High speed data converter simplifies FPGA interconnect design

Analog Devices has launched a dual-channel, 14bit, 250MSPS, analog-to-digital converter that connects seamlessly to high-speed FPGAs and enables precise multi-channel converter synchronisation.

The AD9250 features a JEDEC JESD204B serial output data interface standard and is first-to-market with full JESD204B Subclass 1 deterministic latency at 250MSPS. This accommodates the precise synchronisation of multiple data-conversion channels through a serial interface.

Communications infrastructure, imaging equipment, industrial instrumentation, defence electronics and other multi-channel, data-hungry systems are demanding wider resolutions and higher sampling rates from the data conversion stage. Physical layout constraints of the parallel interface and bit-rate limitations of the serial LVDS (low-voltage differential signalling) approach are beginning to present technical barriers for designers. The JESD204B serial interface reduces the number of high-speed differential output data paths required from as many as 28 to just two per IC. Its Subclass 1 deterministic latency function is repeatable from power-up cycle to power-up cycle and across link re-synchronisation events. Areas where this function is important are in diversity radio systems and instrumentation, multi-mode digital receiver applications such as TD-SCDMA, WCDMA, LTE (especially the 2R2T >8R8T evolution), radar/defence electronics, medical imaging systems, cable infrastructure and general-purpose software radios.

The serial interface implementation provides up to 5Gbps over a 1 or 2 lane-capable link. Two serial lanes are used to support the full 250MSPS, dual A/D converter data rate, or a single lane can be used to support reduced sampling rates.

High-performance FPGA suppliers such as Xilinx have incorporated on-chip JESD204B SerDes (serialiser/deserialiser) ports into their latest generation products. This end-to-end seamless connectivity for the analog signal chain results in simplified PCB layout, rapid prototyping capability, and faster time-to-market.

“Xilinx is fully-committed to supporting the JEDEC JESD204B standard and is striving to accelerate adoption of the serialised interconnect technology for data converters. We are doing this by providing high quality, flexible, scalable and programmable IP to interface with high speed data converters like the AD9250,” said Sunil Kar, senior director, Wireless Business Group at Xilinx. “Xilinx currently provides JEDEC JESD204B IP for Subclass 0, 1 and 2 functionality, with line rates up to 10.3GBPS and lane widths ranging from x1 to x8 on our devices. This combination of technology advancements improves system modularisation, lowers cost and complexity and will enhance the capabilities and capacities of next generation wireless and wired networks.”

“This signals a new, tightly integrated approach to designing the analog signal chain in FPGA-based systems,” said Kevin Kattmann, product line director, High-speed A/D Converters at Analog Devices. “The AD9250 delivers unmatched wideband signal processing performance while its simplified interface breaks design barriers for next-generation FPGA-based applications in software-defined radio and medical ultrasound. For many system designers, the I/O challenge in implementing the high-performance analog signal chain now has an elegant solution.”

The AD9250-250EBZ (250 MSPS), AD9250-170EBZ (170 MSPS), and AD6673-250EBZ DUT boards, and companion HSC-ADC-EVALDZ high-speed data capture card, comprise a signal performance-optimised complete evaluation system for the AD9250. The captured data can be analysed using a laptop computer and ADI’s free VisualAnalog software. For compatibility with FPGA development platforms, the CVT-ADC-FMC-INTPZB FMC interposer connector for the DUT boards is available.
A 170MSPS pin-compatible version (AD9250-170) is available, as well as the AD6673, an 11bit, 250MSPS, pin-compatible version.

This article originally appeared in EE Times Europe.

0 comments on “High speed data converter simplifies FPGA interconnect design

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.