Makerverse Motor Driver CE08038 - Default Logic Voltage

[John76682]

The Makerverse Motor Driver CE08038 documentation says that it is 3V3 & 5V0 logic compliant.

However, as there is no VCC input to specify what the logic voltage may be.

What is the default logic voltage on the CE08038 and is it safe to use with a 3V3 logic ItsyBitsy32U4 without the need of a level shifter from 5V0 to 3V3?

[Oliver33]

Hi John,

I’ve taken a look at the datasheet for the IC (a Toshiba TC78H660FTG). You don’t need to hook up a logic reference voltage to it, all it needs is the motor power supply. Any voltage below 0.7v is a logic low. Any voltage above 1.5v (up to 5.5V) is a logic high.

It has an internal voltage regulator, so you can power it on anything from 3V-16V (the IC is actually rated for 2.5V - 16V, but looks like Core have given themselves 0.5V headroom to account for the bit of loss between your input and the chip).

The schematic’s a little confusing because it doesn’t match up with the PCB labels. Instead it uses VCC and VDC instead of VM.

VM on the PCB = VDC on the schematic = whatever external power you supply. VCC is VDC, on the other side of the reverse polarity protection mosfet. On the schematic, VM is only used in one place - the pinout of the IC.

[John76682]

@John76682

CE08038

Thanks Oliver33 for the quick reply.

I probably should have tracked down the datasheet myself - It would be great if Core could provide a link to the chip datasets directly in the “Resources” list, much as Adafruit often do for their products .

I guess when all is said and done we are only writing → the logic pins and 3V3 is sufficient to flag a HIGH.

After you blow up a couple 3V3 pins with 5V0 is hard not to be just a little paranoid .