Can the IC SPV1040T charge a lithium Ion battery on its own with the circuitry provided by the eDesignSuite? Second question: is it possible to test the MPPT functionality of this IC without a solar panel (with a lab DC power supply for example)?

[Peter BENSCH]

Welcome, @TDe.1​, to the community!

The SPV1040 is called battery charger, but this does not refer to lithium cells. Their end-of-charge voltage must be regulated very precisely, which the SPV1040 is not able to do.

However, there is an application note AN4050 that describes a charger for LiIO batteries using an SPV1040 and a following L6924D (LiIO charger).

A solar cell is not an ideal voltage source, so it is not easy to test an MPPT converter on a laboratory power supply without additional precautions. However, you could simulate an internal resistance of the power supply with a series resistor, behind which the MPPT algorithm should then be able to work. You could dimension the resistor according to the maximum power point, i.e. R=Vmp/Imp. But please make sure that you do not exceed the maximum input voltage of the SPV1040.

Does it answer your question?

Regards

/Peter

[TDe.1]

Hello Peter,

Thank you for the fast reply! I will try to look into this L6924D charger.

If I understand correctly, the output of the SPV1040 will be a constant voltage, depending on the resistor divider. So without connecting a load (leaving the Vbatt+ floating), one would expect to be able to measure this voltage, is this correct?

Another question, in the datasheet it is stated that there are different working modes (Soft-start, Start-up mode, MPPT mode) based on the Vout. How would this work with a L6924D charger IC connected to Vbatt?

Greetings,

Tim

Greetings Tim

[Peter BENSCH]

Correct, if the energy from the solar panel is sufficient, the output will be a constant voltage, which can also be measured at Vbatt.

For the function of the L6924D together with the SPV1040, it is best to look at the information on the associated STEVAL-ISV012V1 and the data sheet of the L6924D, where, among other things, the different charging phases of the L6924D are described.

Regards

/Peter

[TDe.1]

@Peter BENSCH​ , one more question, what is the absolute maximum power output of this IC? The eDesignSuite can go to 5V 1.7A, but in the datasheet I found PoutMAX = 3W.

Greetings Tim

[Peter BENSCH]

The data sheet also has footnote 2 when stating the max 3W, in which some additional information is given, including the reference to the power dissipation and the thermal resistance. The eDesignSuite can also only simulate what it knows, which includes, for example, the thermal resistance of the board and possible cooling systems.

Regards

/Peter