Output Spike in TOP268KG

Posted by: viki_csk on 07/09/2015

Hi everyone....

i have a spike in output waveform...componenet are same as PI Expert software specified...

I tried to change post LC and Y class capacitor to remove this spike but it remains same...

loading the smps incease the spike levels...

I attched the waveform of output and design file....

Files

Output Waveform (79.93 KB)

Design File (707.5 KB)

Comments

Hi, for which output voltage you are seeing the Spike. How much is it the Peak to peak? The waveform that you sent was unclear. Could you please resend it again?

Regards,

PI-KSAN

Hi....

both outputs have a spike with same peak to peak voltage about 3V.i attached waveforms.

I place the component as per PI expert design results but i got output 16V instead of 12V and 8V instead of 5V

after changing R12 = 6.19K to 4.7K,R14=53.6K to 47K and R16=215K to 133K only i got 12V and 5V.

Thanks &regards,

Vignesh

Attachment	Size
TEK0012.JPG (179.11 KB)	179.11 KB
TEK0013.JPG (180.42 KB)	180.42 KB
TEK0014.JPG (178.83 KB)	178.83 KB

Hi Vignesh,

How are measuring the ripple? In the PI Expert design that you sent to us , i see two output voltages one is 42 V and the other is 5V output?

Please go through how to measure the ripple measurments in the below reference design, Page No:38

http://ac-dc.power.com/sites/default/files/PDFFiles/rdr462.pdf

Regards,

PI-KSAN

we got a same problem using 4987A BNC Adapter from probe master also.

please provide a solution as early as possible.

Could you please send us the picture of your Oscilloscope probe how you are measuring the ripple?Did you followed the procedure as recommend in our reference designs.