Datasheet

Power bridges L6460
66/139 Doc ID 17713 Rev 1
The allowable control modes are as follows:
1. Stepping sequence left to external microcontroller: in this mode the current level in
each motor winding is set by the microcontroller via the serial interface.
2. Full step: in this mode the electrical angle will change by 90° steps at each StepReq
signal transition. There are two possibilities:
– Normal step (two phases on): in normal step mode both windings are energized
simultaneously and the current will be alternately reversed. The resulting electrical
angles will be 45°, 135°, 225° and 315°.
– Wave drive (one phase on): In wave drive mode each winding is alternately
energized and reversed. The resulting electrical angles will be 90°, 180° and 270°
and 360°.
3. Half step: in this mode, one motor winding is energized and then two windings
alternately so the electrical angles the motor will do when rotating in clockwise direction
and using the same current limit in both the phases are: 45°, 90°, 135°, 180°, 225°,
270°, 315° and 360°.
4. Microstepping: in this mode the current in each motor winding has a quasi sinusoidal
profile. The increment between each step is obtained at each transition of StepCmd bit
in StepCmd register. The difference between each step could be chosen (4, 8 or 16
levels for each phase) according to following table:
Note: When in 1/16 step mode, the best phase approximation of sinusoidal wave, is obtained by
repeating the “F” step as follows: 0, 1, 2, 3, … , D, E, F, F, F, E, D, … , 3, 2, 1, 0
When internal stepping sequence generation is used, the stepping direction is set by the
StepDir bit according to the Ta ble 23 .
Table 21. Sequencer driver
StepFromGpio Sequencer driver
0 StepCmd bit in StepCmd register.
1 GPIO12 input pin.
Table 22. Stepper driving mode
StepCtrlMode[2:0] Control mode Description
000 or 111 No Control
Stepping sequence control left to the external
controller
001 Half Step Half step
010 Normal Step Full step (two phases on)
011 Wave Drive Full step (one phase on)
100 1/4 Step Four micro steps
101 1/8 Step Eight micro steps
110 1/16 Step Sixteen micro steps