4 Motor Control Library Specifications

  • Motor Type support: 3-phase BLDC or PMSM
  • Feedback type: Sensorless with BEMF measurement or HALL sensor
  • PWM Drive frequency: Configurable from 15 kHz to 45 kHz
  • Drive Modulation capabilities: Block Commutation (Trapezoidal), Sinusoidal (Sinus, SVPWM, Saddle Mode)
  • Drive to Feedback synchronization method: Phase-Locked Loop (PLL) approximation
  • Electrical RPM modulated frequency: 20-2000 Hz
  • Synchronization lost for speeds lower than: BEMF ~15% Motor RPM; Hall ~20 Hz
  • Ramp APIs: Single Ramp-up and Ramp-down with only two points (no multipoint ramp)
  • Minimum to maximum speed acceleration time: 1.6384s (one bit increment from 16-bit speed)
  • Current measurement capabilities: Comparator peak trigger and Analog-to-Digital (ADC) averaged accumulation
  • ADC resolution: 12-bit single measurement/16-bit average accumulation
  • Dead-Time control: 8-bit control with 50 ns steps, 0-12750 ns
  • Open-loop response time on step change: 300-500 ms
  • Closed-loop response time on step change: 500-750 ms
  • Fault capabilities: Over-Voltage Protection (OVP), Under-Voltage Protection (UVP), Temperature monitoring, Over-Current Protection (OCP) – peak and average
  • Fault response time (Peak current using comparator): Minimum 100-150 ns (see Figure 4-1)
  • Fault response time (using ADC): 30-35 ms with analog filter enabled (software filtering to get smoother values) or 1.5-2 ms with analog filter disabled (see Figure 4-2)
  • Feedback response time: One drive PWM period (50 us for 20 kHz drive)
  • Total Interrupt window occupation in Sinusoidal mode: ~23 us (see Figure 4-3)
  • Total Interrupt window occupation in Trapezoidal mode: ~19 µs between sectors or 30 µs at sector switch (see Figure 4-4)
  • Delay safe time between stop and restart: Ramp-down duration [ms] divided by two is the safe time between stop and restart after the ramp-down finish
  • Phase advance control: Fixed 0-90 degrees
  • Hall sensor detection latency: One drive PWM period for detection and from 30 to 120 electrical degrees for adjustment
  • BEMF detection latency: One drive PWM period for detection and from 30 to 120 electrical degrees for adjustment
  • Sinusoidal distortion capabilities: No
  • Regen breaking capabilities: No
  • Start while the motor is spinning capabilities (windmilling): No
  • Field weakening capabilities: No
Figure 4-1. Peak Current Trigger Fault Protection Response Time
Figure 4-2. Overvoltage Fault Protection Response Time
Figure 4-3. Interrupt Window Occupation in Sinusoidal Drive Mode
Figure 4-4. Interrupt Window Occupation in Trapezoidal Drive Mode

Based on the MOSFET switching frequency, the Interrupt window is split into two consecutive Interrupt Service Routines (ISRs) or executed in a single ISR: When the PWM frequency is above 20 kHz, the computation is done during two ISRs, when under 20 kHz, only one ISR. Examples for 20 kHz and 40 kHz, see the figure below:

Figure 4-5. Motor Interrupt Window Time Diagram