BQ76952: TIDA-010208 10s-16s Battery Pack reference design

mehmet özel

Prodigy 70 points

Part Number: BQ76952
Other Parts Discussed in Thread: TIDA-010208

Tool/software:

Hello,

I have a question about document TIDA-010208 (10s-16s Battery Pack reference design).

I couldn't understand why there is a D38 zenner diode and what the function of this zenner is.

Also, I don't understand what the Q29 mosfet circuit does, I guess it is a protection circuit? is it?

My battery structure is 1P15S LFP and discharge current is max 100A, charge is max 20A.

So, can I use this mosfet driver circuit (reference design circuit) in my own design?

Please help me,

https://www.ti.com/tool/TIDA-010208?keyMatch=TIDA-010208

Regards,

Mehmet

10 days ago

0 Thomas Rainey 10 days ago

TI__Expert 3120 points

Hi Mehmet,

The D38 zenner diode is to clamp the gate source voltage at 5.1V.

The Q29 MOSFET circuit is used to hold the gate of the discharge power FET at the source potential to keep it off when the PACK+ terminal is pulled below VSS. For more information on the MOSFET circuit you can refer to Multiple FETs with the BQ76952, BQ76942 Battery Monitors (Rev. A) application note.

Following TIDA-010208 exactly may not work for your structure. TIDA-010208 is designed for a reverse charger and has a max discharge current of 27A. You can refer to Design Guide: TIDA-010208 for more information on the system specifications.

Best regards,

Thomas Rainey

0 mehmet özel 9 days ago in reply to Thomas Rainey

Prodigy 70 points

Hi Thomas,
First of all, thank you for sharing.
I know the d38 is to clamp gate source voltage but I would like to know what is the function of Q28 pmos fet, I don't understand this circuit.What was this circuit used for?

Couldn't we drive like the attached figure?