CY7C271-35WMB

The CY7C271-35WMB is a 32K x 8 power-switched and reprogrammable PROM from Cypress Semiconductor, providing non-volatile memory storage with a 35 ns access time in a windowed CERDIP-28 package. This CMOS device integrates automatic power switching that reduces standby current when the chip is deselected, optimizing power consumption in array-intensive designs. The quartz window allows the memory array to be fully erased using ultraviolet light and then electrically reprogrammed, making it suitable for prototyping, field-upgradeable firmware, and applications requiring occasional code updates.

Typical deployments include boot code and embedded firmware storage in military avionics, missile guidance systems, satellite subsystems, and high-reliability industrial controllers that demand radiation-tolerant, long-life non-volatile memory. The windowed CERDIP package and the WMB suffix indicate a military temperature range (typically -55°C to +125°C) and hermetic construction consistent with MIL-STD-883 screening. As a legacy Cypress device, the CY7C271 series has reached end-of-life, introducing obsolescence risk for sustainment programs. Procurement relies on verified existing inventories or certified aftermarket channels. Engineers supporting extended lifecycle platforms should confirm date code integrity, authentic package markings, and proper storage history when sourcing these UV-erasable PROMs to preserve programming reliability and continued compliance with system qualification baselines.