BQ25703A: bq25703a _Ilim

Hey Belhaj,

The VDDA voltage should be approximately 6V. You calculated 2.6V as the ILIM_HIZ voltage. Use the resistor voltage divider equation to select R308 and R310. Select the resistors to be in the tens of kiloOhms or hundreds of kiloOhms order of magnitude.


Regards,
Joel H

Hey Belhaj,

That looks appropriate to me. I will make one important note, however:

If at any point the output voltage AND input voltage of the charger is less than 6V (VBUS <6V, VSYS <6V, VBAT<6V), then this calculation will be different as the VDDA voltage will also be less than 6V by default.


Regards,
Joel H

Hey Belhaj,

Then you need to readjust the VDDA part of the calculation to approximately 5V, instead of 6V.

From there, recalculate your resistor divider network.


Regards,
Joel H

Hey Belhaj,

The VDDA value is directly equal to the REGN voltage.

I will refer you to the Electrical Characteristics table under the "REGN REGULATOR" section to give you an idea of the dropout voltage on VDDA with a 5V input and a 20mA load on REGN. If the load is very light, you can expect the voltage to be closer to VDDA.


Regards,
Joel H