SLVSHO5 April   2024 DRV8215

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison
  6. 5 Pin Configuration and Functions
  7. 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 I2C Timing Requirements
    7. 6.7 Timing Diagrams
    8. 6.8 Typical Operating Characteristics
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 External Components
      2. 7.3.2 Summary of Features
      3. 7.3.3 Bridge Control
      4. 7.3.4 Current Sense and Regulation (IPROPI)
        1. 7.3.4.1 Current Sensing and Current Mirror Gain Selection
        2. 7.3.4.2 Current Regulation
          1. 7.3.4.2.1 Fixed Off-Time Current Regulation
          2. 7.3.4.2.2 Cycle-By-Cycle Current Regulation
      5. 7.3.5 Stall Detection
      6. 7.3.6 Motor Voltage and Speed Regulation
        1. 7.3.6.1 Internal Bridge Control
        2. 7.3.6.2 Setting Speed/Voltage Regulation Parameters
          1. 7.3.6.2.1 Speed and Voltage Set
          2. 7.3.6.2.2 Speed Scaling Factor
            1. 7.3.6.2.2.1 Target Speed Setting Example
          3. 7.3.6.2.3 Motor Resistance Inverse
          4. 7.3.6.2.4 Motor Resistance Inverse Scale
          5. 7.3.6.2.5 KMC Scaling Factor
          6. 7.3.6.2.6 KMC
          7. 7.3.6.2.7 VSNS_SEL
        3. 7.3.6.3 Soft-Start and Soft-Stop
          1. 7.3.6.3.1 TINRUSH
      7. 7.3.7 Protection Circuits
        1. 7.3.7.1 Overcurrent Protection (OCP)
        2. 7.3.7.2 Thermal Shutdown (TSD)
        3. 7.3.7.3 VCC Undervoltage Lockout (UVLO)
        4. 7.3.7.4 Overvoltage Protection (OVP)
        5. 7.3.7.5 nFAULT Output
    4. 7.4 Device Functional Modes
      1. 7.4.1 Active Mode
      2. 7.4.2 Low-Power Sleep Mode
      3. 7.4.3 Fault Mode
    5. 7.5 Programming
      1. 7.5.1 I2C Communication
        1. 7.5.1.1 I2C Write
        2. 7.5.1.2 I2C Read
  9. 8 Register Map
    1. 8.1 DRV8215_STATUS Registers
    2. 8.2 DRV8215_CONFIG Registers
    3. 8.3 DRV8215_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 Motor Speed and Voltage Regulation Application
        1. 9.2.3.1 Tuning 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
      4. 9.2.4 Motor Voltage
      5. 9.2.5 Motor Current
    3. 9.3 Power Supply Recommendations
      1. 9.3.1 Bulk Capacitance
    4. 9.4 Layout
      1. 9.4.1 Layout Guidelines
  11. 10Device and Documentation Support
    1. 10.1 Receiving Notification of Documentation Updates
    2. 10.2 Support Resources
    3. 10.3 Trademarks
    4. 10.4 Electrostatic Discharge Caution
    5. 10.5 Glossary
  12. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information
7.3.6.2.1 Speed and Voltage Set

Denoted by WSET_VSET, this parameter helps set the target speed or voltage, based on the REG_CTRL register setting.

When REG_CTRL is set to 10b, the speed regulation mode is enabled. WSET_VSET is an 8-bit register and can be set to a value between 00h (corresponds to 0 rad/s) and FFh (corresponds to the maximum speed allowable by W_SCALE). The speed control loop matches the value of the SPEED register to the target speed set by WSET_VSET. Please note that the maximum value of the SPEED register is 255.

When REG_CTRL is set to 11b, the motor voltage regulation mode is enabled. VM_GAIN_SEL is used to select the voltage range for a smaller or larger range of voltages.

Table 7-15 VM_GAIN_SEL Settings
VM_GAIN_SELVoltage rangeCorresponding WSET_VSET rangeApproximate WSET_VSET ResolutionFormula for WSET_VSET setting
0b0V - 15.7V

0V: 0

15.7V: 255

61.56mV/bitWSET_VSET = Target Output Voltage x (255/15.7)
1b0V - 3.92V

0V: 0

3.92V: 255

15.38mV/bit WSET_VSET = Target Output Voltage x (255/3.92)

As mentioned in Table 7-15 setting VM_GAIN_SEL to 1b allows the user to increase the resolution for voltage regulation at lower voltages.

When set to 0b, the motor voltage can be set to a value between 0 for 0V and 255 for approximately 15.7V drive output voltage. Please note that the maximum value of WSET_VSET is 255. Each bit corresponds to approximately a 61.56mV resolution of the output voltage setting. Setting WSET_VSET to 255 sets the target voltage to 15.7V. The formula to calculate the decimal value is represented by the equation:

Equation 4. Register Setting Value=Desired Target Voltage×25515.7 

For example, if desired target voltage is 5V, Register Setting Value = 5*(255/15.7) = 81. Hence, setting a value of 81 (or 51h) outputs approximately 5V.

Note:
  1. In practice, the driver's Over Voltage Protection shuts the device down before 15.7V.
  2. The maximum voltage for VM under Section 6.3 is 11V.
    1. Recommended to set the target voltage below 11V for better accuracy.
  3. To set the target voltage to 11V, set WSET_VSET to 179.