POWERSTEP01 datasheet(40/92 Pages) STMICROELECTRONICS

Part #	POWERSTEP01

Description	System-in-package integrating microstepping controller and 10 A power MOSFETs

PDF	92 Pages

Scroll/Zoom	100%

Manufacturer	STMICROELECTRONICS [STMicroelectronics]

Direct Link	http://www.st.com

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40 / 92 page

Phase current control: voltage mode

powerSTEP01

40/92

DocID025022 Rev 5

Figure 16. Current distortion and compensation

The optimization can be enabled setting high the LSPD_OPT bit in the MIN_SPEED register

(Section 11.1.8 on page 55) and is active in a speed range from zero to MIN_SPEED. When

low speed optimization is enabled, speed profile minimum speed is forced to zero.

8.4

BEMF compensation

Using the speed information, a compensation curve is added to the amplitude of the voltage

waveform applied to the motor winding in order to compensate the BEMF variations during

acceleration and deceleration (see Figure 17).

The compensation curve is approximated by a stacked line with a starting slope (ST_SLP)

when speed is lower than a programmable threshold speed (INT_SPEED) and a fine slope

(FN_SLP_ACC and FN_SLP_DEC) when speed is greater than the threshold speed (see

sections 11.1.11 on page 56, 11.1.12 on page 56, 11.1.13 on page 57 and 11.1.14 on page

57).

phase

Without low speed optimizazion

ith low speed optimizazion

AM12851v1

Current distortion is heavily reduced

POWERSTEP01 Datasheet(PDF) 40 Page - STMicroelectronics