BUY DS1643-120 https://www.utsource.net/itm/p/236003.html
Nonvolatile Timekeeping RAM
Description: The DS1643-120 is a static Random Access Memory (SRAM) manufactured by Dallas Semiconductor. The device is a 2Kb Non-volatile SRAM and is available in a DIP-28 package. It contains a non-volatile controller and supports a 10-year data retention in the absence of power. Features: 2Kb Non-volatile SRAM Small 28-pin DIP package 10-year data retention Low voltage operation Fast access times Self-contained batteries Low-battery detection Hardware write-protection 100,000 minimum write/erase cycles Fully static operation Applications: The DS1643-120 SRAM is suitable for applications that require static memory, non-volatility and data retention. It is typically used in systems requiring high reliability. This includes automotive systems, medical equipment, computer peripherals, industrial control, embedded systems and consumer electronics. (For reference only)