DRV8711 doesn`t start

Hi Pavlin,

Please disconnect the motor, power the board and check the following:
SLEEPn is a logic high and RESET is a logic low
All faults are cleared
ENBL bit is set to a 1

At this point the AOUT1 and BOUT1 outputs should be at VM and the AOUT2 and BOUT2 outputs should be at ground. This indicates the device is operational.

Once device operation is confirmed, the step input will cause the outputs to reverse per the indexer table.
The motor can now be reconnected. The motor may require an acceleration profile to achieve the desired speed.

Hi! Sleepn is in logic high(5V), Reset-> logic low. All faults cleared, ENBL=1.
In this case I don`t have VM on any OUT pin! Is there anything else?
Thanks!

Hi Pavlin,

There are a few more items to check.

Please check and report the voltages on V5, VINT, and VCP before and after the previously described steps.

Also, if you have a pullup on the FAULTn pin, please report its voltage.

After the described steps, it is expected to find

V5 = ~5V

VINT = ~1.8V

VCP = ~VM + 10V

FAULTn = ~pullup voltage (logic high)

Would you please repost the schematic by selecting "Use rich formatting" to the bottom right of the reply window. Once selected, click the "Insert File" icon and add the schematic. The link is not viewable due to site restrictions.

Hi! It seems I have a problem.

I have only 1.3V on V5, 0.3 on Vint and 12V on VCP.

My control pins are Sleep -> 5V(high), Reset 0V(low).

Any suggestions?

Thanks!

DRV8711 schematic.pdf

Do I have to connect BIN1 and BIN2 directly to GND or I have to leave them unconnected?

Hi Pavlin,

It appears like the device has either been damaged or there is some type of connection problem to the board. If you have a second board, please try it for confirmation.

The R1 and R3 values appear to be incorrect. It is possible this could have damaged the device. 1mA through R1/R3 violates the absolute maximum voltage on the xISENP pins. Typically, R1 and R3 are less than 1 Ohm. Please address this prior to the next time the device is powered up.
What is the recommended motor current?

If you have a second board or replace the device, please check for solder bridges and pin to pin shorts prior to power up. Once powered up, raise SLEEPn and measure the VINT and V5 and VCP voltages. If good, then proceed to SPI writes to enable the outputs.

BIN1 and BIN2 can be left unconnected. There an internal pulldown resistors.

I`m sorry R1=R3=0.22ohms. I`ve missed that!
I have another board! I`ll solder it and try again!
But this time I`ll leave BIN1 and BIN2 unconnected (not connected to GND as in present case).