doppler ultrasound systems require ABF because the large dynamic range cannot be processed digitally. The dual-channel AD8333 significantly alters this approach by replacing it with a programmable phase-shifting technique with an I/Q demodulator for each input channel, eliminating the need for multiple analog delay lines and cross-point switches. The reduction in board space and low power allow for an increase in continuous wave functionality compared to the delay line approach.
The AD8333 is designed with 22.5 ° phase steps, allowing for accurate time alignment of multiple channels in continuous wave beam-forming applications. The amplifier offers parallel l4-bit digital control of phase states, and provides accurate channel matching through a common LO interface.
The AD8333 monolithic Doppler phase-shifter is sampling and will be in full production in August. The device is offered in a 5 mm × 5 mm LFCSP (lead-frame chip scale package) and is priced at $8.95 each in 1,000-unit quantities.
Analog Devices Inc. • (800) 262-5643 • www.analog.com