how to generate negative 9v

[Dhaval Shah]

hi all

i am trying to generate negative 9v from positive 12v using lm358 op amp..but its not working..

any help..please give me suggestion if any one knows how to get it..its urgent



thanks

 

[keith1200rs]

You need to give more details. If you have a single 12V supply and want a -9V supply then you need a switching regulator chip. Go to **broken link removed** and type your requirements in to Webench and it will suggest some chips to do the job. Or you could buy a DC-DC converter.

Keith.

 

[Dhaval Shah]

thanks for the reply..

i am using single supply of +12v and want to generate +15v and -9v using lm358...in this case i got +15v and its work but i didnt get -9v...any suggestion

 

[keith1200rs]

What circuit have you used to generate 15V from 12V with the LM358? How much current do you need from the 15V & -9V?

Keith