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ESP-12 Adapter Board - underside Voltage Regulator size?

PostPosted: Sat May 07, 2016 3:14 am
by bgowland
I've just bought some adapter boards for some ESP-12 modules - the underside looks similar to the attached image.

As far as I can tell, the little pads are for a 3.3V surface mount voltage regulator but I'm not sure about the package style/size I need. After searching, it looks like SOT-89 might be it but I'd appreciate the confirmation.

Also, from various sites that sell these boards, they say the voltage regulator pads are "jumpered", i.e., direct connection for 3.3V supply at the edge connector when not using a voltage regulator. I can confirm the Vcc edge connector pin has a direct connection to the ESP-12 Vcc pad. What do I need to do if I put a voltage regulator on there? I'm guessing I need to remove the 0R resistor (dead short) which seems to be acting as the "jumper" link. Am I correct?

Cheers,
Brian

Re: ESP-12 Adapter Board - underside Voltage Regulator size?

PostPosted: Sat May 07, 2016 11:03 am
by dnc40085
SOT-89 is correct. I used a HT7333 regulator on mine.

Make sure you remove the jumper, I forgot to and fried 1 of my esp-12e modules.

Re: ESP-12 Adapter Board - underside Voltage Regulator size?

PostPosted: Sat May 07, 2016 11:24 am
by lethe
XC6203 works as well.
The pinout for SOT-89 regulators seems to be standardized, but you may want to double check if it matches before buying...

The only issue is, that there are no pads to mount caps on the 3V3 side. I used the via next to GPIO13 to mount a tantalum bead capacitor on one of my boards, but a some proper pads for a capacitor would have been nice...

Re: ESP-12 Adapter Board - underside Voltage Regulator size?

PostPosted: Sat May 07, 2016 9:11 pm
by bgowland
dnc40085 wrote:SOT-89 is correct. I used a HT7333 regulator on mine.
Thanks for the confirmation and suggestion of regulator type.

dnc40085 wrote:Make sure you remove the jumper, I forgot to and fried 1 of my esp-12e modules.
Ouch - I'll make sure I don't forget that.

Cheers,
Brian