STMicroelectronics M41ST85WMH6E

Description
The STM41ST85W3 is a 12C combination serial RTC, NVRAM supervisor, and microprocessor supervisor. It features automatic battery switchover and write protection for internal serial RTC and external low power SRAM (LPSRAM). The device operates at 3.0/3.3 V and has an ultralow battery supply current of 500 nA (max).

Features
400 kHz 12C serial interface
3.0/3.3 V operating voltage
Ultralow battery supply current of 500 nA (max)
44 bytes of general purpose NVRAM
Counters for seconds, minutes, hours, day, date, month, year, century, tenths/hundredths of seconds
Programmable alarm with repeat modes
Power-down timestamp (HT bit)
2.5 to 5.5 V oscillator operating voltage
Programmable watchdog with 62.5 ms to 128 s time-out period
Early power-fail warning circuit (PFI/PFO) with 1.25 V precision reference
Power-on reset/low voltage detect with open drain reset output
Reset voltage, VPFD = 2.60 V (nom)
Two reset input pins
Watchdog can be steered to reset output
Non-volatizes external LPSRAM
Power-fail deselect (write protect) voltage, VPFD 2.60 V (nom)
Switchover, Vso = 2.50 V (nom)
Battery monitor (battery low flag)
Programmable squarewave generator (1 Hz to 32 KHz)
-40°C to 85°C operation

Applications
Real-time clocks
Data loggers
Security systems
Industrial control
Medical devices
Automotive electronics