Battery protection circuit

Patent metadata

Field	Value
Publication number	US-2016301224-A1
Application number	US-201514879058-A
Country	US
Kind code	A1
Filing date	Oct 8, 2015
Priority date	Apr 10, 2015
Publication date	Oct 13, 2016
Grant date	—

Abstract

An exemplary embodiment of the present invention provides a battery protection circuit including a battery, a fuse, a charging switch including a first body diode that is forward biased in a discharge path direction, a discharging switch including a second body diode that is forward biased in a charge path direction, a thermistor including a first end and a second end, the first end being coupled between the charging switch and the discharging switch, and a controller configured to sense a voltage value from the second end of the thermistor, and configured to control the fuse, the charging switch, and the discharging switch.

First claim

What is claimed is:

1 . A battery protection circuit comprising:
a battery; a fuse; a charging switch comprising a first body diode that is forward biased in a discharge path direction; a discharging switch comprising a second body diode that is forward biased in a charge path direction; a thermistor comprising a first end and a second end, the first end being coupled between the charging switch and the discharging switch; and a controller configured to sense a voltage value from the second end of the thermistor, and configured to control the fuse, the charging switch, and the discharging switch.

2 . The battery protection circuit of claim 1 , wherein the first end of the thermistor comprises a heat-conductive pattern.

3 . The battery protection circuit of claim 2 , wherein the controller is configured to perform a protection function, the protection function comprising:
sensing damage of the charging switch or of the discharging switch by sensing voltage variation corresponding to resistance variation of the thermistor; and blowing the fuse.

4 . The battery protection circuit of claim 2 , wherein the controller is configured to perform a first protection function, the first protection function comprising:
turning off the discharging switch in an over-discharge prevention mode; and turning off the charging switch in an overcharge prevention mode.

5 . The battery protection circuit of claim 4 , wherein the controller is configured to:
detect that the first protection function is improperly performed by sensing voltage variation corresponding to resistance variation of the thermistor; and perform an additional protection function by blowing the fuse.

6 . The battery protection circuit of claim 5 , wherein a thermistor resistance of the thermistor changes when a temperature of at least one of the charging switch and the discharging switch increases.

7 . The battery protection circuit of claim 6 , further comprising:
a comparative resistor comprising a first end and a second end, the first end being coupled to a reference voltage node, and the second end being coupled to the controller, wherein the controller is configured to detect that the first protection function is improperly performed by comparing a first voltage sensed through the comparative resistor and a second voltage sensed through the thermistor.

8 . The battery protection circuit of claim 7 , wherein a comparative resistor resistance of the comparative resistor is matched with the thermistor resistance of the thermistor by reflecting a resistance value of at least one element between one end of the thermistor and one end of the comparative resistor.

Assignees

• Samsung Sdi Co Ltd

Inventors

• Kim Young-Jun

Classifications

• H02J7/65

  against overtemperature · CPC title

• H02J7/63

  against overdischarge · CPC title

• H02J7/61

  against overcharge · CPC title

• H02J7/663 Primary

  using battery or load disconnect circuits (H02J9/002 takes precedence) · CPC title

• H01M10/443

  in response to temperature · CPC title