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XC6206P332MR 662K 3.3V 200mA TOREX LDO Voltage Regulator SMD SOT-23

The capacitors on Vin and Vout are not too close, maybe 1cm away from the pins, I've tried anything from 0.1uF to 22uf, Im powering the LDO from a 4.2 Lipo, It's the second LDO from a second supplier I'm trying.

Considering my input is DC, I'm a little confused why it's overheating. It appears to be drawing 200ma. Behaves the same with no load or if I connect a 1k resistor for some load.

I haven't tried an oscilloscope yet though to see if there's some instability. It is my first SMD circuit, I've used non SMT 3.3v regulators before without any issues.

Ordered and soldered two new 1uf ceramic capacitors as advised, did not change the outcome however. my caps could definitely be placed a lot better.

enter image description here

enter image description here

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    \$\begingroup\$ 1) include a schematic (yes even though it will be an obvious one). 2) are you 100% sure you're connecting it correctly ? Remeasure (continuity check with multimeter on unpowered board) anyway. 3) are you using ceramic 1uF caps as indicated in the XC6206 datasheet ? \$\endgroup\$
    – Bimpelrekkie
    Commented Sep 12, 2017 at 12:33
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    \$\begingroup\$ 4) if you must answer 2) or 3) with no then the LDOs might be damaged already. It is always better to check PCBs when powered from a lab supply with current limiting at 50 mA or so. A charged LiPo cell can destroy any IC in a fraction of a micro second when connected in the wrong way (like reversed supply). Oops ! \$\endgroup\$
    – Bimpelrekkie
    Commented Sep 12, 2017 at 12:39
  • \$\begingroup\$ I seem to be using Tanatalum capacitors... Descriptions of similar problems talked of importance of the capacitors, but also of high frequencies etc, but I figured this is DC so not so crucial..I guess I need to buy some ceramics and try with a fresh LDO? Ive checked the wiring many times, it doesnt seem to be the probem. \$\endgroup\$
    – Krzysztof Stankiewicz
    Commented Sep 12, 2017 at 12:41
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    \$\begingroup\$ @KrzysztofStankiewicz - I recommend you edit your question to add a close-up, in-focus photo of your circuit board, showing the regulator and surrounding components (capacitors etc.) and wiring. That will help readers to identify capacitor types and other relevant details. \$\endgroup\$
    – SamGibson ♦
    Commented Sep 12, 2017 at 12:51
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    \$\begingroup\$ The picture says LM1117, the schematic says LM3480 and your post says XR6206. All of them have incompatible pinouts, so my guess is that this is simply a pinout error and the chip you soldered is now burned... \$\endgroup\$
    – bobflux
    Commented Nov 1, 2017 at 9:54

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Like @peufeu states, it is not clear what voltage regulator you really were planning to use, but if we should go by the schematics, it is the LM3480, and that is what the layout is suggesting (as far as I can see from the potato vision image attached) I can tell you right away, that if you as you state in the question - were trying to mount a XC6206 on the footprint for U4 from your picture, it will of course not work as expected. Have you even read the datasheets for the parts you use? The physical pinouts are literally on the first pages of the datasheets.

This is essentially what you have connected:

schematic

simulate this circuit – Schematic created using CircuitLab

This is the block diagram for the XC6206 (Taken from the Datasheet: enter image description here

I don't think I will have to tell you why this is heating up, do I?

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    \$\begingroup\$ Thanks for taking the time to write the answer! Gotta solder the chip upside down or sideways to fix this... \$\endgroup\$
    – bobflux
    Commented Nov 1, 2017 at 16:24
  • \$\begingroup\$ I didn't notice the XC6206 has a different pinout. Thank you for pointing that out. Initially I was using the lm3480 and the pintout seems to agree with my schematic. I had trouble with the lm3480 as stated in the initial question, so i went onto the xc6206 because i did not trust the supplier and i thought the lm3480 should have just worked, so i thought perhaps they sent me the wrong part. i just tried a fresh lm3480 on the pcb again and it seems to be overheating as before. i will reorder it i think, not xc6206 but another lm3480 as per my initial design. \$\endgroup\$
    – Krzysztof Stankiewicz
    Commented Nov 1, 2017 at 23:01

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