M41T01M6F STMicroelectronics

M41T01 Low-power serial real-time clock (RTC) with built-in battery switchover circuit Datasheet - production data Description The M41T01 is a low-power serial real-time clock 8 (RTC). The built-in 32.768 kHz oscillator circuit works with an external crystal and does not need 1 any load capacitors. SO8 The M41T01 clock has a built-in power sense circuit which detects power failures and automatically switches to the battery supply during power failures. Eight bytes of the RAM are Features used for the clock/calendar function and are 2.0 to 5.5 V clock operating voltage configured in binary-coded decimal (BCD) format. Addresses and data are transferred serially via a Counters for seconds, minutes, hours, day, two-line bidirectional bus. The built-in address date, month, years, and century register is incremented automatically after each Software clock calibration WRITE or READ data byte. The energy needed to Automatic switchover and deselect circuitry sustain the RAM and clock operations can be supplied from a small lithium coin cell. Ultra-low battery supply current of 800 nA Low operating current of 300 A Typical data retention time is in excess of 5 years with a 50 mA/h 3 V lithium cell. The M41T01 is Battery and capacitor backup supplied in an 8-lead plastic small outline Battery backup not recommended for 3.0 V package. applications (capacitor backup only) Operating temperature of 40 to 85 C Automatic leap year compensation October 2013 DocID025389 Rev 2 1/24 This is information on a product in full production. www.st.comContents M41T01 Contents 1 Device overview 5 2 Operation 7 2.1 2-wire bus characteristics 7 2.2 READ mode . 10 2.3 WRITE mode 12 2.4 Data retention mode . 12 3 Clock operation 13 3.1 Clock calibration 15 3.2 Output driver pin 16 3.3 Initial power-on defaults 16 4 Maximum rating 17 5 DC and AC parameters 18 6 Package mechanical information . 21 7 Part numbering 22 8 Revision history . 23 2/24 DocID025389 Rev 2