SAR convertor claims record speed and accuracy

A/D convertor achieves a new level of 16bit data capture performance, with best-in-class 15bit ENOB and 10Msample/s throughput.

Analog Devices has expanded its PulSAR family of precision 16bit SAR (successive-approximation register A/D convertors) claiming a breakthrough in data conversion that delivers an unequalled combination of speed and accuracy.

The ability to process information at higher speeds while preserving data integrity is a key requirement in today's most advanced industrial and medical systems.

For example, in medical MRI (magnetic resonance imaging) and digital X-ray systems, the speed and accuracy supported by the new PulSAR ADC enables medical procedures to be conducted more quickly and accurately, reducing the time patients must lie motionless during MRI examinations and reducing X-ray radiation exposure.

ADI's AD7626 PulSAR ADC achieves a new level of 16bit data capture performance, with best-in-class 15bit ENOB (effective number of bits) and 10Msample/s throughput, which is 2.5x faster than other SAR ADCs.

Unlike other ADCs, which operate at much lower speeds or reach higher sample rates by increasing power consumption and trading off AC and DC performance, the AD7626 PulSAR ADC has a 92dB SNR that is 8dB (1.3bit) better than any ADC, regardless of architecture.

"For high-end X-ray imaging devices, accuracy and throughput are key performance vectors that enable higher image quality and improved frame rates", said Stephane Rossignol, Electronics and ASIC Group Manager, Trixell, a leading developer of flat panel digital detectors for radiological imaging, and a joint venture company of Thales Electron Devices, Philips Medical Systems and Siemens Healthcare.

"Trixell, a long time partner of Analog Devices, chose the AD7626 PulSAR ADC, which meets the speed, precision, power, package-sise and price requirements of our end-system designs".

"From factory automation systems that boost productivity to sensitive medical imaging equipment that quickly and noninvasively scan patients, virtually all manufacturers want to push the speed barrier while holding a firm line on data accuracy", said Leo McHugh, Product Line Director, Precision Signal Processing, Analog Devices.

"The AD7626 takes a dramatic jump forward in terms of sampling rates, while delivering linearity performance that rivals convertors with much lower throughputs".

For applications that do not require full 10Msample/s datarates, the AD7626 can be easily multiplexed.

Some medical imaging devices, for example, could use the AD7626 in a two-channel configuration where each channel operates at 5Msample/s.

This would allow the system designer to lower materials costs by reducing data convertor component count by 50% - while still maintaining speeds that are 25% faster than existing solutions.

"Data conversion technology determines the quality of the user experience in applications as diverse as ultrasound imaging to digital TV, mobile phones and other consumer goods", said Susie Inouye, Research Director at Databeans , a leading semiconductor research firm.

"Because there are such a variety of end uses, however, there is no single specification that defines a good data convertor".

"OEMs today need semiconductor design partners to solve tough signal processing challenges, and ADI engineers are among the best at bridging the analogue and digital worlds through delivering the right convertor for the problem".

Housed in a compact 5 x 5mm QFN (quad flat no-lead) package that is 70% smaller than competing offerings, the AD7626 consumes just 130mW of power, which even at its highest sample rate is 15% lower than other ADCs in its class.

The AD7626 also uses a self-clocked low-voltage differential serial (LVDS) bus that provides a very-low-noise interface and reduces the number of external components required to address board-level noise concerns.

The company has also released introduced the AD7625 16bit PulSAR ADC, which operates at 6Msample/s and expands the PulSAR family to 15 devices with speed options ranging from 1 to 10Msample/s and dynamic range of 16 to 18bit.

Analog Devices' extensive PulSAR family is based on an ADC architecture that provides the added advantage of zero data latency, which is critical in precision data acquisition systems.

The AD7626 and AD7625 PulSAR ADCs are available now in production quantities.

The AD7626 comes in a 32-lead QFN (quad flat no-lead) package and is priced at US $34 per unit in 1000-unit quantities.

The AD7625 comes in a 32-lead QFN package and is priced at US $32 per unit in 1000-unit quantities.

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