HTCC-AB01: is it safe to attach Output Voltage of Energy Harvester to VDD?

#1

I am a little bit confused when reading about power supply and the HTCC-AB01. Thus my question: is it safe to attach Output Voltage of Energy Harvester (I am using AEM10941 with Powercaps) to VDD? Is it still safe to connect a USB cable at the same time?

Thanks for clarification!

#2

when the source delivers clean 3.3 V

Is it still safe to connect a USB cable at the same time?

Voltage differences can lead to balancing currents here!

#3

hi,

HTCC-AB01has a voltage regulator chip: CE6260. The function is to provide a stable 500mA and 3.3V DC power supply for the development board. When you only supply VDD(Equivalent to this voltage regulator chip does not work), Please ensure that the above stable DC power can be provided to the system.

When you plug in the usb at the same time, it is equivalent to providing an additional parallel DC power supply for the system, which will cause excessive current in the main circuit (long-term operation may cause damage to some components).

#4

Thanks a lot, Jason!
I just use the USB to program the board. If this is still too risky I will need to detach the energy harvester output while attaching USB. Or disable the CE6260 altogether (but then I loose the ability to program the board when the energy harvester cannot supply 3.3V yet). I think the best solution is maybe just to detact the energy harvester while attaching USB.

#5

You are welcome to continue discussing these issues with us

#6

You can add a diode in order to avoid balancing current in the power harvester(or maybe connect it’s enable line to the usb’s VBUS to shut it down when usb is connected)

Alternatively, you can try programming using TX and RX lines (using external usb to uart converter and entering boot loader manually)

#7

Thanks for this valuable input!