So I've bought a TB6612FNG motor driver module and had it tested under USB power using a Nano clone. What surprised me is that the motor that is driven by it ran as what I should expect from the code, even though it is only powered by USB.
Now I tried to check for voltage across the Vin, since when i disconnect the Vm pin of the driver from the Vin pin of the Nano, it stops. I got a reading of 4.3V. The Nano clone btw has a AMS1117-5.0 LDO regulator and a CH340G USB to serial chip.
Can someone help me understand why it happened? Was it because of the nature of the LDO regulator? Thanks in advance for your help
You mean the Schottky diode? There's a Schottky diode on it, though I've read that this prevents the higher Vin from getting into the Vusb... Ill try to check if it is still functional
ExcitePrime:
You mean the Schottky diode? There's a Schottky diode on it, though I've read that this prevents the higher Vin from getting into the Vusb... Ill try to check if it is still functional
Let me correct myself: instead of "higher Vin", it should be "external 5V"
There is an internal diode in the regulator, so vin is backpowered through the regulator from.the 5v rail. That schottky diode is between USB power and vcc, so it doesn't prevent this.
I dont think the continuous current max through that internal diode is spec'ed, so it is not advisable to use it this way.
