The M41T81SM6E is a low-power serial real-time clock (RTC) with a built-in 32.768 kHz oscillator (external crystal controlled). 

• Counters for tenths/hundredths of seconds, seconds, minutes, hours, days, dates, months, years, and century

  
  

• 32 KHz crystal oscillator with integrated load capacitance (12.5 pf) which provides exceptional oscillator stability and high crystal series resistance operation)

  
  

• Oscillator stop detection (monitors clock operation)

  
  

• Serial interface supports I²C bus (400 kHz protocol)

  
  

• Ultra-low battery supply current of 0.6 µA (type)

  
  

• 2.0 to 5.5 V clock operating voltage

  
  

• Automatic switchover and deselect circuitry (fixed reference) which provides full operation in 3.0 V applications)

  
  

• V_CC = 2.7 to 5.5 V

  
  

• 2.5 V ≤ V_PFD ≤ 2.7 V

  
  

• Power-down time-stamp (HT bit) which allows determination of time elapsed in battery backup

  
  

• Battery low flag

  
  

• Programmable alarm and interrupt function (valid even during battery backup mode)

  
  

• Accurate programmable watchdog timer (from 62.5 ms to 128 s)

  
  

• Software clock calibration (to compensate for crystal deviation due to temperature)

  
  

• Operating temperature of –40 to 85 °C

  
  

• Package options include an 8-lead SOIC or 18-lead embedded crystal SOIC

  
  

  
  

  
  

  M41T81SM6E Applications

  
  

  • Industrial

    
    

  • General Uses 

    
    

    
    

    Mount	Surface Mount
    Mounting Type	Surface Mount
    Package / Case	8-SOIC (0.154, 3.90mm Width)
    Number of Pins	8
    Operating Temperature	-40°C~85°C
    Packaging	Tube
    JESD-609 Code	e4
    Feature	Alarm, Leap Year, Square Wave Output, Watchdog Timer
    Part Status	Obsolete
    Moisture Sensitivity Level (MSL)	1 (Unlimited)
    Number of Terminations	8
    ECCN Code	EAR99
    Type	Clock/Calendar
    Terminal Finish	Nickel/Palladium/Gold (Ni/Pd/Au)
    Voltage - Supply	2.7V~5.5V
    Terminal Position	DUAL
    Peak Reflow Temperature (Cel)	260
    Supply Voltage	5V
    Frequency	32kHz
    Time@Peak Reflow Temperature-Max (s)	30
    Base Part Number	M41T81
    Pin Count	8
    Number of Outputs	1
    Power Supplies	3/5V
    Interface	I2C, 2-Wire Serial
    RAM Size	20B
    Logic Function	Clock
    Number of Timers	1
    Time Format	HH:MM:SS:hh (24 hr)
    Date Format	YY-MM-DD-dd
    Current - Timekeeping (Max)	100μA @ 2.7V~5.5V
    Interrupt Capability	Y
    Voltage - Supply, Battery	2V~3.5V
    Volatile	YES
    Information Access Method	I2C
    Height	1.25mm
    Length	5mm
    Width	4mm
    REACH SVHC	No SVHC
    Radiation Hardening	No
    RoHS Status	ROHS3 Compliant
    Lead Free	Lead Free