BQ40Z80: Parallel capacitor at PBI pin

SAERO

Part Number: BQ40Z80
Other Parts Discussed in Thread: CSD18510Q5B

Hello,

Is it okay to add parallel capacitor at PBI pin?

I'm planning to use 10uF and 0.1uF in combination. I have been reading many posts that 10uF is recommended to driver more parallel fets. I have communication loss sometimes during discharge. This communication loss is rare and happens for a 1 or 2 secs. Looking for suggestion whether using 10uF is fine or whether there are drawbacks to using higher capacitance.

Thank you.

over 2 years ago

+1 Wyatt Keller over 2 years ago

TI__Guru** 105810 points

Hello Saero,

Yes you can add capacitors in parallel on PBI, it is used in case of quick power draws from the gauge. This will add better frequency response.

How many cells in series are you testing with?

Sincerely,

Wyatt Keller

0 SAERO over 2 years ago in reply to Wyatt Keller

Intellectual 361 points

I'm testing on 6S pack with 4x CSD18510Q5B mosfets in series.

0 Wyatt Keller over 2 years ago in reply to SAERO

TI__Guru** 105810 points

Hello Saero,

Please also reduce the max simulation iterations to 20 as well for 6s applications.

Sincerely,

Wyatt Keller

0 SAERO over 2 years ago in reply to Wyatt Keller

Intellectual 361 points

Wyatt Keller said:
max simulation iterations to 20 as well

Hey Wyatt,
Can you explain this? Where can I find more information this?

thank you

0 Wyatt Keller over 2 years ago in reply to SAERO

TI__Guru** 105810 points

Hello Saero,

In some applications that use 6s there can be periodic watchdog events due to the gauge running multiple capacity simulations for all the cells, by reducing this to 20 these will no longer occur.

Sincerely,

Wyatt Keller

0 SAERO over 2 years ago in reply to Wyatt Keller

Intellectual 361 points

Is default 30 or 25? Currently I have it at 25.
20 is optimal?
Thank you!

0 Wyatt Keller over 2 years ago in reply to SAERO

TI__Guru** 105810 points

Hello Saero,

IT should be set to 20 for 6s configuration for optimal performance. Regardless if the default is 25 or 30.

Sincerely,

Wyatt Keller

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BQ40Z80: Parallel capacitor at PBI pin