Loss of Regulation when connecting a Load (Viper06X) URGENT !

ahmed239955_st · ‎2016-08-31

Posted on August 31, 2016 at 22:43

I have created a new post because I cannot reply on the first one due to functionality of your website.

The problem again :

I have used

Viper06X (30KHz) as a buck to get 9V output

, with no load I have the right output voltage. But

when I connect any load (even it is light) the output voltage drops

.

As the load resistance decreases the output voltage decreases !!

It reached 7.8VDC with only 90mA load !!

And it reaches 2.5VDC when the output current tries to reach 150mA !!!

/analogsimulator/flex_app/bin/smps_app_acdc_design.html?msg=%7b%22data%22%3a%7b%22application%22%3a%22acdc%22%2c%22specs%22%3a%7b%22input%22%3a%7b%22v%22%3a%7b%22min%22%3a110%2c%22max%22%3a235%7d%2c%22f%22%3a50%7d%2c%22ic%22%3a%22VIPER06XS%3abuck%22%2c%22output%22%3a%5b%7b%22v%22%3a9%2c%22i%22%3a0.33%2c%22r%22%3a2%7d%5d%7d%7d%2c%22action%22%3a%22new_design%22%7d

#viper06x

Patrizia BELLITTO · ‎2016-09-04

Posted on September 05, 2016 at 08:58

Please, could you send some wave forms about the current and the output voltage trend?

Otherwise it's impossible to understand which is the problem.

ahmed239955_st · ‎2016-09-08

Posted on September 09, 2016 at 00:15

Ø£Here is a link

http://imgur.com/a/HoftP

Nickname6829_O · ‎2016-09-08

Posted on September 09, 2016 at 08:32

Hello Ahmed,

please could you send an archive of the OrCAD project you are simulating?

Best Regards,

Carmelo

ahmed239955_st · ‎2016-09-21

Posted on September 21, 2016 at 14:12

here is a link

https://drive.google.com/open?id=0BydjomGbJ22Namw5eUt5YjJOWjA

Nickname6829_O · ‎2016-09-22

Posted on September 22, 2016 at 14:18

Hello,

the application you sent me is not correct. For example it contains a very small output capacitance (C4=1nF) and the resistor R2 is not connected well.

Please find attached a solution designed with eDesign Studio ready to be simulated.

Best Regards,

Carmelo

________________

Attachments :

VIPER06.zip : https://st--c.eu10.content.force.com/sfc/dist/version/download/?oid=00Db0000000YtG6&ids=0680X000006HzEO&d=%2Fa%2F0X0000000bIf%2FQSBoSaBYl8uIae1wlVHtt4ILJYXMwNXKO27Nb_VjMZE&asPdf=false

ahmed239955_st · ‎2016-09-24

Posted on September 24, 2016 at 12:58

Thanks C

armelo,

Yes you are right I have problem with the files .

Seems also that I have a problem in my OrCad A/D simulation, if you can send me a screenshot of sweep analysis I will be thankful.

Nickname6829_O · ‎2016-09-25

Posted on September 26, 2016 at 07:57

Hello,

can you please provide me further details about the simulation you would like to run? The kind of sweep analysis, the simulation settings, the waveforms you want to analyze.

Best Regards

Carmelo

ahmed239955_st · ‎2016-09-27

Posted on September 27, 2016 at 19:50

I just want the output voltage variation with varying the load resistance , so it is only the VI curve needed .

Thanks Carmelo for your friendly support .