MP2617BGL-Z Voltage Issue in PCB : Unable to Achieve 4V on Vout Pin Using USB Power

[rahul]

Dear Team,

I am experiencing an issue with my schematic when supplying power via USB (5V input). The Vout pin is not reaching the expected 4V, even though I have configured the voltage divider (R11 = 25.5kΩ and R16 = 10kΩ). Currently, the SYS pin voltage is 3.6V, but I need it to be 4V.

Could you please review the schematic and suggest any modifications to achieve the desired 4V output? Also, please note that I am supplying power only through USB and have not connected a battery.

Thank you for your assistance.

[Krishan.FAE]

Hello Rahul,

What is the SoC and voltage of the battery? Vsys is not completely a regulated voltage output. Vsys stays at 3.6V whenever Vbatt is equal or lower than 3.4V. Then Vsys follows Vbatt afterwards according to this.

[Krishan.FAE]

Nothing appears wrong with the schematic here. Please review the functional cases for Vsys (as outlined in the datasheet):

If this needs to be a regulated voltage that doesn’t fluctuate, I would highly recommend using a buck-boost IC that MPS can also support with.

Best,

Krishan