Merde with SMPS

Douglas Beeson · 2014-11-10T14:54:10+00:00

Hi all, So I decided to leap with both feet into the deep cold pool of switched-mode power supplies, surface-mount no less, and now have something that doesn't work as advertised. I could use some help debugging it. I am trying to get 5V out with two AA cells as input. My IC of choice is the TI TLV61220. Here is the schematic: and here is the board layout: The full board has two more SMPS ICs that do 5->15V and 15->-15V conversion, but I have unsoldered those to better isolate the problem with the 3-5V circuit. I am getting about 2.7 V out, which is up from 1.8 V when the other two SMPS ICs were in place. I could provide some images from the oscilloscope. What would be useful? Thanks! -- Douglas Beeson

Nov 10, 2014 21 Replies

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Douglas Beeson 11 years ago

No, this was my error. I accidently trashed the files that were in Dropbox. Here they are again (I just tested it).

Schematic:

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Board:

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Vout :

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Feedback Pin (should be 500mV, not 350 mV):

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Thanks, Jasen

Clever.

Douglas Beeson

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Jasen Betts 11 years ago

still 404

umop apisdn

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