SLVSH04 November   2023 DRV8214

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Revision History
  6. 5 Device Comparison
  7. 6 Pin Configuration and Functions
  8. 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 I2C Timing Requirements
    7. 7.7 Timing Diagrams
    8. 7.8 Typical Operating Characteristics
  9. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 External Components
      2. 8.3.2 Summary of Features
      3. 8.3.3 Bridge Control
      4. 8.3.4 Current Sense and Regulation (IPROPI)
        1. 8.3.4.1 Current Sensing and Current Mirror Gain Selection
        2. 8.3.4.2 Current Regulation
          1. 8.3.4.2.1 Fixed Off-Time Current Regulation
          2. 8.3.4.2.2 Cycle-By-Cycle Current Regulation
      5. 8.3.5 Stall Detection
      6. 8.3.6 Ripple Counting
        1. 8.3.6.1 Ripple Counting Parameters
          1. 8.3.6.1.1  Motor Resistance Inverse
          2. 8.3.6.1.2  Motor Resistance Inverse Scale
          3. 8.3.6.1.3  KMC Scaling Factor
          4. 8.3.6.1.4  KMC
          5. 8.3.6.1.5  Filter Damping Constant
          6. 8.3.6.1.6  Filter Input Scaling Factor
          7. 8.3.6.1.7  Ripple Count Threshold
          8. 8.3.6.1.8  Ripple Count Threshold Scale
          9. 8.3.6.1.9  T_MECH_FLT
          10. 8.3.6.1.10 VSNS_SEL
          11. 8.3.6.1.11 Error Correction
            1. 8.3.6.1.11.1 EC_FALSE_PER
            2. 8.3.6.1.11.2 EC_MISS_PER
        2. 8.3.6.2 RC_OUT Output
        3. 8.3.6.3 Ripple Counting with nFAULT
      7. 8.3.7 Motor Voltage and Speed Regulation
        1. 8.3.7.1 Internal Bridge Control
        2. 8.3.7.2 Setting Speed/Voltage Regulation Parameters
          1. 8.3.7.2.1 Speed and Voltage Set
          2. 8.3.7.2.2 Speed Scaling Factor
        3. 8.3.7.3 Soft-Start and Soft-Stop
          1. 8.3.7.3.1 TINRUSH
      8. 8.3.8 Protection Circuits
        1. 8.3.8.1 Overcurrent Protection (OCP)
        2. 8.3.8.2 Thermal Shutdown (TSD)
        3. 8.3.8.3 VCC Undervoltage Lockout (UVLO)
        4. 8.3.8.4 Overvoltage Protection (OVP)
        5. 8.3.8.5 nFAULT Output
    4. 8.4 Device Functional Modes
      1. 8.4.1 Active Mode
      2. 8.4.2 Low-Power Sleep Mode
      3. 8.4.3 Fault Mode
    5. 8.5 Programming
      1. 8.5.1 I2C Communication
        1. 8.5.1.1 I2C Write
        2. 8.5.1.2 I2C Read
    6. 8.6 Register Map
      1. 8.6.1 DRV8214_STATUS Registers
      2. 8.6.2 DRV8214_CONFIG Registers
      3. 8.6.3 DRV8214_CTRL Registers
  10. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application: Brushed DC Motor
      1. 9.2.1 Design Requirements
      2. 9.2.2 Stall Detection
        1. 9.2.2.1 Application Description
          1. 9.2.2.1.1 Stall Detection Timing
          2. 9.2.2.1.2 Hardware Stall Threshold Selection
      3. 9.2.3 Ripple Counting Application
        1. 9.2.3.1 Tuning Ripple Counting Parameters
          1. 9.2.3.1.1 Resistance Parameters
          2. 9.2.3.1.2 KMC and KMC_SCALE
            1. 9.2.3.1.2.1 Case I
            2. 9.2.3.1.2.2 Case II
              1. 9.2.3.1.2.2.1 Method 1: Tuning from Scratch
                1. 9.2.3.1.2.2.1.1 Tuning KMC_SCALE
                2. 9.2.3.1.2.2.1.2 Tuning KMC
              2. 9.2.3.1.2.2.2 Method 2: Using the Proportionality factor
                1. 9.2.3.1.2.2.2.1 Working Example
          3. 9.2.3.1.3 Advanced Parameters
            1. 9.2.3.1.3.1 Filter Constants
              1. 9.2.3.1.3.1.1 FLT_GAIN_SEL
              2. 9.2.3.1.3.1.2 FLT_K
            2. 9.2.3.1.3.2 T_MECH_FLT
            3. 9.2.3.1.3.3 VSNS_SEL
            4. 9.2.3.1.3.4 Additional Error Corrector Parameters
              1. 9.2.3.1.3.4.1 EC_FALSE_PER
              2. 9.2.3.1.3.4.2 EC_MISS_PER
      4. 9.2.4 Motor Voltage
      5. 9.2.5 Motor Current
      6. 9.2.6 Application Curves
  11. 10Power Supply Recommendations
    1. 10.1 Bulk Capacitance
  12. 11Layout
    1. 11.1 Layout Guidelines
  13. 12Mechanical, Packaging, and Orderable Information
    1. 12.1 Tape and Reel Information

Package Options

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

This section describes how to select INV_R and INV_R_SCALE. The first step is to find the motor resistance. This can be done in three ways:

  1. Use the motor resistance value mentioned in the data sheet of the motor. If this is not available, use one of the other methods listed below.
  2. Perform a voltage sweep at the motor terminals, stall the motor at each voltage level, and measure the motor current. Please note that at least 10 measurements are required at every voltage level whilst rotating the motor by approximately 30° for each measurement. This is because it is unknown if the commutator segments are in contact with the brushes in a particular motor position which renders a lower, incorrect motor resistance value. If motor resistance from the motor's data sheet is unavailable, then this method is recommended to obtain the value of motor resistance. Take the average of all values to calculate motor resistance.
  3. Measure the motor resistance using a digital multimeter. Please note that this process also needs to be done at every voltage level for 10 measurements each and then averaged out at the end for the same reason as mentioned above.

Once the motor resistance value is found, select an appropriate value of INV_R_SCALE and calculate INV_R. The formula to calculate INV_R is:

Equation 9. I N V _ R   = 1 M o t o r   R e s i s t a n c e × I N V _ R _ S C A L E

For example, if the motor resistance is 25 Ω, we have the following possible results based on the choice of INV_R_SCALE:

Table 9-2 Selection Example for INV_R_SCALE and INV_R
Bit INV_R_SCALE value INV_R_SCALE/Motor Resistance

(Actual Value)

 Rounded Value

INV_R

 Comment
00b 2 2/25=0.08 0 Do not select, since output is 0.
01b 64 64/25=2.56 3 Avoid selecting, since low bit precision.
10b 1024 1024/25=40.96 41 Can select this value.
11b 8192 8192/25=327.68 328 Cannot select this value because 328 exceeds the maximum limit for INV_R (255).