M4TXX-BR12SH
TIMEKEEPER SNAPHAT (Battery & Crystal)
■ Provides Battery Backup Power for Non-Volatile
TIMEKEEPERs and Controllers in the
SNAPHAT SOIC Package
■ Removable Battery Avoids Heat Associated
with Surface Mount Process
■ Snaps Directly onto Surface-Mounted
SNAPHAT SOIC
■ Choice of Battery Capacities
– M4T28-BR12SH = 48 mAh
– M4T32-BR12SH = 120 mAh SNAPHAT (SH)
Battery & Crystal
■ Keyed Insertion to Insure Proper Assembly
■ Removable for Replacement and Proper
Disposal
■ Available in Tubes or Tape & Reel
■ For Use with the 28 and 44 pin SOIC Versions
of the TIMEKEEPER Product Families Figure 1. Logic Diagram
DESCRIPTION
The M4Txx-BR12SH SNAPHAT top is a detach-
able lithium power source for ST’s non-volatile
TIMEKEEPER surface mount SOIC (MH) pack-
age (28 and 44 pin).
The SNAPHAT top contains both the battery and X1 X2
crystal and is designed to be "snapped on" after
the SOIC is surface mounted on the PC board.
Thus the two piece solution avoids the battery and
crystal from having to be exposed to the high tem-
peratures of the surface mount process.
SNAPHAT
VBAT– VBAT+
AI02528
November 1999 1/7
M4TXX-BR12SH
MECHANICAL INFORMATION Table 1. Description
Electrical connection to the SOIC is made through Parameter Value
four pins that connect to the four press fitted sock-
ets at each end of the SOIC. Critical contact Operating 1 = 0 to 70 °C
points between the pins and sockets are gold-plat- Temperature 6 = –40 to 85 °C
ed to resist oxidation. Internally, each socket con-
tains six independent contact fingers to form Storage
redundant connections between the two compo- –40 to 85 °C
Temperature
nents. These sockets were designed with high
point contact force to provide the lowest possible Nominal Crystal
32.768 kHz
contact resistance. The SNAPHAT top also incor- Frequency
porates four molded-in retaining clips which hold
onto the ends of the SOIC insuring mechanical Load Capacitance 12.5 pF
and electrical connection even under severe me-
chanical shock and vibration. The combined SOIC Nominal
2.8 V
Battery Voltage
and SNAPHAT assembly can sustain shock levels
in excess of 100 g without separating. This pack-
Nominal 48 mAh M4T28
age also passes variable frequency testing in ac- Battery Capacity 120 mAh M4T32
cordance with MIL-STD-883, method 2007.2,
condition A. 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 acteristically flat voltage level supplied by the bat-
or four extractions, though, the reduction starts to tery until very near the end of its life. These
become unnoticeable, and the force required discharge levels have been greatly accelerated in
remains at a fairly constant figure. Typically, comparison to the normal, actual usage.
though, the SNAPHAT will only need to be
extracted and re-inserted once in its lifetime. UL RECOGNITION
The M4Txx-BR12SH has been recognized by Un-
BATTERY CHARACTERISTICS derwriters Laboratories under their Component
Figure 3 illustrates the lithium coin cell discharge Recognition Program and carries U.L. File Num-
rate for a given load. This demonstrates the char- ber E89556.
Figure 2. SNAPHAT Insertion/Extraction Forces
20
7.5
5 Average Insertion Force
Average Extraction Force
12.5
Force (pounds)
10
7.5
2.5
0
1 2 3 4 5 6 7 8 9 10
Number of Extractions
AI02526
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M4TXX-BR12SH
Figure 3. Battery Discharge Rates
LOAD CHARACTERISTICS Temp: 20˚C
3.5
3.0
Voltage (V)
2.5
2.0
15kΩ 30kΩ 100kΩ
1.5
1.0
0 200 400 600 800 1000 1200 1400 1600 1800 2000
Duration (hrs.)
