M4TXX-BR12SH
MECHANICAL INFORMATION
Table 1. Description
Parameter
Electrical connection to the SOIC is made through
four pins that connect to the four press fitted sock-
ets at each end of the SOIC. Critical contact
points between the pins and sockets are gold-plat-
ed to resist oxidation. Internally, each socket con-
tains six independent contact fingers to form
redundant connections between the two compo-
nents. These sockets were designed with high
point contact force to provide the lowest possible
contact resistance. The SNAPHAT top also incor-
porates four molded-in retaining clips which hold
onto the ends of the SOIC insuring mechanical
and electrical connection even under severe me-
chanical shock and vibration. The combined SOIC
and SNAPHAT assembly can sustain shock levels
in excess of 100 g without separating. This pack-
age also passes variable frequency testing in ac-
cordance with MIL-STD-883, method 2007.2,
condition A.
Value
1 = 0 to 70 °C
Operating
Temperature
6 = –40 to 85 °C
Storage
Temperature
–40 to 85 °C
Nominal Crystal
Frequency
32.768 kHz
12.5 pF
2.8 V
Load Capacitance
Nominal
Battery Voltage
Nominal
Battery Capacity
48 mAh
120 mAh
M4T28
M4T32
Battery Chemistry
Li(CF)x
Figure 2 illustrates the affect of repeated insertion
and extraction of the SNAPHAT top to the SOIC.
The force required to extract the SNAPHAT, and
then to re-insert it, reduces each time. After three
or four extractions, though, the reduction starts to
become unnoticeable, and the force required
remains at a fairly constant figure. Typically,
though, the SNAPHAT will only need to be
extracted and re-inserted once in its lifetime.
acteristically flat voltage level supplied by the bat-
tery until very near the end of its life. These
discharge levels have been greatly accelerated in
comparison to the normal, actual usage.
UL RECOGNITION
The M4Txx-BR12SH has been recognized by Un-
derwriters Laboratories under their Component
Recognition Program and carries U.L. File Num-
ber E89556.
BATTERY CHARACTERISTICS
Figure 3 illustrates the lithium coin cell discharge
rate for a given load. This demonstrates the char-
Figure 2. SNAPHAT Insertion/Extraction Forces
20
7.5
5
12.5
10
Average Insertion Force
Average Extraction Force
7.5
5
2.5
0
1
2
3
4
5
6
7
8
9
10
Number of Extractions
AI02526
2/7
STMICROELECTRONICS [ ST ]
