DS1221 Datasheet - Dallas

DS1221 Nonvolatile Controller x 4 Chip

A, B CE CE0 - CE3 VBAT1 VBAT2 * RST VCCI VCCO * RD * WE *D/Q - Address Inputs - Chip Enable Input - Chip Enable Outputs - + Battery 1 - + Battery 2 - Reset - +5V Supply - RAM Supply - Read Inpu - Write Input - Data Input/Output DS1221 16-Pin SOIC (300-mil) See Mech. Drawings Secti.

DS1221 Features

* Converts CMOS RAMs into nonvolatile memories Data is automatically protected during power loss 2-to-4 decoder provides for up to 4 CMOS RAMs Provides for redundant batteries Test battery condition on power-up Full ±10% operating range Unauthorized access can be prevented with optional security featu

DS1221_Dallas.pdf