hello TI:
i found a problem of the DRV8811,i use a FPGA to control DRV8811,i use S-curve accelerate,the max speed is 28khz (Eight microsteps),then the motor's speed from 0,accelerate to 28khz, then run at 28khz ,when motor reach the Optocoupler ,i get the stop signal,then i immediately turn off the speed,the speed from 28khz become 0hz,then DRV8811 die,it is probability ,not every time ,i must reset the IC or turn off then then on.at first i think the problem is my hardware design,so i use the DRV8811 EVMbord,take the MPS430 out,use my FPGA to control,same phenomenon.
my VM=26V, the other is the same,like the DRV8811 EVMbord,my current is set 2A,decay =3.3V,SRn=0,my board don't have 8 diodes,but your DRV8811 EVMbord have ,It doesn't matter.
can you tell me why? i found some guys have Had the same problem,in other forum
i konw, this is because of the ocp (Overcurrent Protection.),but i don't know how it happen?,and how to do
this is from your datasheet
If the current through any FET exceeds the preset overcurrent threshold, all FETs in the H-bridge will be disabled
until the ENABLEn pin has been brought inactive high and then back low, or power is removed and re-applied.
Overcurrent conditions are sensed in both directions; i.e., a short to ground, supply, or across the motor winding
will all result in an overcurrent shutdown.
Note that overcurrent protection does not use the current sense circuitry used for PWM current control and is
independent of the Isense resistor value or VREF voltage.