SLVA959B November   2018  – October 2021 DRV10866 , DRV10963 , DRV10964 , DRV10970 , DRV10974 , DRV10975 , DRV10983 , DRV10983-Q1 , DRV10987 , DRV11873 , DRV3205-Q1 , DRV3220-Q1 , DRV3245E-Q1 , DRV3245Q-Q1 , DRV8301 , DRV8302 , DRV8303 , DRV8304 , DRV8305 , DRV8305-Q1 , DRV8306 , DRV8307 , DRV8308 , DRV8312 , DRV8313 , DRV8320 , DRV8320R , DRV8323 , DRV8323R , DRV8332 , DRV8343-Q1 , DRV8350 , DRV8350R , DRV8353 , DRV8353R , DRV8412 , DRV8701 , DRV8702-Q1 , DRV8702D-Q1 , DRV8703-Q1 , DRV8703D-Q1 , DRV8704 , DRV8711 , DRV8800 , DRV8801 , DRV8801-Q1 , DRV8801A-Q1 , DRV8802 , DRV8802-Q1 , DRV8803 , DRV8804 , DRV8805 , DRV8806 , DRV8811 , DRV8812 , DRV8813 , DRV8814 , DRV8816 , DRV8818 , DRV8821 , DRV8823 , DRV8823-Q1 , DRV8824 , DRV8824-Q1 , DRV8825 , DRV8828 , DRV8829 , DRV8830 , DRV8832 , DRV8832-Q1 , DRV8833 , DRV8833C , DRV8834 , DRV8835 , DRV8836 , DRV8837 , DRV8837C , DRV8838 , DRV8839 , DRV8840 , DRV8841 , DRV8842 , DRV8843 , DRV8844 , DRV8846 , DRV8847 , DRV8848 , DRV8850 , DRV8860 , DRV8870 , DRV8871 , DRV8871-Q1 , DRV8872 , DRV8872-Q1 , DRV8873-Q1 , DRV8880 , DRV8881 , DRV8884 , DRV8885 , DRV8886 , DRV8886AT , DRV8889-Q1

 

  1.   Trademarks
  2. 1Grounding Optimization
    1. 1.1 Frequently Used Terms/Connections
    2. 1.2 Using a Ground Plane
      1. 1.2.1 Two-Layer Board Techniques
    3. 1.3 Common Problems
      1. 1.3.1 Capacitive and Inductive Coupling
      2. 1.3.2 Common and Differential Noise
    4. 1.4 EMC Considerations
  3. 2Thermal Overview
    1. 2.1 PCB Conduction and Convection
    2. 2.2 Continuous Top-Layer Thermal Pad
    3. 2.3 Copper Thickness
    4. 2.4 Thermal Via Connections
    5. 2.5 Thermal Via Width
    6. 2.6 Summary of Thermal Design
  4. 3Vias
    1. 3.1 Via Current Capacity
    2. 3.2 Via Layout Recommendations
      1. 3.2.1 Multi-Via Layout
      2. 3.2.2 Via Placement
  5. 4General Routing Techniques
  6. 5Bulk and Bypass Capacitor Placement
    1. 5.1 Bulk Capacitor Placement
    2. 5.2 Charge Pump Capacitor
    3. 5.3 Bypass/Decoupling Capacitor Placement
      1. 5.3.1 Near Power Supply
      2. 5.3.2 Near Power Stage
      3. 5.3.3 Near Switch Current Source
      4. 5.3.4 Near Current Sense Amplifiers
      5. 5.3.5 Near Voltage Regulators
  7. 6MOSFET Placement and Power Stage Routing
    1. 6.1 Common Power MOSFET Packages
      1. 6.1.1 DPAK
      2. 6.1.2 D2PAK
      3. 6.1.3 TO-220
      4. 6.1.4 8-Pin SON
    2. 6.2 MOSFET Layout Configurations
    3. 6.3 Power Stage Layout Design
      1. 6.3.1 Switch Node
      2. 6.3.2 High-Current Loop Paths
      3. 6.3.3 VDRAIN Sense Pin
  8. 7Current Sense Amplifier Routing
    1. 7.1 Single High-Side Current Shunt
    2. 7.2 Single Low-Side Current Shunt
    3. 7.3 Two-Phase and Three-Phase Current Shunt Amplifiers
    4. 7.4 Component Selection
    5. 7.5 Placement
    6. 7.6 Routing
    7. 7.7 Useful Tools (Net Ties and Differential Pairs)
    8. 7.8 Input and Output Filters
    9. 7.9 Do's and Don'ts
  9. 8References
  10. 9Revision History

7 Current Sense Amplifier Routing

Included with TI’s wide range of motor drivers are devices that feature built-in current sensing, most of which use an external shunt resistor as the measurement source. Including the current sense amplifier with the driver provides an all-in-one solution for the motor interface, and it allows higher-quality current sensing at a lower cost. Figure 7-1 shows all the current sense topologies available.

GUID-83DB4A40-9D66-4DA1-B5C0-662C7BC3BC6E-low.gifFigure 7-1 Current Sense Topologies

The integrated current sense amplifiers (CSAs) built into these devices typically fall into three categories, each with their benefits. These categories are described in the following sections.