Phase current control: voltage mode
powerSTEP01
Motor supply voltage compensation can be enabled setting high the EN_VSCOMP bit of the
CONFIG register (seeTable 45). If the EN_VSCOMP bit is low, the compensation is disabled
and the internal analog to digital converter is at the user’s disposal; the sampling rate is
always equal to PWM frequency.
8.6
Winding resistance thermal drift compensation
The higher the winding resistance the greater the voltage to be applied in order to obtain the
same phase current.
The powerSTEP01 integrates a register (K_THERM) which can be used to compensate
phase resistance increment due to temperature rising.
The value in the K_THERM register (Section 11.1.15) multiplies duty cycle value allowing
the higher phase resistance value to be faced.
The compensation algorithm and the eventual motor temperature measurement should be
implemented by microcontroller firmware.
42/90
DocID025022 Rev 1
STMICROELECTRONICS [ ST ]
