LeafLabs Garden

A place to share, learn, and grow...

1. 

   robodude666
   Member

   So...

   I was using the Vin pin for a project and had four AA batteries (6.33V) pack connected to it. It worked well, except for when I accidentally reversed polarity for a couple seconds. The primary regulator (VCC) now outputs 2.454V, while the analog reference regulator (VDDA) still outputs 3.32V. The maple still appears to power up and function -- even the USB bootloader still works.

   Looking at the board, I see four SOT23 packages. The two next to the row of resistors by the USB connector appear to be Q3 and Q2 for the USB DM/DP circuitry. That leaves the other two, by the capacitors and the DC jack, to be the two regulators. However, the only markings are "HU95" and the schematic doesn't label a part number. Is there a known similar part that I could use to replace the regulators?

   I might just get an RET6 to complete my collection.. Until then, I'll play with the Maple Native Beta and my Maple Mini.

   -robodude666

   Posted 4 years ago #
2. 

   poslathian
   LeafLabs

   It sounds like your analog regulator is still working. You could always pop off the digital one, and wire vdda to vcc. As long as you arnt drawing too much current this should be OK. The regulators, by the way, are from Microchip, the MCP series. IIRC, its MCP1703.

   Posted 4 years ago #
3. 

   asterix
   Member

   Ok I did the same, and I'm going to have to wait for the mini's to come out of production before I can order more. I'm hoping that swapping out the regulators and capacitors on my rev5 should get me back online, as I have no power from usb or external. Are these components going to be correct?

   http://au.element14.com/microchip/mcp1703t-3302e-cb/v-reg-ldo-250ma-3-3v-sot-23a-3/dp/1439518

   http://au.element14.com/vishay-bc-components/mal215375229e3/capacitor-smd-16v-22uf/dp/1834244

   Posted 3 years ago #
4. 

   nplayle
   Member

   You might not need to swap the capacitors, but it doesn't hurt to have them on hand either.

   The schematic and BOM for the r5 can be found here: https://github.com/leaflabs/maple/tree/master/maple-r5

   According to the BOM, the regulator is the one you chose, but the capacitor is different.
   The BOM capacitor is here: http://search.digikey.com/ca/en/products/EEE-FPC220UAR/PCE4529TR-ND/1700983

   The difference is the one in the BOM has a lower ESR and a higher ripple current. That said, the one you selected is probably okay unless you're using really noisy components.

   Posted 3 years ago #
5. 

   asterix
   Member

   Thanks nplayle! Your time is much appreciated.

   Posted 3 years ago #

RSS feed for this topic

Reply

You must log in to post.