List of figures

Document alternate name

4/22

DocID18343 Rev 3

List of figures

Figure 1.

L9942 microstepping mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Figure 2.

L9942 current regulation block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Figure 3.

Phase shift in an unloaded motor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Figure 4.

A partially loaded motor note the phase shift of the BEMF. . . . . . . . . . . . . . . . . . . . . . . . . . 9

Figure 5.

A fully loaded motor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Figure 6.

Typical motor phase winding components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Figure 7.

Back EMF and phase current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Figure 8.

Back EMF waveforms on an active stepper motor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Figure 9.

Unloaded motor driven in full step mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Figure 10.

A loaded motor driven in full step mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Figure 11.

Motor in hard stall . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Figure 12.

Two instances where the motor is in stall but allowed to "vibrate" . . . . . . . . . . . . . . . . . . . 14

Figure 13.

Simplified block diagram of back EMF detection circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Figure 14.

BEMF histogram of an unloaded motor at 20C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Figure 15.

Combined histograms of an unloaded and stalled motor at both hot and cold . . . . . . . . . . 16

Figure 16.

Histogram of stall detection times in one motor (right is a zoom of the left) . . . . . . . . . . . . 17