The CY7C128A-25PC is a 16Kbit (2K x 8) asynchronous SRAM from Cypress, in a 24-PDIP package. Its 25 ns access time is the critical timing parameter for interfacing with legacy 8-bit microprocessors and controllers that expect a fast memory response without wait states.
Obsolete — how to source it today
That means new-production factory orders are not an option. Supply is limited to surplus and broker-channel inventory — typically pulled from old-stock trays or reels.
Commercial temp range — indoor use only
Not rated for automotive, industrial, or outdoor environments where extended temperature or humidity cycling is present.
Asynchronous interface — no clock, simple glue
As an asynchronous SRAM, the CY7C128A-25PC uses address and control signals (CE, OE, WE) without a clock. This simplifies the bus interface for processors that do not have a dedicated memory clock or for designs where timing is handled by combinatorial logic. The 25 ns write cycle time matches the read access, allowing symmetric read/write performance.
Standard 0.100" pitch DIP footprint. No exposed pad or thermal management features — the plastic DIP relies on ambient airflow for cooling. MSL rating is typical for through-hole DIPs (MSL 1 or 3, not specified here).