SLOSE98A December 2022 – September 2023 DRV8461
PRODUCTION DATA
The first step in configuring the DRV8461 requires the desired motor speed and microstepping level. If the target application requires a constant speed, then a square wave with frequency ƒstep must be applied to the STEP pin. If the target motor speed is too high, the motor does not spin. Make sure that the motor can support the target speed. Use Equation 15 to calculate ƒstep for a desired motor speed (v), microstepping level (nm), and motor full step angle (θstep)
The value of θstep can be found in the stepper motor data sheet, or written on the motor. For example, the motor in this application is required to rotate at 1.8°/step for a target of 7.5 rpm at 1/16 microstep mode. Using Equation 15, ƒstep can be calculated as 400 Hz.
The microstepping level is set by the M0 and M1 pins or the MICROSTEP_MODE bits and can be any of the settings listed in Table 7-5. Higher microstepping results in a smoother motor motion and less audible noise, but requires a higher ƒstep to achieve the same motor speed.