Data Sheet

AN1012 TIMEKEEPER products
Doc ID 6395 Rev 4 17/33
5.2.4 M48T35 and M48T37V/Y
The M48T35 and M48T37V/Y families use the same technology as the M48T58 device, but
with a 32K x 8 SRAM array. Figure 10 and Figure 11 show the expected battery lifetime
versus temperature. The expected battery lifetime (at 30 °C with no periods of valid V
CC
) is
typically 6.8 years (this assumes that a 48 mAh battery is used, see Figure 10). Devices in
the larger M4T32-BR12SH SNAPHAT
®
package have a data retention lifetime of greater
than twice this (almost 17 years, see Figure 11).
Figure 10. M48T35/37V/37Y data retention lifetime vs. temperature (48 mAh, 100%
battery backup)
Figure 11. M48T35/37V/37Y data retention lifetime vs. temperature (120 mAh, 100%
battery backup)