Powering Tiva-C launchpad via USB Charger

[milankarak 0]

Hi all,

 

I am quite new with launchpads so maybe silly question: Is it possible to power launchpad using USB charger?

I was expecting the answer to be yes, but after I tried it my launchpad stopped working after some time.

 

It looks like voltage regulator U8 (TPS73633DRBT) is broken since 3.3V port is giving >4 V.

 

I understand that wall USB chargers produce higher current but not sure if this is the reason. I actually used cheap Chinese charger (I know...) which as I realized later is not really giving stable Voltage (I measured as low numbers as 2.9 V). Could this rather be the reason? Can I use correctly working charger safely with my new launchpad?

 

Any idea how to fix the old one?

 

Thanks!

[dubnet 238]

First of all, welcome to the forum.

 

Secondly, sorry to hear about your mishap.  You didn't mention which Launchpad you were working with so I couldn't check the voltage limits for the CPU involved but anything north of 4V doesn't bode well for the CPU on your Launchpad.

 

Higher currents on the USB input side won't hurt you but out of spec voltages and large amounts of ripple from a substandard power supply probably will.  I have used USB chargers to power a variety of Launchpads without any problems. But these were higher quality OEM units from cell phones and tablets.

 

You could try replacing the regulator but if the CPU was damaged by the overvoltage then you will need a new Launchpad.

[milankarak 0]

Thanks a lot. It makes perfect sense.

 

Btw, it's Tiva C Launchpad so Cortex M4 CPU.

[abecedarian 330]

@ If you are in the USA, send me a message with your address and I'll send you a new TM4C123G LaunchPad.

[milankarak 0]

@@abecedarian thanks a lot for the offer. Unfortunately I am in Europe.. Anyway, I already have a new LaunchPad to play with :-)