DRV8461SPWPR datasheet(25/117 Pages) TI

25 / 117 page

Pull up the nHOME to a 5-V, 3.3-V or 1.8-V supply using a pull-up resistor. For a 5-V pullup, the nHOME pin can

be tied to the DVDD pin with a resistor. For a 3.3-V or 1.8-V pullup, an external supply must be used.

Traces from top to bottom: BOUT2, BOUT1, coil B current, coil A current, nHOME

Figure 7-6. nHOME Output Waveform

7.3.6 Automatic Microstepping Mode

When the DRV8461 is operating with SPI interface, automatic microstepping mode interpolates the input step

pulses to generate a current waveform corresponding to higher resolution microstep. This results in smooth

sinusoidal current and noiseless operation at any step frequency.

• If automatic microstepping is disabled, the system controller will be forced to output high frequency STEP

signals to generate high resolution microstepping current waveforms.

• With automatic microstepping enabled, smooth current waveform can be generated by low frequency STEP

signals.

– This drastically reduces controller overhead and is beneficial for applications such as 3D printer, factory

automation and medical.

• It should be ensured that the interpolated frequency does not fall in the resonant frequency band of the

stepper motor.

The EN_AUTO bit should be 1b to enable the automatic microstepping mode.

Motor Angle

STEP

Figure 7-7. Automatic Microstepping Interpolation

Figure 7-7 shows increment in motor angle with and without automatic microstepping. Without automatic

microstepping (red plot), the motor angle increments by a large amount on every step input active edge.

Automatic microstepping (green plot) results in a much smoother change in motor angle.

The DRV8461 supports interpolation to 1/32, 1/64, 1/128 or 1/256 microstepping levels, configured by the

RES_AUTO bits as shown in Table 7-13. Interpolation setting can be changed on the fly.

www.ti.com

DRV8461

SLOSE98 – DECEMBER 2022

Submit Document Feedback

Product Folder Links: DRV8461

DRV8461SPWPR 数据表(PDF) 25 Page - Texas Instruments