JAJU802A January 2022 – October 2022
Accurate current sensing is important to estimate the rotor angle and speed, and also have the best dynamic motor control. The current sensing parameters must match the hardware by setting the related parameters below.
Dead band time, the rising edge delay time must be greater than (high-side turn on time) + (low side turn-off time) of the power module, and the falling edge delay time must be greater than (high-side turn off time) + (low side turn-on time) of the power module as below setting for a power module used in the reference design.
//! \brief Defines the PWM deadband falling edge delay count (system clocks)
#define MTR1_PWM_DBFED_CNT 225 // 2.25us
//! \brief Defines the PWM deadband rising edge delay count (system clocks)
#define MTR1_PWM_DBRED_CNT 245 // 2.45us
Minimum duration of pulse width PWM, it speifies the must be grater than (Hardware delay time + Dead band time + Ringing duration + ADC sampling time)
//! \brief Defines the minimum duration, Clock Cycle
#define USER_M1_DCLINKSS_MIN_DURATION (480U)
Sample/hold delay time, it specifies the time delay from PWM output to ADC sample time for current sensing. The delay time is dependent on the hardware includes propagation delay of gate driver circuit and turn on/off delay of power FET, and is less than or equals to (Minimum duration - ADC sampling time).
//! \brief Defines the sample delay, Clock Cycle
#define USER_M1_DCLINKSS_SAMPLE_DELAY (455U)