BQ25820EVM: Need design files for BQ25820EVM, and sister device information

Hello Klaus,

Klaus Kragelund said:

I notice that the schematics and layout seems to be coming from Altium. Is it possible for you to share those files, that will make it a lot easier to make the first revision of our board.

I will send the files through email.

Klaus Kragelund said:

As for the design, we would like to have options due to supply chain considerations. Does a sister/former device exist that has almost the same functionality as the BQ2580, maybe even here design files in Altium?

This when depend on your requirements and what functionality you are interested in.

What is your input voltage?

What is your battery voltage?

Do you have a system load?

Do you need a host controlled device( I2C/SMBus), or do you need a standalone device?

Klaus Kragelund said:

Lastly, does calculation sheet exist that is linked to the BQ25820EVM, if we need to tweak the design, or calculated derating, that would come in handy

You can download the design calcuator for BQ25756( this is similar to BQ25820, except it's a buck-boost charger without direct power path.:www.ti.com/.../

Best Regards,

Christian.

Sounds very good with the files.

We have input voltage of 48V, could select lower, say 36V. This comes from an ac->DC converter.

Then we use the buck charge converter, BQ25820, to charge a Lithium battery with 28.8V nominal (24V min, 33.6V max)

After this we have another buck converter, LM5128, that will provide steady voltage to the system load.

So basically, the above system is a ac UPS, with output voltage that can be set to anything from 0V to 24V (minimum voltage during low SOC of the battery)

The system load is nominally 50W, sometimes as high as 160W, though only for 10 seconds.

The offline converter is over 250W, in order to charge the batteries in 4-5 hours (1200Wh battery)