MP3362 - General doubts from the datasheet

Hi all,

I have found some doubts while going through the MP3362 datasheet. These doubts/questions are briefly described next:

  1. The “Selecting the Inductor” section (page 13) indicates that the converter must operate in CCM. Therefore, DCM is not possible in the MP3362? In that case, is it due to the internal controller implementation? Because, in principle, peak current mode control can also be achieved (easily) in DCM.

  2. The Gea parameter (transconductance of the internal error amplifier) has two different values along the datasheet. In page 5, the typical value is 250uA/V, but in page 14 the value is 350uA/V. Maybe this last one is a typo, right?

  3. I couldn’t find the numeric value of the Gcs parameter (conductance of the internal current sense circuit) in the datasheet. Gcs is defined in page 14, below equation (16), but I couldn’t find its value anywhere.

  4. Which is the criteria to select the crossover frequency (fc)? Normally, fc is chosen between 1/5 to 1/10 smaller than the switching frequency, but in this case it must be below 1/3 of the RHPZ frequency. However, depending on the design parameters, this could be not too far away from the switching frequency. Could anyone elaborate on this?

Thank you in advance for your time!

Best regards,
Juan

1 Like

Hi Juan,

I am sorry about the late response to this. There have been changes made to the DS since then. The latest version as of 9.19.2023 is rev 1.1 from 2.22.2023.

Please reach out to MPS NOW Remote Support - Support (monolithicpower.com). We will be better able to support you there regarding the compensation.

If your operation is similar to our EVB application, then you can try copying: EVQ3362-J-00A | Single-String, 3V VIN_MIN, 36V VOUT, Boost LED Driver Evaluation Board, AEC-Q100 | MPS (monolithicpower.com).

Regards,
Vinh Tran