Automotive brushed DC motor driver with fault reporting
The DRV8872-Q1 device from Texas Instruments is a brushed DC (BDC) motor driver for infotainment, HUD projector adjustment, motorised shifter knobs, and piezo horn drivers. Two logic inputs control the H-bridge driver, which consists of four N-channel MOSFETs that provide bidirectional control of motors up to 3.6A peak current.
The inputs can be pulse-width modulated (PWM) to control motor speed, using a choice of current-decay modes. Setting both inputs low enters a low-power sleep mode. The DRV8872-Q1 device features integrated current regulation, based on an internal reference voltage and the voltage on the ISEN pin, which is proportional to motor current through an external sense resistor.
The ability to limit current to a known level can significantly reduce the system power requirements and bulk capacitance needed to maintain stable voltage, especially for motor startup and stall conditions.
The device is fully protected from faults and short circuits, including undervoltage lockout (UVLO), overcurrent protection (OCP), and thermal shutdown (TSD). Faults are communicated by pulling the nFAULT output low. When the fault condition is removed, the device automatically resumes normal operation.
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