Voltage droop after Tsample of SPV1050 Voltage Input

[DLiu.3]

Hi there,

I am having a problem connecting SPV1050 to a 6V solar power, in order to charge one 3.7V battery. From joulescope screenshot attached, it shows that its input voltage starts to droop slowly after MPPT Tsample finished, instead of quickly returning to desired MPP ratio (in my case 85%).

Can anyone advise what could be causing that droop, and how to resolve it? I first suspected it was due to the 10nF cap at MPP_REF which might be leaking, but replacing the cap didn't seem to help.

Thanks,

Dawei

[DLiu.3]

Here is the scopeshot.

[Domenico RAGONESE]

Dear Dawei,

I'm assuming you're using one of the application boards (STEVAL) available on st.com.

Could you let me know which board code are you using?

If you're using your own design, could you share the schematic, please?

I agree that the waveform seem reporting a leakage and there are different possibilities:

• leakage from the input capacitor. You could add a 22uF at input stage.
• leakage from the internal circuitry of the SPV1050 (in this case the p/n can be damage)
• .. ?

Please, take into account that from tomorrow, and until the next two weeks, our reply could be strongly delayed due to season holidays.

Best Regards,

Domenico.