How to change Vout on AM-1885 LM22670

Arya Banait

Other Parts Discussed in Thread: LM22670

Hi,

I am trying to use the AM-1885 LM22670 Evaluation Board for a switching application and need to switch from 12V down to 5V. This regulator has a preset Vout of 3.3V and the datasheet says that Vout is adjustable; however, I was unable to find any mention of how to change this value of Vout other than modifying R1 and R2 on the schematic (or may be increasing input current, but I am uncertain about that). Changing R1 and R2 would require ordering or making a custom board. Is there another way to change Vout for this board?

Thank you and regards,

Arya Banait

over 8 years ago

0 Mladen Koren over 8 years ago

Prodigy 210 points

Hi,

You need to change R2 with 2.8kΩ 1% (e.g. CRCW06032K80FKEA) and you will get on Vout=4.97V.

Regards,

Mladen

0 Arya Banait over 8 years ago in reply to Mladen Koren

Prodigy 30 points

Hi,

Thank you for your response! I am aware that I will have to change the resistance. My question is how do I do it? Do I need to order a custom board from TI with my desired R2 value like you said (2.8k) or is there a way to change the resistance on the board itself?

Thank you and regards,

Arya

0 Akshay Mehta over 8 years ago in reply to Arya Banait

TI__Genius 15810 points

Hello, I am not sure if there is a different eval board with 5Vout option. If you have access to a lab and some components, you could remove the resistor R2 and replace it with the desired value of 2.8kohms.

0 Arya Banait over 8 years ago in reply to Akshay Mehta

Prodigy 30 points

I will try that out. Thank you!

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How to change Vout on AM-1885 LM22670