Hi,
I would like to use the BQ25504 with a 0.7V input voltage and increase it to 3v without using a battery on the Bat pin.
Initially I’m using BQ25504 EVM to do some tests with a 0.9V power supply and 0.2A maximum current (so Pin_max = 0.2W).
I just connected the power supply with a series resistor at the input and the load at the output (VSTOR pin).
My problem is: when I put a 3kohms load on the VSTOR pin, the output voltage doesn't stay steady at 3.1V, it drops to 2.4V (with 10kohms it works). I don't know why because the power supply can provide more power.
Here is a screenshot from a oscilloscope. The red one is the Vbat and the blue one is the VSTOR with 3kohms.
Do you know where this problem is coming from?
Thank you!