M41ST85WMX6F STMICROELECTRONICS [STMicroelectronics], M41ST85WMX6F Datasheet - Page 18

• Manufacturer Part Number: M41ST85WMX6F
• Description: 3.0/3.3V I2C combination serial RTC, NVRAM supervisor and microprocessor supervisor
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

Operating modes
M41ST85W
If data retention lifetime is a critical parameter for the system, it is important to review the
data retention current specifications for the particular SRAMs being evaluated. Most SRAMs
specify a data retention current at 3.0 volts. Manufacturers generally specify a typical
condition for room temperature along with a worst case condition (generally at elevated
temperatures). The system level requirements will determine the choice of which value to
use. The data retention current value of the SRAMs can then be added to the I
value of
BAT
the M41ST85W to determine the total current requirements for data retention. The available
®
battery capacity for the SNAPHAT
top of your choice can then be divided by this current to
determine the amount of data retention available (see
Table 19 on page
39).
For a further more detailed review of lifetime calculations, please see Application Note
AN1012.
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