Doppler Phase Shifter Outfits Portable Ultrasound Equipment

The AD8339, a quad I/Q demodulator and phase shifter, replaces delay lines in ultrasound equipment to reduce component count and power consumption. The device reduces board space by replacing the large crosspoint-switch matrices and analog delay lines typically used in phased-array beam forming. It consumes 73 mW per channel, said to be 30% less than comparable devices. Other features include a dynamic range of 158 dB/Hz, 22.5° phase steps, SPI, single synchronized common local-oscillator (LO) input for all channels, a quadrature phase error of ±0.5°, I&Q amplitude imbalance of 0.25 dB, LO frequency range of 100 MHz, and a basic RF input frequency range of 25 MHz. Available in a 40-lead LFCSP, price is $11.95 each/1,000. ANALOG DEVICES INC., Wilmington, MA. (800) 262-5643.