POWERSTEP01 datasheet(25/92 Pages) STMICROELECTRONICS

25 / 92 page

DocID025022 Rev 5

25/92

powerSTEP01

Functional description

Figure 8. Automatic Full-step switching in Boost mode

7.5

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 on page

53).

7.6

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 on page 54,

11.1.6 on page 54, 11.1.7 on page 54 and 11.1.8 on page 55).

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) · 2-24 step/tick (equivalent to 0 to 976.3

step/s).

Maximum speed parameter ranges from 2-18 to (210-1) · 2-18 step/tick (equivalent to 15.25 to

15610 step/s).

Phase A

Phase B

(2N+1) x π /4

(2N+1) x π/4

Full-step

Microstepping

peak

AM12850v1

POWERSTEP01 Datasheet(PDF) 25 Page - STMicroelectronics