JAJSJS9A july 2023 – july 2023 DRV8262
PRODUCTION DATA
The following schematic shows the DRV8262 driving a stepper motor.
The full-scale current (IFS) is the maximum current driven through either winding. This quantity will depend on the VREF voltage and the resistor connected from IPROPI pin to ground.
IFS x AIPROPI = VVREF / RIPROPI
The maximum allowable voltage on the VREF pins is 3.3 V. DVDD can be used to provide VREF through a resistor divider.
The IFS current must also follow Equation 6 to avoid saturating the motor. VM is the motor supply voltage, and RL is the motor winding resistance.
If the target motor speed is too high, the motor will not spin. Make sure that the motor can support the target speed.
For a desired motor speed (v), microstepping level (nm), and motor full step angle (θstep), determine the frequency of the input waveform as follows -
θstep can be found in the stepper motor data sheet or written on the motor itself.
The frequency ƒstep gives the frequency of input change on the DRV8262. 1/ ƒstep = tSTEP on the diagram below. Equation 8 shows an example calculation for a 120 rpm target speed and 1/2 step.
The IPROPI pins output the current of each H-bridge, corresponding to current of coil A and coil B of the stepper motor during drive and slow-decay (high-side recirculation) modes.