Energy Harvester SPV1050 / STEVAL-ISV019V1: When connecting > 4-6uF on the LDO output, the LDO voltage collapses

DKlin.2 · ‎2021-05-02

I'm currently prototyping with the Steval-ISV019V1 (evaluation board for SPV1050) and have only changed the resistor ladder for MPPT. Energy harvesting works nice.

But when I enable one of the LDOs and have > 4-6uF connected on the LDO output, the LDO voltage collapses to around 0,8V. When I remove the capacitive load it takes a few seconds until it is possible to enable the LDO again and it starts working normal (stable 3.3V output).

Is this a normal behaviour of the SPV1050? I suppose not, may the chip is destroyed?

May someone can help with its knowledge?

Thanks!

DKlin.2 · ‎2021-05-03

Update: I'm not able to measure it, but the problem seems to be the current spike at t0 when connecting the capacitor (even it is a very small one).

When I add a 33Ohm resistor (theoretical I max = 100mA) in serial to the capacitive load the LDOs voltage is and stays stable.