UCD9244/UCD7242 adds noise at input supply

HI ,I use one UCD9244 and two UCD7242 to supply four C6678 DSPs, however ,i do not know how to configure the UCD9244，I do not know how to configure the correct "XML"  File,there are always some errors. I find our designs are similar. Could you please send your configured "XML" File to me as a  reference?  Thank you in advance.

Please post your contact so i can reply

OK,Firstly ,Thank you for your reply ~ I am a graduate student in XI AN City of China. My email is hugongsheng@126.com   I will be very happy to recieve your email. Thank you for your help.

HI，Mr Hu i am sorry to bother you again. I have used your design file to configure my UCD9244. There is no errors,however there is no voltage output. I have chosen "the always converting" option.,because i think these is no enable pins on the UCD9244. The attached picture is the screenshot of that software. Have you ever met the problem or can you give me some suggestions?I have been troubled by this problem for many days. Thank you in advance~ 

Mine works.

UCD9244 does have enable pin: Pin 28 - PMBUSCTL. But if you select "always converting" it should work. Make sure you configure this for all 4 channels.

You may have to change the design file because yours and mines may not have same outputs.

My output 1 is 1.0V, output 2 is 1.0V. Both have VID control.

Output 3 is 1.0V, fixed. Output 4 is 1.5V, for this output, there is resistor divider for feedback which is set to VOUT_SCALE = 0.5.

hi Chao Hu:

      Would you like to tell me how you solve the problem of  UCD9244 adding noise to input supply.

      I have met the same problem.

      thanks very much.

I still have the problem. Since the noise is at input side, the problem is not severe enough to cause trouble. My circuit works.

I did talk to TI, their suggestion was make sure you use low ESR (like ceramic) caps for decoupling.

thanks very much!

your UCD9244 switching at what frequence.

750kHz