AN2030 Datasheet, PDF (9/13 Pages) STMicroelectronics – BACK EMF DETECTION DURING PWM ON TIME BY ST7MC

BACK EMF DETECTION DURING PWM ON TIME BY ST7MC
Figure 9. (A) Rising edge of zero crossing for back EMF detection during on time; (B)
falling edge of zero crossing for back EMF during on time.
(A)
(B)
Figure 10 demonstrates that the system is able to run at 100% duty cycle, and the zero
crossing happens at the half of the dc bus voltage.
Figure 10. Waveforms for 100% duty cycle operation.
The software needs some modification as well, which is listed in the appendix.
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