What is the minimum VIN voltage to maintain a stable 3.15V on SW2 of the PF0100 PMIC?

[nathanpalmer]

I don't see in the datasheet where it shows the minimum voltage difference between the VIN and VOUT for the various switchers and LDOs on the PF0100.  I assume it is in the manual but I cannot find it anywhere.  It just says VIN must be "higher" than VOUT but does not say by how much.   I would like to run the VIN at 3.3V and still get 3.15 out but I don't know if that is possible.

[JorgeRama_rezRi · Accepted solution]

Hi Nathan,

Please see MMPF0100 datasheet rev 7.0. This information is kind of hidden, but it's all there:

- VGEN1 and VGEN2: Are not a problem. Max output is 1.55V and min input is 1.75V.

- VGEN3 - VGEN6: Input must be 0.25V higher than the output.

- SW1: Is not a problem since max output is 1.875V and min input is 2.8.

- SW2 - SW4: Can do 100% duty cycle. The datasheet has notes on how to calculate the headroom required. You can find these notes below each switcher electrical characteristics table:

    The higher output voltages available depend on the voltage drop in the conduction path as given by the following equation:

    (VINSW2 - VSW2) = ISW2* (DCR of Inductor +RONSW2P + PCB trace resistance).

Best regards.

Jorge.