JAJSEC0E January 2018 – March 2021 DRV10974
PRODUCTION DATA
After the motor is confirmed to be stationary and after completing the motor initialization, the DRV10974 device begins to accelerate the motor. This acceleration is accomplished by applying a voltage to the motor at the appropriate drive state and increasing the rate of commutation without regard to the actual 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 drive the motor accurately.
The motor start-up profile can be configured using an external resistor to set the acceleration profile before transitioning to closed-loop operation. Figure 7-14 shows this acceleration profile. During closed-loop operation the RMP pin controls the closed-loop acceleration and deceleration. Table 7-2 lists the selectable acceleration parameters.
RMP SELECTION | RRMP [kΩ](1) | Accel2 [Hz/s2] | Accel1 [Hz/s] | CLOSED-LOOP-ACCELERATION TRANSITION TIME [s](2) | CLOSED-LOOP-DECELERATION TRANSITION TIME [s](3) |
---|---|---|---|---|---|
0 | 7.32 | 0.22 | 4.6 | 2.7 | 44 |
1 | 10.7 | 1.65 | 9.2 | 2.7 | 22 |
2 | 14.3 | 1.65 | 15 | 1 | 22 |
3 | 17.8 | 3.3 | 25 | 1 | 11 |
4 | 22.1 | 7 | 25 | 0.2 | 44 |
5 | 28 | 7 | 35 | 0.2 | 22 |
6 | 34 | 14 | 50 | 0.2 | 22 |
7 | 41.2 | 27 | 75 | 0.2 | 11 |
8 | 49.9 | 27 | 75 | 5.4 | 11 |
9 | 59 | 14 | 50 | 8 | 22 |
10 | 71.5 | 7 | 35 | 11 | 22 |
11 | 86.6 | 7 | 25 | 22 | 44 |
12 | 105 | 3.3 | 25 | 5.4 | 11 |
13 | 124 | 1.65 | 15 | 8 | 22 |
14 | 150 | 1.65 | 9.2 | 11 | 22 |
15 | 182 | 0.22 | 4.6 | 22 | 44 |