Abov AC30M1x64 User Manual page 206

AC30M1x64/1x32
12.4.6 PWM Dead-time operation
To prevent external short condition, the MPWM provide dead time function. This function is only available for motor
pwm mode. When one of H-side or L-side output changes to active level, amount of dead time will be inserted if
DTEN.MP.DTR bit is enabled.
The duration of dead time is decided a value in DT.MP.DTR[7:0] field.
When DTCLK = 0, the dead time duration = DT[7:0] * (PWM clock period * 4)
When DTCLK = 1, the dead time duration = DT[7:0] * (PWM clock period * 16)
The pwm counter reached at duty value, the pwm output is masked and dead time counter starts to run. When dead
time counter reached the value in DT[7:0] register, the output mask is disabled.
Figure is an example of dead time operation in 1 channel symmetric mode.
MP.DUH/V/W
MP0UH
MP0VH
MP0UH
MP0VH
Below figure shows in case of 1-channel asymmetric mode operation.
MP.DUL/V/W
MP.DUH/V/W
MP0UH
In case of 2-channel symmetric mode, the dead time function is no available. So the dead condition is generated by
each channel duty control.
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MP.CNT
Figure 12.7 PWM Dead-time operation timing diagram (Symmetric mode)
MP.CNT
MP0VH
MP0UH
MP0VH
Figure 12.8 PWM Dead-time operation timing diagram (Asymmetric mode)
MP.DTR
MP.DTR
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MP.DTR
MP.DTR
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