SLVS855K July   2008  – March 2021 DRV8800 , DRV8801

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 Parameter Measurement Information
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagrams
    3. 8.3 Feature Description
      1. 8.3.1  Logic Inputs
      2. 8.3.2  VREG (DRV8800 Only)
      3. 8.3.3  VPROPI (DRV8801 Only)
        1. 8.3.3.1 Connecting VPROPI Output to ADC
      4. 8.3.4  Charge Pump
      5. 8.3.5  Shutdown
      6. 8.3.6  Low-Power Mode
      7. 8.3.7  Braking
      8. 8.3.8  Diagnostic Output
      9. 8.3.9  Thermal Shutdown (TSD)
      10. 8.3.10 Overcurrent Protection
      11. 8.3.11 SENSE
    4. 8.4 Device Functional Modes
      1. 8.4.1 Device Operation
        1. 8.4.1.1 Slow-Decay SR (Brake Mode)
        2. 8.4.1.2 Fast Decay With Synchronous Rectification
          1. 8.4.1.2.1 34
  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
        1. 9.2.2.1 Motor Voltage
        2. 9.2.2.2 Power Dissipation
        3. 9.2.2.3 Thermal Considerations
          1. 9.2.2.3.1 Junction-to-Ambiant Thermal Impedance (ƟJA)
        4. 9.2.2.4 Motor Current Trip Point
        5. 9.2.2.5 Sense Resistor Selection
        6. 9.2.2.6 Drive Current
      3. 9.2.3 Pulse-Width Modulating
        1. 9.2.3.1 Pulse-Width Modulating ENABLE
        2. 9.2.3.2 Pulse-Width Modulating PHASE
      4. 9.2.4 Application Curves
    3. 9.3 Parallel Configuration
      1. 9.3.1 Parallel Connections
      2. 9.3.2 Non – Parallel Connections
      3. 9.3.3 Wiring nFAULT as Wired OR
      4. 9.3.4 Electrical Considerations
        1. 9.3.4.1 Device Spacing
        2. 9.3.4.2 Recirculation Current Handling
        3. 9.3.4.3 Sense Resistor Selection
        4. 9.3.4.4 Maximum System Current
  10. 10Power Supply Recommendations
    1. 10.1 Bulk Capacitance
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Related Links
    2. 12.2 Trademarks
    3. 12.3 Electrostatic Discharge Caution
    4. 12.4 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

9.3.4.4 Maximum System Current

The idea behind placing multiple DRV8800/01 devices in parallel is to increase maximum drive current. At first glance, it may seem that the new increased ITRIP setting is given by Equation 8.

Equation 8. GUID-20201203-CA0I-WZ45-8RHT-FWZD9CFWRKWJ-low.gif

Where:

N is the number of DRV8800/01 devices connected in parallel.

ITRIP is the individual ITRIP value per device.

However, although in theory accurate, due to tolerances in internal SENSE amplifier/comparator circuitry, the system ITRIP should be expected to be less than the addition of all the individual ITRIP. The reason for this is that as soon as one of the devices senses a current for which the H Bridge should be disabled, the remaining devices will end up having to conduct the same current but with less capacity. Therefore, remaining devices are expected to get disabled shortly after.

A good rule of thumb is to expect 90% of the theoretical maximum.

By way of example, if the system level requirements indicate that 6 A of current are required to meet the motion control requirements, then:

6 A = (2.8 A x 0.9)N

N = (6 A) / (2.8 A x 0.9)

N = 2.38

In this example, three DRV8800/01 devices would be required to meet the safety needs of the system.