NVSRAM with 70 ns access — what it means for the bus
The DS1225AB-70+ is a 64Kbit non-volatile SRAM from Maxim Integrated, organised as 8K x 8 bits with a parallel interface and a 70 ns access time. It combines the fast read/write cycle of a standard SRAM with non-volatile storage — data is retained when power is removed, without requiring a battery or EEPROM write cycle. This makes it a fit for applications that need to preserve calibration constants, configuration tables, or boot parameters across power cycles, while still allowing byte-wide random access at SRAM speeds. The 70 ns access time is the key timing parameter: it defines the minimum read-cycle time the host controller must allow, and it matches the bus timing of many legacy 8-bit microcontrollers and DSPs that expect a 70 ns or slower memory. If your controller's memory bus runs faster than 70 ns, you will need to insert wait states or look at a faster NVSRAM variant.
Lifecycle and sourcing reality
For a BOM line that needs this exact part, there is no forced migration risk today. It is an active, ROHS3-compliant part.