High temperature of twl4030


I’ve noticed that when I connect usb hub to beagleboard the temperature of power ic ( twl4030 ) increases to danger level. Hub is powered from its own power adaptor but it can take current through the usb cabel from beagle or PC. I assume that if vcc line will be disconnected from hub than only power adaptor will suply hub… and yes, it was good idea but only for PC. Beagle dosn’t see hub without vcc line. I’m using usb adaptor mini-A plug to A receptacle. In usb receptacle on beagle I close 4th and 5th pin to get host usb mode.
Did I miss something? High temperature is a normal state (?). Beagle will not work with usb hub wihtout vcc line (?).


What HUB are you using? If the DC into the HUB is or’d with the power from the TWL4030, that is not a good scenario. The HUB should break this connection and use the DC only from the external supply. The TWL4030 can get a little warm. The term “Danger Level” is a subjective term and has no real value. Is there any chance you can measure the temperature of the TWL4030? What is the current consumption of the Beagle from its DC supply when in this configuration?


I know that it’s subjective and depends on IC model / type. I was taught that if very small drop of water vaporize quite fast from the top of ic, here less than 5s, it’s not good.
I’m using low end usb hub. It’s based on GL850A chip. Unfortunately Vcc from power adaptor and from USB cable are connected without any isolation. Beagle gives about 300mV less than power adaptor of hub, that is the reason of overheating. Confusing is fact that if I disconnect Vcc in usb cable beagle doesn’t see hub. If gnd is disconnected beagle see hub, but wifi drivers are going crazy when wlan interface is up. Now I don’t have a proper multimeter to measure current and temperature but I will do it asap.

fast fix: resistor 560ohm on vcc line of usb cable and everything works fine

Interesting. Let me think on this a while and see if I can figure out what is going on.