DRV8711 Holding current

Hi Senthil,

1. While using DRV8711 in micro step mode, how does the stepper motor holding happens?

When holding at a step, the amount of current provided is defined by the step table (both direction and percent of full scale current).

As the DRV8711progress through the step table, current is provided in each coil per the table. For example, running 1/8 step and stopping at step 10 will result in 38% of the full scale current flowing in the negative direction in the A coil, and 92% of the full scale current flowing in the negative direction in the B coil.

2.  If the motor is turned-off at 2amps and holding current required is 3amps or 1amps. How to configure the holding current value?

I am not exactly sure what you mean here. Can you clarify?

The holding current is set by the chopping current  and the step table, and modified by the TORQUE register. Please note the Ichop equation on page 11 of the datasheet.

When holding, some applications will reduce the TORQUE value during this time. The result is to have the same ratio of currents in the coils but the absolute values are reduced. This can reduce the power used during holding.

3. Whether DRV8711 can be interfaced to DRV8432?

The DRV8711 predriver outputs will damage the DRV8432 inputs. Please refer to post http://e2e.ti.com/support/applications/motor_drivers/f/38/p/320645/1115806.aspx#1115806 for details.

Hello from Argentina!.
I have a question about the BOOST-DRV8711 , when study the schematics i note that the Rsense is 0.05ohm in series with each motor winding, so in the datasheet of DRV7711 we have 

ICHOP = 2.75V * TORQUE / 256 * ISGAIN * Rsense , if ISGAIN=5 and TORQUE=255 the total chopper current was 10.95AMP so why the BOOST-DRV8711 is rated for 4.5AMP peak only??.

Thanks!

Hi Victoria,

I split your post into a separate thread. You can find the answer there.

http://e2e.ti.com/support/applications/motor_drivers/f/38/t/367760.aspx