SLLSFU1A December 2023 – July 2024 MCF8315C
PRODMIX
The MCF8315C supports two different modulation schemes, namely, continuous and discontinuous space vector PWM modulation schemes. In continuous PWM modulation, all the three phases switch all the time as per the defined switching frequency. In discontinuous PWM modulation, one of the phases is clamped to ground for 120o electrical period, and the other two phases are pulse width modulated. The modulation scheme is configured using PWM_MODE. Figure 6-43 shows the modulated average phase voltages for different modulation schemes.
Continuous modulation helps in reducing current ripple for motors having low inductance but it results in higher switching losses because all three phases are switching. Discontinuous modulation has lower switching losses due to only two phases switching at a time, but higher current ripple.