(A)
LOAD CHARACTERISTICS Temp: 20˚C
3.5
3.0
Voltage (V)
2.5
2.0
15kΩ 30kΩ 50kΩ 100kΩ
1.5
1.0
0 1000 2000 3000 4000 5000 6000
Duration (hrs.)
(B) AI02519
BATTERY LIFE Figure 4. DIP Extractor Tool
For information on Data Retention Life and Battery
Storage Life, please refer to the Application Note
AN1012.
GENERAL NOTES
To remove the SNAPHAT top for replacement, a
DIP/IC extractor tool should be used.
Caution: To avoid draining battery do NOT place
AI02527
SNAPHAT pins in a conductive foam.
Caution: To avoid damaging SNAPHAT sockets
do NOT wave solder SOIC.
For battery disposal information, see on the web at
www.rayovac.com.
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M4TXX-BR12SH
Table 2. Ordering Information Scheme
Example: M4T28-BR12 SH 1
Product Family
M4T = SNAPHAT Battery & Crystal
Battery Voltage & Capacity
28-BR12 = BR1225, 3 V, 48 mAh
32-BR12 = BR1632, 3 V, 120 mAh
Package
SH = SNAPHAT
Temperature Range
1 = 0 to 70 °C
6 = –40 to 85 °C
For further information on any aspect of this device, please contact the STMicroelectronics Sales Office
nearest to you.
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M4TXX-BR12SH
Table 3. M4T28-BR12SH - TIMEKEEPER 4-pin SNAPHAT Housing for 48 mAh Battery & Crystal,
Package Mechanical Data
mm inches
Symb
Typ Min Max Typ Min Max
A 9.78 0.385
A1 6.73 7.24 0.265 0.285
A2 6.48 6.99 0.255 0.275
A3 0.38 0.015
B 0.46 0.56 0.018 0.022
D 21.21 21.84 0.835 0.860
E 14.22 14.99 0.560 0.590
eA 15.55 15.95 0.612 0.628
eB 3.20 3.61 0.126 0.142
L 2.03 2.29 0.080 0.090
Figure 5. M4T28-BR12SH - TIMEKEEPER 4-pin SNAPHAT Housing for 48 mAh Battery & Crystal,
Package Outline
A1 A2
A A3
eA B L
eB
D
SHTK-A
Drawing is not to scale.
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M4TXX-BR12SH
Table 4. M4T32-BR12SH - TIMEKEEPER 4-pin SNAPHAT Housing for 120 mAh Battery & Crystal,
Package Mechanical Data
mm inches
Symb
Typ Min Max Typ Min Max
A 10.54 0.415
A1 8.00 8.51 0.315 0.335
A2 7.24 8.00 0.285 0.315
A3 0.38 0.015
B 0.46 0.56 0.018 0.022
D 21.21 21.84 0.835 0.860
E 17.27 18.03 0.680 0.710
eA 15.55 15.95 0.612 0.628
eB 3.20 3.61 0.126 0.142
L 2.03 2.29 0.080 0.090
Figure 6. M4T32-BR12SH - TIMEKEEPER 4-pin SNAPHAT Housing for 120 mAh Battery & Crystal,
Package Outline
A1 A2
A A3
eA B L
eB
D
SHTK-A
Drawing is not to scale.
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M4TXX-BR12SH
If you have any questions or suggestions concerning the matters raised in this document, please send
them to the following electronic mail addresses:
apps.nvram@st.com (for application support)
ask.memory@st.com (for general enquiries)
Please remember to include your name, company, location, telephone number and fax number.
Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the consequences
of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No license is granted
by implication or otherwise under any patent or patent rights of STMicroelectronics. Specifications mentioned in this publication are subject
to change without notice. This publication supersedes and replaces all information previously supplied. STMicroelectronics products are not
authorized for use as critical components in life support devices or systems without express written approval of STMicroelectronics.
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