M4T28-BR12SH M4T32-BR12SH Real-time clock and TIMEKEEPER SNAPHAT battery with crystal Datasheet - production data Description The M4Txx-BR12SH SNAPHAT top is a detachable lithium power source for STs 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 SNAPHAT battery with crystal temperatures of the surface-mount process. 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 February 2014 DocID013125 Rev 4 1/16 This is information on a product in full production. www.st.comContents M4T28-BR12SH, M4T32-BR12SH Contents 1 Device overview 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 DocID013125 Rev 4