Super Capacitor Working Time Calculator
Used for trickle charge RTC. This calculator determines the operating time in the time hold state when the supercapacitor is powered based on the capacitor's starting and ending voltages, discharge current and capacitance.
Supercapacitor Working Time
Maximum Vcap corresponds to the maximum value of VCC, which can be found in the relevant data sheet, that is: (VCC maximum) - (diode voltage drop)
Minimum Vcap is the minimum value of the RTC oscillator operating voltage, which can be found in the relevant data sheet.
Maximum IBAT is the maximum current of the battery, which can be found in the relevant data sheet.
Typical IBAT is the typical battery current defined at 25°C and nominal supply voltage, which can be found in the relevant data sheet.
Maximum VBAT is the maximum voltage on the VBAT pin, which can be found in the relevant data sheet
Maximum IBAT and Typical IBAT are used to calculate the operating time (hours) under maximum IBAT and typical IBAT. When calculating the operating time, it is assumed that the IBAT current remains constant and the voltage on the battery input pin does not need to be considered.
When calculating the operating time under linear IBAT, it is assumed that the oscillator current is proportional to the input voltage, that is, it exhibits a resistive characteristic. The equivalent resistance of the circuit is calculated using the maximum IBAT and maximum VBAT values provided in the data sheet, which is used to calculate the battery backup time.