SLVSD14A June 2017 – June 2020 DRV10983-Q1
After it is determined that the motor is stationary and after completing the motor initialization with either align or IPD, the DRV10983-Q1 device begins to accelerate the motor. This acceleration is accomplished by applying a voltage determined by the open-loop current setting (OpenLCurr[1:0]) to the appropriate drive state and by increasing the rate of commutation without regard to the real position of the motor (referred to as open-loop operation). The function of the open-loop operation is to drive the motor to a minimum speed so that the motor generates sufficient BEMF to allow the commutation control logic to accurately drive the motor.
Table 5 lists the configuration options that can be set in register to optimize the initial motor acceleration stage for different applications.
|DESCRIPTION||REG. NAME||CONFIGURATION BITS||MIN. VALUE||MAX. VALUE|
|Open- to closed-loop threshold||CONFIG4||Op2ClsThr[4:0]||0.8 Hz||204.8 Hz|
|Align time||CONFIG4||AlignTime[2:0]||40 ms||5.3 s|
|First-order accelerate||CONFIG4||StAccel[2:0]||0.019 Hz/s||76 Hz/s|
|Second-order accelerate||CONFIG4||StAccel2[2:0]||0.0026 Hz/s2||57 Hz/s2|
|Open-loop current setting||CONFIG3||OpenLCurr[1:0]||200 mA||1.6 A|
|Align current setting||150 mA||1.2 A|
|Open-loop current ramping||CONFIG3||OpLCurrRt[2:0]||0.023 VCC/s||6 VCC/s|