64Kbit FRAM with SPI — no-write-delay non-volatile memory
The Infineon (Cypress) FM25CL64B-DGTR is a 64Kbit Ferroelectric RAM (FRAM) memory device organized as 8K x 8 bits, accessed through an SPI bus at up to 20 MHz.
20 MHz SPI — bus-speed writes without the erase cycle
The SPI interface runs at 20 MHz, supporting both read and write operations at the same bus speed. Because FRAM writes directly to the memory array without a preceding erase cycle, the write latency is essentially the SPI transfer time — no polling for write-complete, no sector-erase wait. This matters for applications like event counters, real-time data loggers, or parameter storage where the host cannot stall for milliseconds waiting on a Flash page write.
8-DFN package — footprint for space-constrained boards
The FM25CL64B-DGTR is supplied in an 8-WDFN with exposed pad, measuring 4x4.5 mm (supplier device package 8-DFN). The exposed pad aids thermal dissipation, though for a 64Kbit FRAM the power draw is low enough that thermal management is rarely a concern.