Timekeeper nvram and serial rtc st m41t00m6e real time clock yy mm dd date format hh mm ss time format serial i2c interface 250ns data setup time 100khz clock frequency 35ppm frequency precision 2v to 5 5v supply voltage 40 to 85 c 8 soic case the m41t00 is a low power serial real time clock with a built in 32 768 khz oscillator 8 bytes of the ram are used for the clock calendar function and are configured in bcd format supplied in tube st m41t00m6e s08 real time clock y2k i2