M4T28-BR12SH1 Battery Type, STMicroelectronics M4T28-BR12SH1, Battery Backup IC, 2.8 V 4-Pin, SNAPHAT

SNAPHAT® Lithium Coin Cell Battery with Crystal, STMicroelectronics/
These Battery and Crystal Option devices are detachable lithium power sources housed in special top called SNAPHAT®. The SNAPHAT is snapped on the top of the surface-mounted IC in the Printed Circuit board. Also compatible with the non-volatile TIMEKEEPER® package by STMicroelectronics.
M4Txx-BR12SH SNAPHAT/
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.
Features and Benefits/
ulliProvides battery backup power for serial real-time clock, non-volatile TIMEKEEPER®and supervisor devices in the 28- or 44-pin SNAPHAT®SOIC package/liliRemovable battery avoids heat associated with surface-mount process/liliSnaps directly onto surface-mounted SNAPHAT SOIC/liliChoice of battery capacities:/li/ul- M4T28-BR12SH = 48 mAh - M4T32-BR12SH = 120 mAhulliKeyed insertion to ensure proper assembly/liliRemovable for replacement and proper disposal/liliPb-free package/liliAvailable in Ecopack®packages, tubes/li/ul