A 4Mb Pseudo SRAM Operating At 2.6//sup +/sub -//1V With 3/spl mu/A Data Retention Current

This 4Mb pseudo-static ram (PSRAM) has a 3μA data-retention current (DRC) and a 2.6±1V operating voltage.1.2 This PSRAM with 3μA DRC allows a 20MB ram disk to retain data for 2 months with a button-shaped 190mAh lithium battery (20x3.2mm). The 2.6±1V operating voltage is compatible with voltages such as 2.6 to 3.6V from a lithium battery or 2.4V from two Ni-Cad cells. The ±lV range voltage accommodates the discharge-charge characteristics of batteries.