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When does VCC go into battery back up mode?
When Vcc falls below the Battery Back-up Switchover Voltage (V so ), the device goes into battery back-up mode, and draws all its current from the battery. The Vcc duty cycle represents the proportion of time, expressed as a percentage, that the device is supplied with power from the external supply, and hence not drawing current from the battery.
When does V CC draw all the current from the battery?
When V cc is being held by the external power supply within its specified range, the current drawn from the battery is zero. When Vcc falls below the Battery Back-up Switchover Voltage (V so ), the device goes into battery back-up mode, and draws all its current from the battery.
How to calculate the life of a battery?
Capacity consumption is simply calculated by: – I bat is measured in amperes. To calculate the typical and worse case data retention lifetimes, select the Serial RTC Device and then enter the battery capacity of your choice in the form below (in mAh), and click on Calculate.
How is the VCC duty cycle is calculated?
The Vcc duty cycle represents the proportion of time, expressed as a percentage, that the device is supplied with power from the external supply, and hence not drawing current from the battery. Capacity consumption is simply calculated by:
Is the ds3231 IC a real time clock?
ZS-042 is a real time clock module with DS3231 IC. Find out if it can be powered at 3.3 V and 5 V and whether you can use CR2032 or LIR2032 backup battery. I’m working on a project which requires an RTC clock.
When does RTC start working on ds3231 battery?
Current from power supply will start flowing through battery only when its voltage drops below 2.7 V. The RTC still works as long as battery voltage is above 2.3 V. As a conclusion, when powered at 3.3 V the module behaves good, except battery charging does not work (no matter what battery type you use).
What should voltage be for ds3231 battery charger?
Issues appear when using a supply voltage of 5 V. You should definitely use a LIR2032 cell and make sure your voltage supply does never get higher than 4.7 volts to allow a safe voltage for the cell in the case of 0.5 V drop across diode. If using the 3.3 V supply voltage I wouldn’t worry at all.