SLVSCP2F January   2015  – June 2020 DRV10975

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Application Schematic
  4. 4 Revision History
  5. 5 Description (continued)
  6. 6 Pin Configuration and Functions
    1.     Pin Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Regulators
        1. 8.3.1.1 Step-Down Regulator
        2. 8.3.1.2 3.3-V and 1.8-V LDO
      2. 8.3.2 Protection Circuits
        1. 8.3.2.1 Thermal Shutdown
        2. 8.3.2.2 Undervoltage Lockout (UVLO)
        3. 8.3.2.3 Overcurrent Protection (OCP)
        4. 8.3.2.4 Lock
      3. 8.3.3 Motor Speed Control
      4. 8.3.4 Sleep or Standby Condition
      5. 8.3.5 Non-Volatile Memory
    4. 8.4 Device Functional Modes
      1. 8.4.1  Motor Parameters
        1. 8.4.1.1 Motor Phase Resistance
        2. 8.4.1.2 BEMF Constant
      2. 8.4.2  Starting the Motor Under Different Initial Conditions
        1. 8.4.2.1 Case 1 – Motor Is Stationary
        2. 8.4.2.2 Case 2 – Motor Is Spinning in the Forward Direction
        3. 8.4.2.3 Case 3 – Motor Is Spinning in the Reverse Direction
      3. 8.4.3  Motor Start Sequence
        1. 8.4.3.1 ISD
        2. 8.4.3.2 Motor Resynchronization
        3. 8.4.3.3 Reverse Drive
        4. 8.4.3.4 Motor Brake
        5. 8.4.3.5 Motor Initialization
          1. 8.4.3.5.1 Align
          2. 8.4.3.5.2 Initial Position Detect (IPD)
            1. 8.4.3.5.2.1 IPD Operation
            2. 8.4.3.5.2.2 IPD Release Mode
            3. 8.4.3.5.2.3 IPD Advance Angle
          3. 8.4.3.5.3 Motor Start
        6. 8.4.3.6 Start-Up Timing
      4. 8.4.4  Start-Up Current Setting
        1. 8.4.4.1 Start-Up Current Ramp-Up
      5. 8.4.5  Closed Loop
        1. 8.4.5.1 Half Cycle Control and Full Cycle Control
        2. 8.4.5.2 Analog Mode Speed Control
        3. 8.4.5.3 Digital PWM Input Mode Speed Control
        4. 8.4.5.4 I2C Mode Speed Control
        5. 8.4.5.5 Closed Loop Accelerate
        6. 8.4.5.6 Control Coefficient
        7. 8.4.5.7 Commutation Control Advance Angle
      6. 8.4.6  Current Limit
        1. 8.4.6.1 Acceleration Current Limit
      7. 8.4.7  Lock Detect and Fault Handling
        1. 8.4.7.1 Lock0: Lock Detection Current Limit Triggered
        2. 8.4.7.2 Lock1: Abnormal Speed
        3. 8.4.7.3 Lock2: Abnormal Kt
        4. 8.4.7.4 Lock3 (Fault3): No Motor Fault
        5. 8.4.7.5 Lock4: Open Loop Motor Stuck Lock
        6. 8.4.7.6 Lock5: Closed Loop Motor Stuck Lock
      8. 8.4.8  AVS Function
        1. 8.4.8.1 Mechanical AVS Function
      9. 8.4.9  PWM Output
      10. 8.4.10 FG Customized Configuration
        1. 8.4.10.1 FG Output Frequency
        2. 8.4.10.2 FG Open-Loop and Lock Behavior
      11. 8.4.11 Diagnostics and Visibility
        1. 8.4.11.1 Motor Status Readback
        2. 8.4.11.2 Motor Speed Readback
          1. 8.4.11.2.1 Two-Byte Register Readback
        3. 8.4.11.3 Motor Electrical Period Readback
        4. 8.4.11.4 BEMF Constant Readback
        5. 8.4.11.5 Motor Estimated Position by IPD
        6. 8.4.11.6 Supply Voltage Readback
        7. 8.4.11.7 Speed Command Readback
        8. 8.4.11.8 Speed Command Buffer Readback
        9. 8.4.11.9 Fault Diagnostics
    5. 8.5 Register Maps
      1. 8.5.1 I2C Serial Interface
      2. 8.5.2 Register Map
      3. 8.5.3 Register Definition
        1. Table 9. Register Description
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Third-Party Products Disclaimer
    2. 12.2 Documentation Support
      1. 12.2.1 Related Documentation
    3. 12.3 Trademarks
    4. 12.4 Electrostatic Discharge Caution
    5. 12.5 Receiving Notification of Documentation Updates
    6. 12.6 Community Resources
    7. 12.7 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

