M48T08Y

M48T08 M48T08Y, M48T18 5 V, 64 Kbit (8 Kb x 8) TIMEKEEPER® SRAM Features ■ Integrated ultra low power SRAM, real-time clock, power-fail control circuit, and battery ■ BYTEWIDE™ RAM-like clock access ■ BCD coded year, month, day, date, hours, minutes, and seconds ■ Typical clock accuracy of ±1 minute a month, at 25 °C ■ Automatic power-fail chip deselect and WRITE protection ■ WRITE protect VPFD = power-fail deselect voltage): – M48T08: VCC = 4.75 to 5.5 V; 4.5 V ≤ VPFD ≤ 4.75 V – M48T18/T08Y: VCC = 4.5 to 5.5 V; 4.2 V ≤ VPFD ≤ 4.5 V ■ Software controlled clock calibration for high accuracy applications ■ Self-contained battery and crystal in the CAPHAT™ DIP package ■ Packaging includes a 28-lead SOIC and SNAPHAT® top (to be ordered separately) ■ SOIC package provides direct connection for a snaphat top which contains the battery and crystal ■ Pin and function compatible with DS1643 and JEDEC standard 8 K x 8 SRAMs ■ RoHS compliant – Lead-free second level interconnect 28 1 PCDIP28 battery/crystal CAPHAT™ SNAPHAT® battery/crystal 28 1 SOH28 June 2011 Doc ID 2411 Rev 11 1/31 www.st.com 1 Contents Contents M48T08, M48T08Y, M48T18 1 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2 Operation modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2.1 READ mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 2.2 WRITE mo...