Pulse-Width Modulator for Motor Control (PWMMC)
Output Control
MC68HC908MR16/MC68HC908MR32 — Rev. 4.0 Advance Information
MOTOROLA Pulse-Width Modulator for Motor Control (PWMMC) 151
register value. This correction is further d escr i bed i n 9.6 .3 Top/Botto m
Correction with Motor Phase Current Polarity Sensing.
Further examples of dead-time insertion are shown in Figure 9-15 and
Figure 9-16. Figure 9-15 shows the effects of dead-time inserti on at the
duty cycle boundaries (near 0 percent and 100 percent duty cycles).
Figure 9-16 shows the effects of dead-time insertion on pulse widths
smaller than the dead-time.
Figure 9-14. Effects of Dead-Time Insertion
PWM VALUE = 2 PWM VALUE = 2 PWM VALUE = 3
PWM1 W/
PWM2 W/
PWM1 W/
PWM2 W/
NO DEAD-TIME
NO DEAD-TIME
DEAD-TIME = 2
DEAD-TIME = 2 2
2
2
2
UP/DOWN COUNTER
MODULUS = 4
22