We have a new design for a low power solar powered outdoor device. We are noticing very high switching boost current in low power and no load conditions. For example, when no load is on vout the burst mode is presumably on, causing 100hz spikes of several hundred mA, bringing an average idle current to 10mA. When low power MCU attached, similar condition. Is this expected? Does this chip family support ultra low power, or do I need another chip for the low power provisions?
Hello Zach, welcome to the MPS Forums.
You should be seeing the following quiescent current at no load conditions:
Do you perhaps have a schematic that you can show for review?
For further reference, here is an image of our typical application:
What is your Vin, expected Vsys output voltage, and light load currents you are seeing this behavior at?
Hi Krishan, this is helpful thank you.
We’ve tried no load and MCU_on load which is 250mA, both have these 300mA spikes at varying periodic time intervals. We tried pulling the mode pin low to reduce the boost effect at light loads but that did not have the effect we hoped. Do you see any issues with our schematic?
I compared your schematic to our typical application schematic as shown in the MP2636 datasheet (and above). After double checking what you have provided with our reference, it seems you have followed the schematic quite diligently.
EV2636-R-00A | Full Power Management IC For Single-Cell Battery System | MPS
If you replicated the conditions with an EV2636, this would point out differences in the layout if this behavior doesn’t continue to persist, further isolating what could be causing this issue.