256-channel, 16-bit digital X-ray analog front end delivers industry’s best combination of noise, power and image quality

November 28, 2012 // By Paul Buckley
Analog Devices, Inc., has introduced a highly integrated digital X-ray analog front end (AFE) which claims to offer the industry’s lowest noise performance in multiple power-mode options, and the highest image quality.

The 256-channel ADAS1256 digital X-ray AFE is the industry’s first single-chip solution to integrate the complete charge-to-digital conversion signal chain by incorporating low-noise programmable-charge amplifiers, correlated double-sampling circuitry and 16-bit A/D converters. With a noise figure of an equivalent charge of 560 electrons at a 2-picocoulomb full-scale range, the ADAS1256 enables high resolution digital X-ray images while reducing patient exposure to X-ray dose. The ADAS1256 has multiple functional power modes ranging from 1-mW/channel to 3-mW/channel, allowing manufacturers to address a wide range of digital X-ray modalities including portable radiology and mammography as well as high speed fluoroscopy and cardiac imaging.
 
“Thanks to the ultra-low-noise profile and dynamic range of the ADAS1256, digital X-ray technology will continue to deliver better diagnostic image quality and reduce radiation dosage applied to patients compared to existing digital X-ray systems,” said Pat O’Doherty, vice president, healthcare group, Analog Devices. “By achieving this level of performance while adhering to a strict power budget, the ADAS1256 digital X-ray AFE provides medical equipment designers with a single device that serves the growing high-performance requirements of the portable digital X-ray market.”

The ADAS1256 is a 256-channel, simultaneous sampling, high dynamic range, low power analog front end that is a complete charge-to-digital conversion signal chain. It incorporates 256 low noise integrators, low pass filters, and correlated double samplers that are multiplexed into a high speed, 16-bit, A/D converter. All converted channel results are output on a single LVDS (low-voltage differential signalling) self-clocked serial interface. The ADAS1256 can be programmed using an SPI-compatible daisy-chain serial interface. It is delivered on a high density system-on-flex (SOF) package and can be directly mounted on a digital X-ray panel.

The 16-bit ADAS1256 features 256 channels and is priced at $256 in 1K-piece quantities.