MPM3810A - Stability and Pspice query

Automotive Solutions
1

Hi,

We are using MPM3810A.
1)In the datasheet pg no:16, it was given that the R1 should be between 40kohm to 80kohm as a design trade off between stability and dynamics. In pgno 4, the maximum feedback current is given as 1uA. When 40kohm is used, then an additional 40mV will get added to my output. My load IC requirement is very tight. Hence R1 is made as 1kohm and R2 is made as 2kohm. It will pass with the latter values. Whether this is allowable? Whether it will impact the load transient and stability of the converter?

2)The MPM3810 pspice model provided in the website is producing error in pspice. The screenshot is attached. Please do the needful
image

Thanks

2

Hi,
Please see answers below:

  1. There would be concerns for stability issues if R1 is out of the range of the 40k-80kohms. It is recommended to keep within this range.

  2. Were any parameters changed when you ran the simulation or is this the given pspice model with no changes?

3

Hi,

Thanks for your reply

Regarding, Pspice model: We didn’t made any changes in the model. We directly downloaded from Monolithic power website and opened the .dsn file and simulated and then we got the error.

Thanks
Viswa

4

Hi Viswa,
Thank you for pointing out this issue. I will tell our simulation team to take a look and fix the model on the website.

5

Hi Cecilia,

Can you please confirm whether the Pspice model is fixed?

Thanks
Viswa

6

Hi Viswa,

Our simulation team responded that they do not have an issue with the file online. Can you please tell us some details such as the pspice version you have and other error screen shots you may have?