SLVSHN2 July   2024 DRV8962-Q1

PRODUCTION DATA  

  1.   1
  2. 1Features
  3. 2Applications
  4. 3Description
  5. 4Pin Configuration and Functions
  6. 5Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 Typical Characteristics
  7. 6Detailed Description
    1. 6.1  Overview
    2. 6.2  Functional Block Diagram
    3. 6.3  Feature Description
    4. 6.4  Independent Half-bridge Operation
    5. 6.5  Current Sensing and Regulation
      1. 6.5.1 Current Sensing and Feedback
      2. 6.5.2 Current Sensing with External Resistor
      3. 6.5.3 Current Regulation
    6. 6.6  Charge Pump
    7. 6.7  Linear Voltage Regulator
    8. 6.8  VCC Voltage Supply
    9. 6.9  Logic Level Pin Diagram
    10. 6.10 Protection Circuits
      1. 6.10.1 VM Undervoltage Lockout (UVLO)
      2. 6.10.2 VCP Undervoltage Lockout (CPUV)
      3. 6.10.3 Logic Supply Power on Reset (POR)
      4. 6.10.4 Overcurrent Protection (OCP)
      5. 6.10.5 Thermal Shutdown (OTSD)
      6. 6.10.6 nFAULT Output
      7. 6.10.7 Fault Condition Summary
    11. 6.11 Device Functional Modes
      1. 6.11.1 Sleep Mode
      2. 6.11.2 Operating Mode
      3. 6.11.3 nSLEEP Reset Pulse
      4. 6.11.4 Functional Modes Summary
  8. 7Application and Implementation
    1. 7.1 Application Information
      1. 7.1.1 Driving Solenoid Loads
        1. 7.1.1.1 Solenoid Driver Typical Application
        2. 7.1.1.2 Thermal Calculations
          1. 7.1.1.2.1 Power Loss Calculations
          2. 7.1.1.2.2 Junction Temperature Estimation
        3. 7.1.1.3 Application Performance Plots
      2. 7.1.2 Driving Stepper Motors
        1. 7.1.2.1 Stepper Driver Typical Application
        2. 7.1.2.2 Power Loss Calculations
        3. 7.1.2.3 Junction Temperature Estimation
      3. 7.1.3 Driving Brushed-DC Motors
        1. 7.1.3.1 Brushed-DC Driver Typical Application
        2. 7.1.3.2 Power Loss Calculation
        3. 7.1.3.3 Junction Temperature Estimation
        4. 7.1.3.4 Driving Single Brushed-DC Motor
      4. 7.1.4 Driving Thermoelectric Coolers (TEC)
      5. 7.1.5 Driving Brushless DC Motors
    2. 7.2 Package Thermal Considerations
      1. 7.2.1 Thermal Performance
        1. 7.2.1.1 Steady-State Thermal Performance
        2. 7.2.1.2 Transient Thermal Performance
      2. 7.2.2 PCB Material Recommendation
    3. 7.3 Power Supply Recommendations
      1. 7.3.1 Bulk Capacitance
      2. 7.3.2 Power Supplies
    4. 7.4 Layout
      1. 7.4.1 Layout Guidelines
      2. 7.4.2 Layout Example
  9. 8Device and Documentation Support
    1. 8.1 Related Documentation
    2. 8.2 Receiving Notification of Documentation Updates
    3. 8.3 Support Resources
    4. 8.4 Trademarks
    5. 8.5 Electrostatic Discharge Caution
    6. 8.6 Glossary
  10. 9Mechanical, Packaging, and Orderable Information
    1. 9.1 Tape and Reel Information

Package Options

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

6.5.3 Current Regulation

The current chopping threshold (ITRIP) is set through a combination of the VREF voltage (VVREF) and IPROPI output resistor (RIPROPI). This is done by comparing the voltage drop across the external RIPROPI resistor to VVREF with an internal comparator.

Equation 3. ITRIP x AIPROPI = VVREF (V) / RIPROPI (Ω)

For example, to set ITRIP at 5 A with VVREF at 3.3 V, RIPROPI has to be -

RIPROPI = VVREF / (ITRIP x AIPROPI ) = 3.3 / (5 x 212 x 10-6) = 3.09 kΩ

The internal current regulation can be disabled by tying IPROPI to GND and setting the VREF pin voltage greater than GND (if current feedback is not required). If current feedback is required and current regulation is not required, set VVREF and RIPROPI such that VIPROPI never reaches the VVREF threshold.

The DRV8962-Q1 can simultaneously drive up to four resistive or inductive loads. When an output load is connected to ground, the load current can be regulated to the ITRIP level. The PWM off-time (tOFF) is fixed at 17 μs. The fixed off-time mode allows for a simple current chopping scheme without involvement from the external controller. Fixed off-time mode will support 100% duty cycle current regulation.

Another way of controlling the load current is the cycle-by-cycle control mode, where PWM pulse width of the INx input pins have to be controlled. This allows for additional control of the current chopping scheme by the external controller.

Few scenarios of driving high-side and low-side loads are described below -

  • Resistive loads connected to ground:

The regulated current will not exceed ITRIP, as long as there is some load inductance to slow down the rate of increase of current during the blanking time. If ITRIP is higher than the (VM / RLOAD), the load current is regulated at VM / RLOAD level while INx = 1 (shown in Figure 6-3).

DRV8962-Q1 Resistive Load Connected to ground, Cycle-by-cycle controlFigure 6-3 Resistive Load Connected to ground, Cycle-by-cycle control

  • Inductive loads connected to ground:

It should be ensured that the current decays enough every cycle to prevent runaway and triggering overcurrent protection.

  • For the scenario shown in Figure 6-4, with INx = 1, the low-side MOSFET is turned on for tOFF duration after IOUT exceeds ITRIP. After tOFF, the high side MOSFET is again turned on till IOUT exceeds ITRIP again.

DRV8962-Q1 Inductive Load Connected to ground, fixed off-time current choppingFigure 6-4 Inductive Load Connected to ground, fixed off-time current chopping
If, after the tOFF time has elapsed the current is still higher than the ITRIP level, the device enforces another tOFF time period of the same duration. The OFF time extension will continue till sensed current is less than ITRIP at the end of tOFF time.

  • Loads can also be controlled using the cycle-by-cycle method. When INx = 1, the current through the load builds up; and when INx = 0, the current through the load decays. By properly choosing the duty cycle of the INx pulse, current can be regulated to a target value. Various such scenarios are shown in Figure 6-5 and Figure 6-6.

DRV8962-Q1 Inductive Load Connected to ground, Cycle-by-cycle controlFigure 6-5 Inductive Load Connected to ground, Cycle-by-cycle control

The next scenario requires INx pin duty cycle adjustment (T has to be less than TOFF) to ensure that the current does not run away.

DRV8962-Q1 Inductive Load Connected to ground, Cycle-by-cycle controlFigure 6-6 Inductive Load Connected to ground, Cycle-by-cycle control

  • Loads connected to VM:

Such loads can be controlled by controlling the INx pin pulse width: INx = 0 builds up the current, and INx = 1 decays the current, as shown in Figure 6-7 and Figure 6-8.

DRV8962-Q1 Inductive Load Connected to VM, Cycle-by-cycle controlFigure 6-7 Inductive Load Connected to VM, Cycle-by-cycle control

This scenario requires INx pin duty cycle adjustment to ensure that the current does not run away.

DRV8962-Q1 Resistive Load Connected to ground, Cycle-by-cycle controlFigure 6-8 Resistive Load Connected to ground, Cycle-by-cycle control