M41T94_07 Datasheet, PDF (1/41 Pages) STMicroelectronics – Serial real-time clock with 44 bytes NVRAM and reset

M41T94
Serial real-time clock with 44 bytes NVRAM and reset
Features
■ Counters for tenths/hundredths of seconds,
seconds, minutes, hours, day, date, month,
year, and century
■ 32KHz crystal oscillator integrating load
capacitance (12.5pF) providing exceptional
oscillator stability and high crystal series
resistance operation
■ Serial peripheral interface (2MHz SPI)
■ Ultra-low battery supply current of 500nA (max)
■ 2.7 to 5.5V operating voltage
■ 2.5 to 5.5V 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 back-up mode)
■ Accurate programmable watchdog timer (from
62.5ms to 128s)
■ Microprocessor power-on reset
■ Choice of power-fail deselect voltages
(V_CC = 2.7 to 5.5V):
– THS = V_SS; 2.55V ≤ V_PFD ≤ 2.70V
– THS = V_CC; 4.20V ≤ V_PFD ≤ 4.50V
■ 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
16
1
SO16 (MQ)
SNAPHAT (SH)
battery & crystal
28
1
SOH28 (MH)
November 2007
Rev 5
1/41
www.st.com
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