12-16-2013 07:22 AM
I am considering the use of a series 7 FPGA as a logic core for a harsh environment application requiring -55 to 125 degree C operation. While Xilinx provides multiple FPGA device options guaranteed through this temperature range, I do not see any appropriately rated proms for this temp range. What programming prom devices are recommended for this type of application?
12-16-2013 02:29 PM
A quick DigiKey search finds very little in the way of flash or EPROM or EEPROM that goes down to -55 degrees C. The only one I could find cost about $500 and had an "extreme" temperature range of -55 to +210 for applications like "down hole energy drilling" (Texas Instruments). It's also SPI (which should theoretically work) and only runs in single data rate at up to 12 MHz. So if you decide to use it, I hope you have plenty of start-up time.
12-16-2013 04:29 PM
Two suggestions as a followup:
1. Do you have a microprocessor in your system, by which you can configure the FPGA in slave serial mode?
2. Consider adding a 'heater' to your board design to warm the flash memory (and perhaps the rest of the board) to an ambient temperature within the operating range of the components in your design. You can configure the heater to turn on when at power-up and be disabled or controlled by the FPGA after configuration.
-- Bob Elkind
12-16-2013 04:38 PM
12-16-2013 04:58 PM
... and heat control cannot be guaranteed for my applications.
I would like to greatly simplify my existing solutions by integrating the logical elements of the design (including the processors), but unfortunately the lack of a reasonable prom solution will greatly impact the trade study.
"Simplify" is an inappropriate term to apply to a design requiring operation at -55 degrees C. Operating at the fringes or limits of your technology is never 'simple'.
It is wonderful that the FPGA supports full temp ranges, but we are missing a critical element of the solution.
Your problem is only starting with the configuration memory. The config memory is not your only problem. It is more accurate to say that the FPGA is the least of your temperature range 'problem', and the rest of the board is the rest of your 'problem'.
-- Bob Elkind
12-16-2013 05:23 PM
12-17-2013 07:18 AM
XILINX Power Estimator(XPE) tool /Xilinx Power Analyzer (XPA) helps to customer to estimate theJunction temperature.