LM27761: -5V is not getting with +5V input

Namitha K M

Part Number: LM27761
Other Parts Discussed in Thread: TPS63710

Hi,

i'm using LM27761 to generate -5v output from +5v input. But i am not getting the proper output. Below is the schematic. May i know whether i need to change any of the capacitors value or is there any other issue.

Maximum input i can provide here is 5V or 12V. If it is not possible with LM27761 to generate -5V, kindly suggest with the alternate part.

over 3 years ago

0 Febin over 3 years ago

TI__Mastermind 19180 points

Hi Namitha,

You will not be able to generate -5V from 5V Vin, as you also need to account for the losses. So please increase the Vin (around 5.4V or so) to see if you achieve the desired output.

We do not have an alternate device to power a negative rail but we can suggest a buck converter which can be reversed to power the negative rail.

Regards,

Febin

0 Febin over 3 years ago in reply to Febin

TI__Mastermind 19180 points

Hi Namitha,

I have another suggestion for an inverting buck TPS63710 which has a higher Vin range. Looks like this could be a choice for your application. Please have a look at the datasheet.

https://www.ti.com/lit/ds/symlink/tps63710.pdf

Regards,

Febin

0 Namitha K M over 3 years ago in reply to Febin

Prodigy 200 points

Ok thank you for your suggestion.

0 Febin over 3 years ago in reply to Namitha K M

TI__Mastermind 19180 points

Hi Namitha,

If you do not have further questions, I will go ahead and close this thread.

Please hit "Resolved" if I solved your problem.

Regards,

Febin

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LM27761: -5V is not getting with +5V input