powerSTEP01
Functional description
Figure 8. Automatic Full-step switching in Boost mode
V
peak
Phase A
V
peak
Phase B
Full-step
Microstepping
Microstepping
(2N+1) x π /4
(2N+1) x π/4
AM12850v1
7.5
7.6
Absolute position counter
An internal 22-bit register (ABS_POS) records all the motor motions according to the
selected step mode; the stored value unit is equal to the selected step mode (full, half,
quarter, etc.). The position range is from -221 to +221-1 steps (see Section 11.1.1).
Programmable speed profiles
The user can easily program a customized speed profile defining independently
acceleration, deceleration, maximum and minimum speed values by ACC, DEC,
MAX_SPEED and MIN_SPEED registers respectively (see Section 11.1.5, 11.1.6, 11.1.7
and 11.1.8).
When a command is sent to the device, the integrated logic generates the microstep
frequency profile that performs a motor motion compliant to speed profile boundaries.
All acceleration parameters are expressed in step/tick2 and all speed parameters are
expressed in step/tick; the unit of measurement does not depend on the selected step
mode. Acceleration and deceleration parameters range from 2-40 to (212-2)
·
2-40 step/tick2
(equivalent to 14.55 to 59590 step/s2).
Minimum speed parameter ranges from 0 to (212-1)
step/s).
Maximum speed parameter ranges from 2-18 to (210-1)
15610 step/s).
·
2-24 step/tick (equivalent to 0 to 976.3
2-18 step/tick (equivalent to 15.25 to
·
DocID025022 Rev 1
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STMICROELECTRONICS [ ST ]
