M48T02 M48T12 5.0 V, 16 Kbit (2 Kb x 8) TIMEKEEPER® SRAM is a low power real-time clock chip from ST company. It features BCD coded year, month, day, date, hours, minutes and seconds. The typical clock accuracy is ±1 minute/month at 25°C and supports software controlled clock calibration and automatic power-fail chip deselect and write protection.