What the DS1220AD-120+ is and where it fits
The Maxim Integrated DS1220AD-120+ is a 16Kbit non-volatile SRAM (NVSRAM) organized as 2K x 8 bits, with a parallel interface and a 120 ns access time. It combines the fast read/write cycle of a standard SRAM with internal lithium energy cells that preserve data when the supply drops — no external battery or controller needed. The part is housed in a 24-pin EDIP (0.600-inch, 15.24 mm pitch) and operates from a 4.5 V to 5.5 V supply over the commercial temperature range of 0°C to 70°C.
120 ns access time — timing for legacy buses
The 120 ns access time sets the window for the processor to read or write data. The write cycle time is also 120 ns.
NVSRAM vs battery-backed SRAM — no battery replacement
Unlike conventional battery-backed SRAM modules that use a replaceable coin cell, the DS1220AD-120+ integrates non-volatile elements that store data without a user-serviceable battery. The internal lithium cells are sealed and rated for the life of the product. This eliminates scheduled battery swaps and the risk of data loss from a depleted cell.
Active lifecycle — no LTB risk
The DS1220AD-120+ carries an Active product status. There is no last-time-buy or NRND flag, so it remains available for both new designs and production replenishment. The part is also ROHS3 compliant.