Since the beginning of NV SRAM development, the intent has been to produce a hybrid memory product that could be handled exactly like an IC. Use of a commodity low-power SRAM with a lithium coin-cell battery mated CMOS wafer technology with a common, voltage-stable source for long-term memory backup power.

In order to understand the design criteria defining Maxim/Dallas’ new single-piece module (SPM) package, as well as the selection of Manganese Lithium (ML) secondary (rechargeable) battery chemistry for the energy source, it is first necessary to comprehend a bit of the history of battery-backed memory products. This application note provides this historical background.