RF Engines emulates TI's Graychip direct downconverters in an FPGA

March 13, 2012 // By Nick Flaherty
UK-based signal processing company RF Engines has developed specific IP to emulate the functions of TI's GrayChip direct down converters to provide an upgrade path to designs originally built upon them, particularly for radar and defence applications.

Using specifically designed sub-modules, a channelizer design can be built on an FPGA platform for higher performance, greater customization options and a lower price than the increasingly hard to obtain mature devices.

As a number of Texas Instruments Graychip (GC) range of devices transition to "Not Recommended" for new designs and "Obsolete" status, customers are asking for the capabilities of devices such as the Graychip GC1012B Wideband DDC says the company.

"Manufacturers are coming to the stage of designing the next generation of their products only to find that a key component they had used, such as the TI Graychip GC1012A has become obsolete, and the GC1012B wideband DDC is 'not recommended' for new designs, hard to obtain and expensive at around $240 each," said Dr Alex Kuhrt, RFEL's CEO. "At the request of customers, we have created emulations of the DDC functionality, using our DSP technology that runs on a low-cost FPGA part and delivers improved performance and lower system costs, saving 75% on the effective unit cost."

The designs are not pin-for-pin replacements, but, as companies design new PCB layouts for their next generation of products, it is a straight-forward process to take advantage of the increased performance, lower power consumption and extended features on offer, such as support for fractional decimation factors up to 16,384 as standard - a capability not offered by many of the latest DDC chips.

The first design available delivers the equivalent functionality of a GC1012B device, but can process higher sample rates and provides one additional output as standard, with more available on request.

"One of the many advantages of our IP approach is that we can easily migrate our implementation from one generation of FPGA to the next and to different manufacturers, while ensuring functional compatibility, and that the most optimal design techniques available are used," said Dr Kuhrt. "This is important for products developed for EW and counter-intelligence, for example,