WEBENCH® Tools/LMR33630: LMR33630 Design

Pedro Silva17

Prodigy 30 points

Part Number: LMR33630
Other Parts Discussed in Thread: LM3481

Tool/software: WEBENCH® Design Tools

Hello

I used the WEBENCH to help me in the design of a power supplu for the uBlox-Sara-U200 cellular module (picture above).

The ideia is to power supply the board, between 4.5 and 30V with an output of 3.3V @ 2.5A (maximum).

I intend to use the same model, but this time, to have an output of 5V @ 2A (maximum), with the same voltage input from 4.5 to 30V. The WEBENCH design didn't show-me this model for this voltage ouput. However, in the datasheet of the LMR33630. says that I can have an output of 5V. It presents the second desing that i post here. Is there anyway of using the same model as the first one? Or because the voltage from input is too close to the voltage of the ouput that is not recomended.

Best regards

Pedro

over 6 years ago

0 Samuel Jaffe over 6 years ago

TI__Mastermind 25590 points

Pedro,

LMR33630 is a buck converter. A buck can only output a voltage lower than the input voltage. So VIN=4.5V cannot get you VOUT=5V.

You can use a buck-boost or a fly-buck for the 4.5VIN --> 5VOUT supply.

-Sam

0 Pedro Silva17 over 6 years ago in reply to Samuel Jaffe

Prodigy 30 points

Dear Sam,
Thank you for your help. I though about that... I am thinking about using the LM3481 where the efficiency is arround 80-85%. Do you know if there is another alternative better? My ideia is to use a 2 layer PCB to keep it low cost...
Regards
Pedro

0 Samuel Jaffe over 6 years ago in reply to Pedro Silva17

TI__Mastermind 25590 points

Low cost option would be to go with the LM3481. You can use WEBENCH to optimize for efficiency, cost, size... You can use those options to come up with a solution that is optimized for your budget/specs.

-Sam

0 Pedro Silva17 over 6 years ago in reply to Samuel Jaffe

Prodigy 30 points

Thank you
Regards
Pedro

Power management

Power management forum

WEBENCH® Tools/LMR33630: LMR33630 Design