M4T28-BR12SH1TR STMICROELECTRONICS [STMicroelectronics], M4T28-BR12SH1TR Datasheet - Page 3

• Manufacturer Part Number: M4T28-BR12SH1TR
• Description: TIMEKEEPER SNAPHAT (BATTERY & CRYSTAL)
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

SUMMARY DESCRIPTION
The M4TXX-BR12SH SNAPHAT
able lithium power source for ST’s non-volatile
TIMEKEEPER
age (28- and 44-pin).
Figure 2. Logic Diagram
®
V BAT–
surface-mount SOIC (MH) pack-
X1
SNAPHAT
V BAT+
X2
®
top is a detach-
AI02528
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 tem-
peratures of the surface mount process.
Table 1. Signal Names
X1
X2
V
V
BAT–
BAT+
M4T28-BR12SH, M4T32-BR12SH
Crystal Input
Crystal Output
Negative Voltage
Positive Voltage
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