SLVAE49C April   2019  – April 2022 DRV8847 , DRV8873-Q1 , DRV8904-Q1 , DRV8906-Q1 , DRV8908-Q1 , DRV8910-Q1 , DRV8912-Q1

 

  1. 1Open Load Detection in Motor Drivers
    1.     Trademarks
  2. 1Introduction
    1. 1.1 Load Connected to Supply
    2. 1.2 Load Connected to Ground (GND)
    3. 1.3 Load Connected to H-Bridge
  3. 2Passive Open Load Detection
    1. 2.1 Circuit Operation and Detection
      1. 2.1.1 H-Bridge Open
      2. 2.1.2 H-Bridge Short
      3. 2.1.3 Load Connected in H-Bridge
    2. 2.2 Circuit Operation and Detection in DRV824x
  4. 3Active Open Load Detection
    1. 3.1 Circuit Operation and Detection
  5. 4Low-Current Active Open Load Detection
  6. 5Negative-Current Active Open Load Detection
  7. 6Summary
  8. 7References
  9. 8Revision History

1.1 Load Connected to Supply

In this configuration, the unidirectional motor or solenoid / relay load is connected between an output (for example OUT1) and the supply (for example VM) as shown in Figure 1-1 (Passive OLD) and Figure 1-2 (Active OLD). This configuration is used for unidirectional control of loads. During the passive OLD, there is no current flow to the load. During the active OLD, the load's current flows from VM to OUT1 to GND when the low-side FET is turned ON.

GUID-7E142707-EE08-4588-BDCE-40BDFB20A011-low.gifFigure 1-1 Passive OLD for Load Connected to VM
GUID-F40F2CC8-7488-4DE4-911F-EDF470CD9B99-low.gifFigure 1-2 Active OLD for Load Connected to VM