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
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
(V
CC
= 2.7 to 5.5 V):
– THS = V
SS
; 2.55 V
≤
V
PFD
≤
2.70 V
– THS = V
CC
; 4.20 V
≤
V
PFD
≤
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
SNAPHAT
®
(SH)
battery & crystal
SO16 (MQ)
16
1
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28
1
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SOH28 (MH)
■
January 2009
Rev 6
1/41
1
STMICROELECTRONICS [ STMICROELECTRONICS ]
