BUY MT4C4001JDJ-7 https://www.utsource.net/itm/p/1827114.html
standard or self refresh
Package: SOJ20 Description: The MT4C4001JDJ-7 is a 4Mb (512K x 8) CMOS Static RAM. It is organized as 512K words by 8 bits. It is fabricated using advanced CMOS technology for high speed and low power operation. Features: High speed access time: 70ns Low power consumption: Active current: 45mA (max) Standby current: 10μA (max) Single 5V power supply TTL compatible inputs and outputs Fully asynchronous operation CMOS power saving standby mode Data retention voltage: 2.0V (min) Applications: Automotive Industrial Medical Consumer Networking Embedded systems (For reference only)