STMicroelectronics M41T82RM6F, Real Time Clock, 32bit RAM Serial-2 Wire, Serial-I2C, 8-Pin SOIC

Ultra-low battery supply current of 365 nA
Factory-calibrated accuracy of ±5 ppm typical after 2 reflows (SOX18)
Much better accuracies achievable using built-in programmable analog and digital calibration circuits
2.0 V to 5.5 V clock operating voltage
Counters for tenths/hundredths of seconds, seconds, minutes, hours, day, date, month, year, and century
Automatic switchover and reset output circuitry (fixed reference)
M41T83S: VCC= 3.00 V to 5.50 V
M41T83R: VCC= 2.70 V to 5.50 V
M41T83Z: VCC= 2.38 V to 5.50 V
Serial interface supports I2C bus (400 kHz protocol)
Programmable alarm with interrupt function (valid even during battery backup mode)
Optional 2ndprogrammable alarm available
Square wave output defaults to 32 KHz on power-up (M41T83 only)
RESET (RST) output
Watchdog timer
Programmable 8-bit counter/timer
7 bytes of battery-backed user SRAM
Battery low flag
Low operating current of 80 μA
Oscillator stop detection
Battery or SuperCap™ backup
Operating temperature of –40 °C to 85 °C
Package options
a 16-lead QFN (M41T83)
an 8-lead SOIC (M41T82) or
an 18-lead embedded crystal SOIC (M41T83)