SLVSDN2E January   2018  – March 2021 DRV10974

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Speed Input and Control
      2. 7.3.2 Motor Direction Change
      3. 7.3.3 Motor-Frequency Feedback (FG)
      4. 7.3.4 Lock Detection
        1. 7.3.4.1 Lock Kt Measure
        2. 7.3.4.2 Lock No Motor
        3. 7.3.4.3 Lock Open Loop Abnormal
        4. 7.3.4.4 Lock BEMF Abnormal
        5. 7.3.4.5 Lock Closed Loop Abnormal
        6. 7.3.4.6 Lock Speed Abnormal
      5. 7.3.5 Soft Current-Limit
      6. 7.3.6 Short-Circuit Current Protection
      7. 7.3.7 Overtemperature Protection
      8. 7.3.8 Undervoltage Protection
    4. 7.4 Device Functional Modes
      1. 7.4.1 Spin-Up Settings
        1. 7.4.1.1 Motor Start
        2. 7.4.1.2 Initial Speed Detect
        3. 7.4.1.3 Align
      2. 7.4.2 Open-Loop Acceleration
      3. 7.4.3 Start-Up Current Sensing
      4. 7.4.4 Closed Loop
      5. 7.4.5 Control Advance Angle
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
      3. 8.2.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Device Support
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Support Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

7.4.2 Open-Loop Acceleration

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.

Table 7-2 Acceleration Profile Settings
RMP SELECTIONRRMP [kΩ](1)Accel2 [Hz/s2]Accel1 [Hz/s]CLOSED-LOOP-ACCELERATION TRANSITION TIME [s](2)CLOSED-LOOP-DECELERATION TRANSITION TIME [s](3)
07.320.224.62.744
110.71.659.22.722
214.31.6515122
317.83.325111
422.17250.244
5287350.222
63414500.222
741.227750.211
849.927755.411
9591450822
1071.57351122
1186.67252244
121053.3255.411
131241.6515822
141501.659.21122
151820.224.62244
(1) All resistors are ±1%
(2) Time to transition from 0 to 100% duty cycle.
(3) Time to transition from 100% to 0% duty cycle.
GUID-CB16E8B2-326B-47A0-9F47-020AE66CB883-low.gifFigure 7-14 Start-Up Profile