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6 years, 10 months ago.
SIM900 CR2032 rtc battery backup
I would like to use a CR2032 battery to power the internal RTC of the SIM900 gsm module. The datasheet (given in the link) says that the battery should be rated at 3V. They also give the following reference circuit for non-rechargable batteries (like CR2032).
this is the date sheet of CR2032:http://www.componentschip.com/details/Panasonic-BSG/CR2032.html
I am confused about the diode in this circuit. As far as I know the forward voltage drop of a diode is 0.7V at average, which leaves only 2.3V for the RTC. Will that cause any problems, knowing that the datasheet says the battery should be rated at 3V?