CY7C291A-35WMB

The Cypress CY7C291A-35WMB is a high-speed 2K x 8 reprogrammable CMOS PROM from the CY7C291A/292A/293A family, supplied in a windowed ceramic dual-in-line package (CDIP) that allows full erasure and reprogramming via ultraviolet light. This device organizes 16,384 bits of non-volatile storage as 2,048 words by 8 bits and delivers access times down to 35 nanoseconds, combining fast state-machine decode logic with the inherently low power consumption of CMOS technology. Its parallel interface and fully static operation eliminate the need for external clocks, while the transparent lid on the hermetically sealed ceramic package provides both physical ruggedness and the optical path required for UV erasing cycles during development and field updates.

Typical system roles for this PROM include embedded firmware storage, microprogram sequencing, and configuration bitstream storage in military avionics, mission-critical industrial controllers, and aerospace guidance platforms. The CDIP construction, often associated with MIL-STD-883 screening or similar high-reliability flows, suits environments demanding extended temperature range, resistance to shock and vibration, and long-term data integrity. Procurement teams should note that legacy UV-erasable PROMs face increasing obsolescence pressure as original manufacturers reduce support for windowed ceramic packages; sourcing efforts need to verify traceability, authenticity, and any applicable military-grade suffix markings to avoid non-compliant lots. Engineering engagements for this part typically involve careful socketing or window-cover management to preserve field programmability while protecting against accidental erasure.