Patent ID: 8838187

Claim:
An electric quantity detecting circuit, comprising: a battery, a voltage comparator, a first resistor, a second resistor and a third resistor, wherein an anode of the battery is connected with an Analog-to-Digital Converter (ADC) of an Application Processor (AP) module, and a cathode of the battery is series connected with the first, second and third resistors in series and then grounded; and the voltage comparator is connected with the cathode of the battery and configured to determine an upper electric quantity limit and a lower electric quantity limit according to the resistance values of the first, second and third resistors and detect whether the battery electric quantity is low according to the upper electric quantity limit and the lower electric quantity limit; wherein the voltage comparator comprises an input terminal and a comparing unit, wherein the input terminal is configured to input the upper electric quantity limit between the first and second resistors, and input the lower electric quantity limit between the second and third resistors, the upper electric quantity limit is 1.240×(R 1 +R 2 +R 3 )/(R 2 +R 3 ), and the lower electric quantity limit is 1.240×(R 1 +R 2 +R 3 )/R 3 , wherein R 1 , R 2 and R 3 are resistance values of the first, second and third resistors, respectively; and the comparing unit is configured to determine that the electric quantity is low when the batter electric quantity is determined to be in the ran se between the upper electric quantity limit and the lower electric quantity limit, and determine that the electric quantity is high when the battery electric quantity is determined to be out of the range between the upper electric quantity limit and the lower electric quantity limit.