BQ25750EVM: P&O Timer - How to Adjust

Maciej Pietrusinski

Part Number: BQ25750EVM
Other Parts Discussed in Thread: BQ25750, BQ25756

Tool/software:

The Eval Board (BQ25750EVM) GUI gives three options: 0.5s, 1s, and 10s. This is much too slow for my use case. What is the variable that controls that timer in I2C? How small can the period theoretically be?

4 months ago

0 Ethan Galloway 4 months ago

TI__Mastermind 31275 points

Hello Maciej,

The smallest the P&O timer can be is 0.5s. I don't recommend using the P&O timer though. If you are using a solar panel that may be frequently shaded, I recommend using the minimum full panel sweep timer and setting P&O to disabled.

For your application, how fast do you need the P&O timer to operate?

Best Regards,
Ethan Galloway

0 Maciej Pietrusinski 4 months ago in reply to Ethan Galloway

Prodigy 20 points

We're using this with a wind generator, which is driven by the motion of ocean waves, the major wave period we're seeing is 6s, it's largely a sinusoidal motion. An update rate of 10Hz would be good. Higher would be better.

There are a lot of settings, and the names can be a bit cryptic, is there a document that describes each in detail?

Best

Maciej

0 Ethan Galloway 4 months ago in reply to Maciej Pietrusinski

TI__Mastermind 31275 points

Hello Maciej,

Thanks for the new information. The BQ2575X family can't support a update rate that fast.

Maciej Pietrusinski said:
There are a lot of settings, and the names can be a bit cryptic, is there a document that describes each in detail?

We have an FAQ for the part that might help. Let me know if you have any specific questions.

Best Regards,
Ethan Galloway

0 Maciej Pietrusinski 4 months ago in reply to Ethan Galloway

Prodigy 20 points

OK, what is the fastest update rate supported by the BQ2575X family?

Best,

Maciej

0 Ethan Galloway 4 months ago in reply to Maciej Pietrusinski

TI__Mastermind 31275 points

Hello Maciej,

The fastest update rate is 0.5s. I would recommend using an external microcontroller to manually set the VAC_DPM function of the BQ25750 if you need a faster update rate.

Let me know if you have any questions about this.

Also, thanks for your feedback on the P&O adjustment rate. I will write the P&O rate suggestions down.

Best Regards,
Ethan Galloway

0 Maciej Pietrusinski 4 months ago in reply to Ethan Galloway

Prodigy 20 points

Ethan, I'd like to get our electrical engineers involved, as well as the lead on this overall project. What's the best way to include them in the conversation? Can we continue over email?

Maciej

0 Ethan Galloway 4 months ago in reply to Maciej Pietrusinski

TI__Mastermind 31275 points

Hello Maciej,

Thanks for being patient with this. We are about to release an application note for how to perform P&O with an external microcontroller. We should have all this information ready by the end of this week or early next week. Can you wait until then if that works for you?

Also, I removed your email address from this thread. This is a public facing forum and you don't who's going to be scrapping data from the internet.

Best Regards,
Ethan Galloway

0 Ethan Galloway 4 months ago in reply to Ethan Galloway

TI__Mastermind 31275 points

Hello Maciej,

Thanks for being patient with the delay on this application note.

Here is the application note on how to implement external P&O on the BQ25756: https://www.ti.com/lit/an/sluab21/sluab21.pdf

Let me know if you have any questions about this.

Best Regards,
Ethan Galloway

Power management

Power management forum

BQ25750EVM: P&O Timer - How to Adjust