Design of Telecom power supply -48Vdc

Please clarify my query. It is little urgent and I need to process the transformer design for production.

regards,

mahesh

Hi Mamesh,

Thank you for using Power Integrations' part.

Regarding your question, that is actually how it works connecting the 48V load to RTN(0V) of the power supply then 0V of the load to the 48V of the power supply to have -48V input to your load.  Have the feedback connected to your 48V output if you want to have better regulation for your 48V.  Thanks.

Many thanks for your reply.

I didn't get your last sentence!!!,

"Have the feedback connected to your 48V output if you want to have better regulation for your 48V". 

-48Vdc would be the input to the power supply with multiple DC outputs such as 5Vdc, ± 12Vdc.

Do you have any reference design circuit which shows the feedback connection??? or you can just scribble on the schematic that I have sent and resend??

Thanks for the wonderful support from PI.

regards,

Hi Mamesh,

What I mean is from the same schematic that you have, convert the 5V output to 48V so that your feedback is on the 48V output for better regulation of your -48V output.  However if you are not much concern with the regulation of your -48V, you can just convert the -12V output to -48V with the feedback loop at your 5V output.

Hello,

I am not getting why i should convert the 5V output to 48V.

Please note that the input to this power supply (DC-DC converter ) would be typically -48Vdc, from a battery, but I have designed for the range 36V to 72Vdc. 

Referring to the design which i have sent earlier, i require 5Vdc, +12V and -12V output which goes to my other circuitry.

Hope I have made clear about my requirement.  I have already got the transformer details for my requirement and the schematic i have sent to you.

regards,

mahesh

Hi mamesh,

Sorry for confusion.  I thought you are designing a power supply that needs -48V output that is usually used in telecoms.  Again sorry for that.  

Yes your idea is correct how you connect the input of the DC-DC power supply from the battery.  Your design is good to go for your multiple output requirement.  Thanks you.

Thank you for the support.:-)

regards,

mahesh