STMicroelectronics | M41T94MH6F

The M41T94MH6F is a low power serial SPI bus real-time clock (RTC) with 44 bytes NVRAM and reset, built-in 32.768 kHz oscillator, available in SOIC-28 package.

It has built-in power sense circuit which detects power failures and automatically switches to the battery supply when a power failure occurs. The energy needed to sustain the clock operations can be supplied by a small lithium.

Features:

• Counters for tenths/hundredths of seconds, seconds, minutes, hours, day, date, month, year, and century
• 32 kHz crystal oscillator integrating load capacitance (12.5 pF) providing exceptional oscillator stability and high crystal series resistance operation
• Serial peripheral interface (2 MHz SPI)
• Ultralow battery supply current of 500 nA (max)
• 2.7 to 5.5 V operating voltage
• 2.5 to 5.5 V oscillator operating voltage
• Battery low flag
• Automatic switchover and deselect circuitry
• 44 bytes of general purpose RAM
• Programmable alarm and interrupt function (valid even during battery backup mode)
• Accurate programmable watchdog timer (from 62.5 ms to 128 s)
• Microprocessor power-on reset
• Choice of power-fail deselect voltages
• (VCC = 2.7 to 5.5 V):
  • THS = VSS; 2.55 V ≤ VPFD ≤ 2.70 V
  • THS = VCC; 4.20 V ≤ VPFD ≤ 4.50 V
• Packaging includes a 28-lead SOIC and SNAPHAT® top (to be ordered separately) or 16-lead SOIC
• 28-lead SOIC package provides direct connection for a SNAPHAT® top which contains the battery and crystal
• RoHS compliant
• Lead-free second level interconnect