Patent ID: 8773073
Filing Date: 2014-07-08
Classification: H02H,H02J

Abstract:
1. A battery protection circuit for protecting a secondary battery composed of a first cell and a second cell, comprising: a reference voltage supply circuit that outputs a first reference voltage and a second reference voltage generated based on a cell voltage of the first cell and a cell voltage of the second cell, respectively; a first detection circuit that outputs a signal prohibiting charging when at least one of the cell voltages of the first cell and the second cell exceeds a predetermined overcharge indication value indicating an overcharge condition, and outputs a signal permitting charging when none of the cell voltages of the first cell and the second cell exceed the predetermined overcharge indication value; a second detection circuit that outputs a signal prohibiting charging when at least one of the first reference voltage and the second reference voltage is not within a predetermined target range, and outputs a signal permitting charging when all of the first reference voltage and the second reference voltage are within the predetermined target range; and a control circuit that controls a switch for allowing a flow of a charging current to the secondary battery based on the output from the first detection circuit and the second detection circuit such that charging of the secondary battery is prohibited when at least one of the outputs from the first detection circuit and the second detection circuit is the signal prohibiting charging, and charging of the secondary battery is permitted when all of the outputs from the first detection circuit and the second detection circuit are the signal permitting charging.