Powering TM4C1294 Connected LaunchPad from Boosterpacks

According to p. 22 of The TM4C1294 User's Guide

"JP1 is provided to select the power input source for the Connected LaunchPad. The top position is for BoosterPack power; this position also disconnects both USB voltages from the board’s primary 5-volt input. In the top position, the TPS2052B does not limit current so additional care should be exercised."

So perhaps you've gone overcurrent?

Here's the datasheet for the TPS73733-DRV (Although, note that the DRV is a WSON package, and in the "Pin Functions" table, WSON and VSON are switched.)

Thank you, so it seems connecting the power to the 5V pin is the way to go, but I need to be careful with currents.
But I am still a little curious: can overcurrent damage the bypassed TPS2052B and leave both the TPS73733 and the TM4C124 still working?

Hello Huy

What was the current capacity of the 5V regulated source set to? Normally it is meant for the Battery Booster Pack which has current limited output on 5V.

Regards
Amit

Hi Amit, thank you for replying

I used a 5V-fixed version of the AMS1117, which supposedly has a maximum output current of 800mA. Is it still safe for the launchpad? Also I used a power source from the university lab as input for the AMS1117 boosterpack, from the indication on the power source, at 12V the current hardly ever goes past 300mA, but I guess it will get higher at 5V after regulation.

Thank you, Amit.
I should have paid attention to overcurrent protection, luckily I did not break the TM4C124.

But with my rather limited knowledge, I find it strange that the damaged part was the TPS2052B  (whose input was bypassed by the jumper connection) and not the TPS73733  or the microcontroller itself. Can you please enlighten me about this?
Also, can I order a TPS2052B from TI so that I can replace the fried chip?

PS: I am sorry I mixed up the two ICs, I just edited my post to reflect the right name.

Hello Huy,

Yes, it is strange that TPS73733 is damaged. When you removed it did the removal happen on a system that was powered?

Regards
Amit

Hi Amit,
I don't remember whether I turned the power source off before removing the boosterpack from the launchpad, so that could have been the source of the problem.
I noticed that a sample TPS2052B of the right package can be requested from TI, so I will try to fix it once the request is approved.
Thank you for your help, I really appreciated it.

Regards,
Huy

Hello Huy,

I though you said TPS73733 was damaged.

Regards
Amit

I am sorry, I meant tps2052, but I mixed the two up in my previoud post.
From what I know, setting JP1 to Boosterpack will leave out the current limiter tps2052 and feed the 5V from the boosterpack to the tps73733 LDO, so the external source could not have damaged the tps2052, and tps73733 should be the one more likely to die. But again my knowledge and experience is very limited and I hope to be helped with this :)

Hello Huy

I don't think that is the case. The TPS2052 is for Target USB Current control. However removing the 5V when the supply was live may have damaged the TPS73733.

Regards
Amit

Hi Amit,
When I try connecting an external 5V source to the 5V pin which is connected to the input of the tps73733, I still get 3.3V on the output and the microcontroller works. I thought that is a sign that the tps73733 is still working.
Is there a method that I can use to determine which one of them is broken?
Thank you so much

Hello Huy,

That is correct. In this case it is the TPS2052 that may have been damaged. When you apply 5V on the input of the TPS5052, what is that you measure on the input of the TPS73733?

Regards
Amit

Hi Amit,

Powering the board from USB, I got a 3.1V reading on the 5V header pin, which I assume is the same as the input of the TPS73733, the output of the TPS73733 would then be 3.0V.

The launchpad is operational, albeit unable to program without an external 5V being applied straight to the input of the TPS73733.

Hello Huy,

It may be because the TPS0262 is broken or faulty. I would go by replacing it first

Regards
Amit

Hi Amit,
I have already ordered a sample TPS2052 from TI.

I am really glad that you helped me, thankyou so much.

Huy

Hello Huy,

Please be sure to post back the results on the forum. It could be useful to others.

Regards
Amit

Hi Amit,

I received my requested packet of 5 TPS2052s today, and managed to solder one of them onto the launchpad.

The launchpad is now working properly. I hope this could be helpful to other users who encounter similar problems.

Thank you for your support.

Regards

Huy Dinh

Hello Huy,

Indeed it would be. It should always and also be a strong consideration, when designing a system to limit a source so that it does not violate any device rating.

Regards
Amit