Battery protection circuit
AssigneeTexas Instruments Incorporated
InventorKatsura Yoshio
Life of this patent
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Abstract
A protection of battery system having battery cells Cell1˜Cell3, FET switches SW1, SW2 that are connected to the high-side path and control on/off state of the path, as well as fuse F1 for cutting said path, primary protection circuits 31˜34 that detect abnormalities in charging/discharging of the battery cells and turn the FET switches off, and secondary protecting controller 38 that detect abnormalities in charging/discharging of the battery cells and controls the operation of fuse F1. Secondary protecting controller 38 controls fuse F1 if there is no tendency to a decrease in abnormalities after a prescribed period of time after control of the FET switch.
Claims19
A battery protection circuit used to control the operation of a first switch circuit and a second switch circuit inserted in series in a power supply path between battery cells and an external power source, comprising a first protecting controller, having an interface circuit for receiving a command signal output from a controller monitoring whether the voltage of the battery cells is higher than a first voltage, and generating a control signal for controlling operation of the first switch circuit,
- a second protecting controller, having an over-voltage detector that detects whether the voltage of the battery cells is higher than a second voltage or higher than the first voltage, and generating a control signal for controlling the operation of the first switch circuit and a second control signal for controlling the turning off of the second switch circuit;
- wherein, when the over-voltage detector of the second protecting controller detects that the voltage of the battery cells is higher than said second voltage, a control signal for turning off the first switch circuit is generated;
- then, when the voltage of the battery cells remains higher than the second voltage after a prescribed time, the second control signal is generated for turning off the second switch circuit.
Dependencies are inferred from the claim text.