Datasheet

M4T28-BR12SH, M4T32-BR12SH Description
5/16
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
Table 1. Signal names
X1 Crystal input
X2 Crystal output
V
BAT–
Negative voltage
V
BAT+
Positive voltage
AI02528
SNAPHAT
V
BAT–
V
BAT+
X1 X2