Voltage detection circuit, the overcurrent detection circuit, the charge current control system, and a voltage detection method

摘要

PROBLEM TO BE SOLVED: To solve the problem that detection values output from a voltage detecting circuit are varied by variations in relative error components of a plurality of resistors for dividing an input voltage, variations in input offset components of a voltage amplifier for amplifying an input minute voltage and variations in input offset components of a comparator for comparing an amplified voltage value whether it is not less than a certain level, in the case the detected voltage value is too minute in the voltage detecting circuit.;SOLUTION: The input voltage is detected two times at a first period and a second period by using a switch circuit and a sampling circuit, and detected values are averaged. In this case, the variations in the relative error components of the plurality of resistors for dividing the input voltage, the variations in the input offset components of the voltage amplifier for amplifying the input minute voltage, and the variations in the input offset components of the comparator for comparing the amplified voltage value whether it is not less than the certain level, are subjected to an addition process respectively such that their positive/negative polarizations at the first and second periods are opposite to each other. Therefore, only effective components of the object voltage to be detected can be detected precisely.;COPYRIGHT: (C)2006,JPO&NCIPI