Texas Instruments DRV8825 microstep sine wave output current waveform captured with a oscilloscope using a current probe. These current waveforms are similar to Figure 8 in the datasheet.
DRV8825 is a 45volt, 2.5amp, up to 32 microstep driver
When using a DRV8825, a TL-smoother should be used. It exhibits irregularities while spinning at low rpm. This website helps explain the missing microstep problem.
Measured output current
Step pulse input testing. I set the microstep to 32, the maximum for this driver. Using a HP8116A Pulse generator, the stepper driver was able to handle over 200Khz step pulse rate. Power supply set to 36 volts. The driver works best with 2 microsecond pulse width or higher.
DRV8825 8 microstep 5rpm 12volts. Driver output current set at 500ma RMS.
DRV8825 8 microstep 5rpm 12volts with TL-Smoother. Driver output current set at 500ma RMS.
DRV8825 8 microstep 5rpm 24volts. Driver output current set at 500ma RMS.
DRV8825 8 microstep 5rpm 24volts with TL-Smoother. Driver output current set at 500ma RMS.
DRV8825 8 microstep 100rpm 12volts. Driver output current set at 500ma RMS.
DRV8825 8 microstep 100rpm 12volts with TL-Smoother. Driver output current set at 500ma RMS.
DRV8825 8 microstep 100rpm 24volts. Driver output current set at 500ma RMS.
DRV8825 8 microstep 100rpm 24volts with TL-Smoother. Driver output current set at 500ma RMS.
Temperature Testing. I ran a 60 minute run test for 1.0 volt Vref voltage setting. The driver was set for 16 microstepping, 24 volts and spinning a motor continuously at 100rpm. Ambient room temperature was 27C and no cooling fan was used. The supplied heatsink was used to cool the top of the driver board. A K type thermocouple was wedged between two fins to read the heatsink temperature.
The heatsink reached 97C and at no time did the driver shutdown from overheating.
Jim's Embeddedtronics 