bq40z60 CHG FET description in datasheet

Sunil Panchal

Other Parts Discussed in Thread: BQ40Z60

Refer below quoted text from Page 27 of SLUSAW3C bq40z60 datasheet.

"If the average discharge current is high, the system can turn ON the CHG FET for improved efficiency and minimized line losses during the discharge phase."

This statement is wrong. CHG FET is N-channel MOSFET. It can not allow current to flow in reverse direction. The discharge current will flow from diode of CHG FET and DSG FET only.

over 9 years ago

0 ThomasCosby over 9 years ago

TI__Guru 73830 points

Sunil,

All of the gauge devices will turn the CHG FET on if discharge current it detected. This reduces the voltage drop across the FET and reduces heating.

Tom

0 Sunil Panchal over 9 years ago in reply to ThomasCosby

Prodigy 30 points

Thanks Tomas

I got it. The reason you gave may not be correct that it will reduce the drop across the FET and reduce heating.

The reason could be "As soon as Discharge starts, Gauge finds that the battery pack is not at its full capacity(as it started discharging) so it will try to charge and thus it will enable CHG FET."

Sunil

0 ThomasCosby over 9 years ago in reply to Sunil Panchal

TI__Guru 73830 points

Sunil,
The reason that I provided, "that it will reduce the drop across the FET and reduce heating", is the correct reason that we enable the CHG FET when the pack starts discharging,
Tom

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bq40z60 CHG FET description in datasheet