ST92141 - 3-PHASE INDUCTION MOTOR CONTROLLER (IMC)
INDUCTION MOTOR CONTROLLER (Cont’d)
PWM signals generation in Classical mode
In this mode, each of the three PWM signals set to
‘0’ when the PWM Counter reaches, in up-count-
ing, the corresponding 11-bit Compare register
value and they are set to ‘1’ when the PWM Coun-
ter is cleared.
If the 11-bit Compare register value is greater than
the extended Compare 0 register (the 11th bit is
set to ‘0’), the corresponding PWM output signal is
held at ‘1’.
If the 11-bit Compare register value = 0, the corre-
sponding PWM output signal is held at ‘0’.
Figure 66 shows some Classical PWM waves in
an example where the Compare 0 register value =
8.
Figure 66. Classical PWM Waveforms (Compare 0 Register = 8)
0
1
2
3
4
5
6
7
8
0
1
1
2
3 ‘1’
4 ‘0’
1 Compare Register value = 4
2 Compare Register value = 8
3 Compare Register value > 8
4 Compare Register value = 0
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