8.4.1.2 BEMF Constant

The BEMF constant, Kt[6:0] describes the motors phase-to-phase BEMF voltage as a function of the motor velocity.

The measured BEMF constant (Kt) needs to be converted to a 7-bit digital register value Kt[6:0] to program the BEMF constant value. The digital register value can be determined as follows:

  1. Convert the measured Kt to a weighted digital value: Ktph_dig = 1442 × Kt
  2. Encode the digital value such that Ktph_dig = Kt[3:0] << Kt[4:6].

The maximum Kt that can be programmed is 1330 mV/Hz. This represents a digital value of 1920 and an encoded Kt[6:0] value of 0x7Fh. The minimum Kt that can be programmed is 0.7 mV/Hz, which represents a digital value of 1 and an encoded Kt[6:0] value of 0x01h.

For convenience, the encoded value of Kt[6:0] may also be obtained from Table 3.

Table 3. BEMF Constant Look-Up Table

Kt (mV/Hz) Kt[6:0] HEX Kt (mV/Hz) Kt [6:0] HEX Kt (mV/Hz) Kt [6:0] HEX
0 000 0000 00 22.3 010 1000 28 178 101 1000 58
0.7 000 0001 01 25.1 010 1001 29 200 101 1001 59
1.39 000 0010 02 27.8 010 1010 2A 223 101 1010 5A
2.09 000 0011 03 30.6 010 1011 2B 245 101 1011 5B
2.78 000 0100 04 33.4 010 1100 2C 267 101 1100 5C
3.48 000 0101 05 36.2 010 1101 2D 290 101 1101 5D
4.18 000 0110 06 39 010 1110 2E 312 101 1110 5E
4.88 000 0111 07 41.8 010 1111 2F 334 101 1111 5F
5.57 000 1000 08 44.6 011 1000 38 356 110 1000 68
6.27 000 1001 09 50.2 011 1001 39 401 110 1001 69
6.97 000 1010 0A 55.7 011 1010 3A 446 110 1010 6A
7.66 000 1011 0B 61.3 011 1011 3B 490 110 1011 6B
8.36 000 1100 0C 66.9 011 1100 3C 535 110 1100 6C
9.06 000 1101 0D 72.5 011 1101 3D 580 110 1101 6D
9.76 000 1110 0E 78 011 1110 3E 624 110 1110 6E
10.4 000 1111 0F 83.6 011 1111 3F 669 110 1111 6F
11.1 001 1000 18 89.2 100 1000 48 713 111 1000 78
12.5 001 1001 19 100 100 1001 49 803 111 1001 79
13.9 001 1010 1A 111 100 1010 4A 892 111 1010 7A
15.3 001 1011 1B 122 100 1011 4B 981 111 1011 7B
16.7 001 1100 1C 133 100 1100 4C 1070 111 1100 7C
18.1 001 1101 1D 145 100 1101 4D 1160 111 1101 7D
19.5 001 1110 1E 156 100 1110 4E 1240 111 1110 7E
20.9 001 1111 1F 167 100 1111 4F 1330 111 1111 7F