About the meaning of "Years of retention is 20 years or more"

Question:

I read from the presentation material of nvSRAM that "Years of retention is 20 years or more" in nvSRAM. Can you explain about the year of retention? Will the stored value in the NVSRAM vanish when the capacitor loses its charge?

 

Answer:

When the power goes down, the data stored in nvSRAM is STORED in the non-Volatile memory. The NVSRAM memory can retain data for 20 years (at the specified temperature), without any external power supply.

The capacitor charge is used for STORING the data during accidental power down (Auto-Store). This STORE cycle typically takes less than 10ms, after which NVSRAM memory can retain the data without any capacitor charge.