EVAL6470H Datasheet, PDF(37/70 Page) STMicroelectronics – dSPIN fully integrated microstepping motor driver with motion engine and SPI

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EVAL6470H Datasheet, PDF (37/70 Pages) STMicroelectronics – dSPIN fully integrated microstepping motor driver with motion engine and SPI

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L6470

Phase current control

Figure 17. Motor supply voltage compensation circuit

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Motor supply voltage compensation can be enabled setting high the EN_VSCOMP bit of the

CONFIG register (see Table 22, Section 9.1.21). If the EN_VSCOMP bit is low, the

compensation is disabled and the internal analog-to-digital converter is at the userâs

disposal; sampling rate is always equal to PWM frequency.

7.6

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 L6470 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 (see Section 9.1.15) multiplies the duty cycle value

allowing a higher phase resistance value to be faced.

The compensation algorithm and the eventual motor temperature measurement should be

implemented by microcontroller firmware.

Doc ID16737 Rev 5

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