CY7C271-55WMB

The CY7C271-55WMB is a 256 Kbit (32K x 8) power-switched ultraviolet-erasable programmable read-only memory (UV EPROM) manufactured by Cypress Semiconductor, designed for high-reliability embedded storage. Fabricated in a 28-pin windowed ceramic dual in-line package (CERDIP), the device provides a 55 ns access time and incorporates automatic power-switching circuitry that reduces standby current consumption when the chip is deselected, an important consideration in power-constrained or thermally sensitive designs. The quartz window on the ceramic package allows the memory array to be fully erased via UV light and electrically reprogrammed, making it suited for iterative firmware development, field calibration updates, and applications where non-volatile code must be revised without replacing the component.

Typical applications span aerospace guidance modules, defense communication hardware, and industrial controllers where radiation-tolerant, non-volatile program storage is required for boot code, look-up tables, or embedded processor firmware. The windowed CERDIP construction also supports qualification and extended-temperature operation expected in mil-spec and high-reliability environments. Procurement of this EPROM involves managing the component’s legacy status; Cypress has discontinued many mature UV EPROM families, so long-term availability depends on aftermarket or authorized redistribution channels. Engineering and supply-chain teams should validate date-code authenticity and environmental handling history, as ceramic-windowed devices demand electrostatic and contaminant precautions during programming and deployment to avoid premature bit corruption or erasure window damage.