Cypress Semiconductor Corp FM31256-GTR

The FM31256-GTR combines 32K x 8 nonvolatile ferroelectric RAM with a clock/calendar, programmable low-voltage reset, watchdog timer, early power-fail comparator, two battery-backed event counters and a programmable 64-bit serial number. The F-RAM and companion functions use separate logical I2C addresses, allowing timekeeping access without disturbing the current memory address.

The customer catalog lists 14-SOIC (0.154 inch, 3.90 mm width). The package registry normalizes this to 14-SOIC, with the expected image path below. Infineon identifies package drawing 51-85067 / PG-DSO-14; verify pin 1, lead pitch, body width and land pattern against that drawing.

Layout checks

• Compare the 14-lead 150-mil outline and pad geometry with drawing 51-85067.
• Confirm polarity, pin numbering and the backup-supply routing.
• Do not infer footprint equivalence from the SOIC name alone.

The registered local package JPG is missing and must be supplied and visually verified before publication.

The manufacturer's 14-pin SOIC pin-definition table identifies these signal groups:

Follow the manufacturer's rules for unused PFI, CNT and backup pins; verify exact pin numbers on the package pinout before layout release.

Application conditions and guaranteed electrical limits must be taken from the complete manufacturer data sheet.

FM31256-G is the same documented density and 14-pin SOIC family with standard tube ordering media, but its exact supply status and lot traceability still require confirmation. FM3164-G has lower 64-Kbit memory density and requires software/storage requalification. FM31256-G1 and FM31278-G are separate catalog entries, not approved substitutes on model similarity alone. The product database contains these codes, but none is linked here because their target pages are unpublished.

Check pinout, bus addressing, memory map, RTC configuration, reset thresholds, watchdog behavior, package drawing, environmental qualification and procurement lifecycle before substitution.

Cypress Semiconductor introduced the FM31256-GTR; Infineon now hosts its controlled documentation and labels the exact order code discontinued. Infineon's product page identifies a 14-pin PG-DSO-14 / SOIC-14 package and tape-and-reel packing, 2,500 units per reel. Any remaining distributor inventory needs date-code and authenticity review.

Because the order code is discontinued, verify chain of custody, date code, package marking, moisture exposure and solderability for any remaining stock. Confirm the complete OPN, not merely the FM31256 family name, against procurement records.

Use the latest Infineon-controlled data sheet and package outline for final electrical and mechanical approval. This draft does not establish current supply, a substitute qualification or verified live pricing. Resolve those issues and add the registered package JPG before publication.