BQ76952: Driving capacity of CHG and DSG

Edward Lee

Intellectual 1655 points

Part Number: BQ76952
Other Parts Discussed in Thread: BQ77905

Dear Expert,

My customer is trying to use four IXYS N type MOSFETs, XFN420N10T(DFETx2 & CFETx2) in their 16-S battery application.

They would like to know whether BQ76952 can drive these MOSFETs?

Thanks

Sincerely,

Edward

over 5 years ago

0 Matt Sunna over 5 years ago

TI__Guru* 81034 points

Hi Edward,

For this MOSFET, Ciss is 47nF which is pretty large. The BQ76952 can drive multiple of these FETs, but switching may be slow. You may need to enhance the turn off timing with a local PNP for faster timing.

There will be an app note coming out in the next few weeks on using multiple FETs in parallel.

Best regards,

Matt

0 Edward Lee over 5 years ago in reply to Matt Sunna

TI__Intellectual 1655 points

Hi Matt,

Thanks for your prompt reply.

We are looking forward to the app note for using multiple FETs in parallel.

Thanks

Sincerely,

Edward

0 Del Ulldemolins over 5 years ago in reply to Matt Sunna

Prodigy 40 points

Hello Matt,

Any update on the app note for driving multiple FETs in parallel?

Many thanks,

Del

0 Matt Sunna over 5 years ago in reply to Del Ulldemolins

TI__Guru* 81034 points

Hi Del,

This app note is still in work. It may be a few more weeks before it is complete since the engineer is working in parallel on multiple projects.

The device will be able to drive the FETs, but switching will be slow due to the high capacitance, so you may want to use a P-channel turn-off device. The charge pump recommended capacitor range for the BQ76952 is limited so turn on is also likely to be slow and does not have an enhancement.

If you have any specific questions we can help answer sooner, please let me know. Here is the link to a similar app note for the BQ77905 protector that might have some helpful information: https://www.ti.com/lit/pdf/slua773

This app note is also a good reference: https://www.ti.com/lit/ml/slua618a/slua618a.pdf

Regards,

Matt

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BQ76952: Driving capacity of CHG and DSG