Tic T834 Getting Very Hot

Using a TIC T834 and tied the VIN to 5V from USB and GND from USB. Using a low current motor (200mA) and everything drives fine. However, the inductor close to the VIN and GND inputs is getting dangerously hot (>>70C, maybe more).

Is this normal?

I do not notice this behavior when using an external power supply. I would really like to use the on-board USB power since it works for my device. Why would using on-board USB Gnd/+5V cause the inductor to get so hot?

It sounds like you are trying to power the VIN pin on the Tic from the 5V (out) pin. That really is not an intended use for the 5V (out) pin. When VIN is powered, the power switching circuit uses it to power the 5V (out) pin through an onboard regulator instead of sourcing it from USB. You are probably creating a feedback loop where the regulator is effectively trying to draw increasing amounts of current from itself.

If you really want to power the motor from the USB power, you could draw it from the VBUS test point (indicated below) instead:


This worked perfectly! Thank you!

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