M4T28_32-BR12SH.fm
Document overview
- Manufacturer or author: STMICROELECTRONICS
- PDF pages: 16
Technical content
Datasheet sections
- 1 Device overview
- 2 Maximum ratings
- 3 DC and AC parameters
- 4 Mechanical information
- 4.1 Battery characteristics
- 4.2 UL recognition
- 4.3 Battery life
- 4.4 General notes
- 5 Package mechanical data
- 6 Part numbering
- 7 Environmental information
- 8 Revision history
Features
- Provides battery backup power for serial real- time clock, non-volatile TIMEKEEPER ® and supervisor devices in the 28- or 44-pin 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
- Keyed insertion to ensure proper assembly
- Removable for replacement and proper disposal
- Pb-free package
- Available in Ecopack ® packages, tubes
Description
The M4Txx-BR12SH SNAPHAT ® top is a detachable lithium power source for ST’s serial real-time clock and non-volatile TIMEKEEPER surface-mount SOIC package (28- and 44-pin). The SNAPHAT top contains both the battery and crystal and is designed to be “snapped on” after the SOIC is surface mounted on the PC board. Thus the two-piece solution prevents the battery and crystal from being exposed to the high temperatures of the surface-mount process. SNAPHAT ® battery with crystal
Table 4. SH – 4-pin SNAPHAT® housing for 48 mAh batt ery & crystal, Table 5. SH – 4-pin SNAPHAT® housing for 120 mAh bat tery & crystal,
1 Device overview
Figure 1. Logic diagram Table 1. Signal names
2 Maximum ratings
extended periods may affect device reliability. Table 2. Absolute maximum ratings Caution: Do NOT wave solder SOIC to avoid damaging SNAPHAT sockets.
- Only the M4T32-BR12SH is available in industrial temperature (grade 6).
3 DC and AC parameters
the measurement conditions when using the quoted parameters. Table 3. Operating and AC measurement conditions
4 Mechanical information
in accordance with MIL-STD-883, method 2007.2, condition A. to be extracted and re-inserted once in its lifetime. Figure 2. SNAPHAT ® insertion/extraction forces
M4T28-BR12SH, M4T32-BR12SH Mechanical information
4.1 Battery characteristics
Figure 3 on page 10 illustrates the lithium coin cell discharge rate for a given load. This demonstrates the characteristically flat voltage level supplied by the battery until very near the end of its life. These discharge levels have been greatly accelerated in comparison to the normal, actual usage. Note: These batteries contain no mercury (Hg), cadmi um (Cd), or lead (Pb).
4.2 UL recognition
The M4Txx-BR12SH has been recognized by Underwriter s Laboratories under their Component Recognition Program and carries U.L. File Number E89556.
4.3 Battery life
For information on data retention life and battery storage life, please refer to the application note AN1012.
4.4 General notes
ST has conducted experiments using a manual press which determined that if approximately 60 pounds of force is applied to the top of the SNAPHAT ®, battery damage and/or die cracks could be induced. As Figure 2 on page 8 specifies, only an average of less than 13 force-pounds is required for proper insertion. We recommend that no more than 40 pounds of force be applied during SNAPHAT insertion. If a manual press in employed, it is very important that it be calibrated such that it cannot exceed this limit. To remove the SNAPHAT top for replacement, a DIP/IC extractor tool should be used (see Figure 4 ). The SNAPHAP top should be grabbed by the narrow end to avoid bending the pins. Caution: To avoid draining battery do NOT place SNAPHAT pins into conductive foam. Caution: To avoid damaging SNAPHAT sockets do NOT wave solder SOIC.
5 Package mechanical data
specifications, grade definitions and product status are available at: www.st.com . Figure 5. SH – 4-pin SNAPHAT ® housing for 48 mAh battery & crystal, package outline Note: Drawing is not to scale. Table 4. SH – 4-pin SNAPHAT ® housing for 48 mAh battery & crystal, package mechanical data
Figure 6. SH – 4-pin SNAPHAT ® housing for 120 mAh battery & crystal, package outline Note: Drawing is not to scale. Table 5. SH – 4-pin SNAPHAT ® housing for 120 mAh battery & crystal, package mechanical data
6 Part numbering
Table 6. Ordering information scheme of this device, please contact the ST sales office nearest to you.
7 Environmental information
Figure 7. Recycling symbols button cell battery fully encapsulated in the final product. and local/national disposal and recycling regulations.
8 Revision history
Table 7. Document revision history