ADI ultrasound receiver is first to feature on chip digital I/Q demodulation

The AD9670 integrates a low noise amplifier, variable gain amplifier, anti aliasing filter and 14bit a/d converter with the industry's highest sample rate (125MS/s) and best signal to noise ratio performance (75dB) for enhanced ultrasound image quality. Because of the embedded demodulation and decimation feature, ADI says the device is the first to be able to condition eight channels of data from rf to a baseband frequency, reducing the processing load on the system fpga by at least 50% compared to other receivers. "By introducing the first octal ultrasound receiver with digital demodulation and decimation filtering, we are able to minimise the data I/O and throughput rates and place less stress on the system processor," said Pat O Doherty, vice president of healthcare, Analog Devices. "At the same time, by extending the anti aliasing filter frequency range and maintaining a high a/d converter sample rate, we are continuing to help medical and industrial ultrasound equipment manufacturers meet the trend toward higher frequency probes and superior image quality." The new low power receiver is targeted at mid to high end portable and cart based ultrasound systems. It is designed to provide a continuous wave processing path with an analogue I/Q demodulator that has harmonic rejection to the 13th order, enabling designers to reduce the number of filter components to lower system cost, reduce design complexity and improve signal sensitivity.