BQ76930: BQ76930: CHG MOSFET Back to Back

user5182420

Prodigy 20 points

Part Number: BQ76930
Other Parts Discussed in Thread: BQ76200

Dear Sir,

As you see circuit, CHG MOSFET may I use back to back circuit?

Please you kindly review circuit & advise if my circuit is error.

Thanks!

Steven

over 5 years ago

0 Matt Sunna over 5 years ago

TI__Guru* 80773 points

Hi Steven,

I have not seen this configuration before. If the purpose is to allow more current, then I would recommend configuring the FETs in parallel.

The configuration you show above has the two FETs facing the opposite way. The one facing the wrong way will also prevent current flow in discharge.

Matt

0 Steven He92 over 5 years ago in reply to Matt Sunna

Expert 2125 points

Dear Matt,

My customer would just turn off CHG side when short circuit happen. so let's design back to back MOSFET structure in CHG.

if this circuit error could you provide a right circuit to us reference.

Thanks!

Steven

0 Matt Sunna over 5 years ago in reply to Steven He92

TI__Guru* 80773 points

Hi Steven,

The CHG pin of the BQ76930 is not activated for a short circuit condition, only the DSG FET is turned off. Here are the links to 5 different reference designs using the BQ769x0 family:

http://www.ti.com/tool/TIDA-00449

http://www.ti.com/tool/TIDA-00792

http://www.ti.com/tool/TIDA-01093

http://www.ti.com/tool/TIDA-010030

http://www.ti.com/tool/TIDA-00255

The datasheet for the BQ76930 shows the typical configuration and there is more information in the FET Drive section of this app note: http://www.ti.com/lit/an/slua749a/slua749a.pdf

If they were to use the BQ76200 high side driver, there is also this app note available with multiple different FET configurations: http://www.ti.com/lit/pdf/slva729

Best regards,

Matt

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BQ76930: BQ76930: CHG MOSFET Back to Back