We are building a device which has good amount of MP2229 supplies already for 5V and 3.3V supplies. There is now need to generate 12V output also and I was thinking of using MP2229 to reduce component count from BOM.
The input voltage for 12V regulator will be 19V and output should be capable of 2A. I used MPS DCDC Designer tool to calculate component values but I became suspicious that will it work for 12V as there is no mentioning of voltages above 5V in the datasheet. Could you double check the values chosen in the designer if it will work for 12V/2A output or is there some limitation in the chip that it won’t work for higher voltages?
Based on the calculated specs it should be ok but could you double check and verify?
Hi jaakko.isohella,
To regulate a 12V output with the MP2229 from a 19V input, the max duty cycle will need to be ~63% (Dmax = 12V/19V):
Looking at the EC table on Pg. 4, this part can handle a Dmax up to 95%, so it seems like the MP2229 should handle this application just as long as the duty is high enough. Additionally, the max current limit in the EC table is 10.5A under the condition D = 40%, but it’s only a 2A application so this shouldn’t be a problem.
I also received the bode plot for your system:
I would like to refer you to this page on our website that talks a little bit more on how to diagnose and fix an unstable system. In terms of what you are trying to achieve, the bode plot does look normal and is representative of a stable system. The “notch” you see should be expected but the phase (and gain) margin and response are well within the limits you’d want to keep your system stable. I would recommend paying attention to the other plots the designer provides, but I see nothing wrong with your system as is.