ST M4T28-BR12SH, M4T32-BR12SH User Manual
Features
M4T28-BR12SH
M4T32-BR12SH
TIMEKEEPER® SNAPHAT® (battery and crystal)
■ Provides battery backup power for non-volatile
TIMEKEEPER
28- or 44-pin SNAPHAT
■ Removable battery avoids heat associated with
®
and supervisor devices in the
®
SOIC package
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 or tape
& reel
SNAPHAT (SH)
battery/crystal
November 2008 Rev 3 1/16
www.st.com
1
Contents M4T28-BR12SH, M4T32-BR12SH
Contents
1 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2 Maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3 DC and AC parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
4 Mechanical information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
4.1 Battery characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4.2 UL recognition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4.3 Battery life . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4.4 General notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
5 Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
6 Part numbering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
7 Environmental information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
8 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
2/16
M4T28-BR12SH, M4T32-BR12SH List of tables
List of tables
Table 1. Signal names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Table 2. Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Table 3. Operating and AC measurement conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Table 4. SH – 4-pin SNAPHAT® housing for 48 mAh battery & crystal, package mechanical data 11
Table 5. SH – 4-pin SNAPHAT® housing for 120 mAh battery & crystal,
package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Table 6. Ordering information scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Table 7. Document revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
3/16
List of figures M4T28-BR12SH, M4T32-BR12SH
List of figures
Figure 1. Logic diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Figure 2. SNAPHAT® insertion/extraction forces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Figure 3. Battery discharge rates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Figure 4. DIP extractor tool . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Figure 5. SH – 4-pin SNAPHAT® housing for 48 mAh battery & crystal, package outline . . . . . . . . 11
Figure 6. SH – 4-pin SNAPHAT® housing for 120 mAh battery & crystal, package outline . . . . . . . 12
Figure 7. Recycling symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
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M4T28-BR12SH, M4T32-BR12SH Description
1 Description
The M4TXX-BR12SH SNAPHAT® top is a detachable lithium power source for ST’s non-
volatile TIMEKEEPER
®
surface-mount SOIC (MH) 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.
Figure 1. Logic diagram
X1 X2
SNAPHAT
V
BAT–VBAT+
Table 1. Signal names
X1 Crystal input
X2 Crystal output
V
V
BAT–
BAT+
Negative voltage
Positive voltage
AI02528
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