Patent ID: 7915863
Filing Date: 2011-03-29
Classification: H02J

Abstract:
1. A charge protection circuit with a timing function for protecting a lithium-ion battery from being overcharged, comprising: a battery protection module comprising a control integrated circuit having a overcharge control terminal, a charge delay trigger terminal, a second capacitor connected to the charge delay trigger terminal, and a second Switch controlled to be on or off by the overcharge control terminal; and a timing circuit comprising a first operational amplifier, a second operational amplifier, and a first capacitor, wherein the first operational amplifier outputs a first high level signal during charging of the lithium-ion battery to charge the first capacitor, which consequently raise a voltage applied to the second operational amplifier, the second operational amplifier outputs a second high level signal to charge the second capacitor, when the voltage applied thereto exceeds another voltage concurrently applied to the second operational amplifier, the first capacitor raises a voltage applied to the charge delay trigger terminal of the control integrated circuit and signals the control integrated circuit to switch off the second switch when the voltage applied to the charge delay trigger terminal reaches a predetermined value, thereby preventing the lithium-ion battery from being overcharged.