Semiconductors, FPGAs and ICs

Reading an IC part number: family, speed grade, package and temperature

Part numbers pack the key choices into the suffix. In FPGA codes like XC7A50T-2CSG324I, EP3C25Q240C8N or EP4CE40F23I7N, the family and size come first, and the suffix carries the package code and pin count, such as CSG324 or Q240, the speed grade and the temperature grade, in an order that differs between makers. Within the suffix, the letter I usually marks the industrial range and C the commercial range. Read the maker's part-numbering guide before assuming a suffix, because a one-letter difference can mean another package or a slower grade.

Packages, footprints and the datasheet check before you buy

Package decides how a part is assembled. QFP and PQFP parts have visible legs and can be soldered by hand with practice, while BGA parts such as CSBGA-324 or FBGA-484 have hidden balls and need a reflow oven or hot-air station with a stencil. The footprint on your board must match exactly, including ball pitch. Check supply voltages, I/O standards and the resource count in the datasheet, and confirm the part number against it.

Speed grades run in opposite directions between families. On the XC7 and XC6 parts in these listings a higher number such as -3 is faster, while on EP3C and EP4CE parts a lower number such as 6 is faster than 7 or 8. Temperature grades differ too: commercial parts are rated for roughly 0 to 85 degrees Celsius and industrial parts for roughly -40 to 100 degrees Celsius.

Questions about Semiconductors, FPGAs and ICs

What does the letter I in a part number mean?

Usually the industrial temperature range, about -40 to 100 degrees Celsius, against commercial for about 0 to 85. Check the datasheet's part-numbering section for that family, because letters are not universal across makers.

Can I solder a BGA FPGA by hand?

Not with an ordinary iron. Hidden balls need reflow heating, usually in an oven or with a hot-air station, plus a stencil, solder paste and a way to check the joints. QFP packages are more forgiving for hand work.

Is a faster speed grade always better?

Only if your design needs it. Faster grades allow higher clock rates, but a slower grade can meet timing in many designs. Check which direction the family counts, since for some a lower number is faster.