M48T02 M48T12 5.0 V, 16 Kbit (2 Kb x 8) TIMEKEEPER SRAM Features Integrated, ultra low power SRAM, real-time clock, and power-fail control circuit 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 Software controlled clock calibration for high accuracy applications Automatic power-fail chip deselect and WRITE 24 protection 1 WRITE protect voltages (V = power-fail deselect voltage): PFD M48T02: V = 4.75 to 5.5 V CC 4.5 V V 4.75 V PFD M48T12: V = 4.5 to 5.5 V PCDIP24 CC battery/crystal 4.2 V V 4.5 V PFD CAPHAT Self-contained battery and crystal in the CAPHAT DIP package Pin and function compatible with JEDEC standard 2 K x 8 SRAMs RoHS compliant Lead-free second level interconnect June 2011 Doc ID 2410 Rev 9 1/25 www.st.com 1Contents M48T02, M48T12 Contents 1 Description . 5 2 Operation modes 7 2.1 READ mode 7 2.2 WRITE mode . 9 2.3 Data retention mode . 10 3 Clock operations . 12 3.1 Reading the clock . 12 3.2 Setting the clock 12 3.3 Stopping and starting the oscillator . 13 3.4 Calibrating the clock . 13 3.5 V noise and negative going transients . 16 CC 4 Maximum ratings . 17 5 DC and AC parameters 18 6 Package mechanical data 21 7 Part numbering 22 8 Environmental information . 23 9 Revision history . 24 2/25 Doc ID 2410 Rev 9