DRV8711DCPR

The DRV8711DCPR from Texas Instruments is a stepper motor gate driver IC that drives external N-channel MOSFETs for bipolar stepper motors or two brushed DC motors. It integrates a 1/256-step microstepping indexer for ultra-smooth motion profiles. The SPI serial interface configures output current (torque), step mode, decay mode, and stall detection parameters. Auto-mixed decay mode dynamically adjusts the current decay strategy for optimal performance across speed ranges. The stall detection feature uses back-EMF sensing to detect motor stall without external sensors, enabling sensorless homing. The internal 5V regulator can supply up to 10mA for external logic. Protection features include overcurrent protection (OCP), overtemperature shutdown (OTS), and undervoltage lockout (UVLO), with a dedicated FAULTn pin and individual fault status bits accessible via SPI.

The DRV8711DCPR operates as a microstepping chopper driver for external N-channel MOSFETs. The STEP/DIR interface accepts step pulses from the MCU; the internal indexer converts each step into the appropriate phase current targets for the two motor windings based on the configured microstep resolution (full step to 1/256). The SPI interface sets the target current via an 8-bit torque DAC and the current sense amplifier gain (5, 10, 20, or 40 V/V) for external sense resistors. The PWM chopper regulates the winding current: when the current through the sense resistor exceeds the target, the driver turns off the high-side MOSFET for a programmable off-time (0.5µs to 128µs), allowing the current to decay through the low-side MOSFET and body diode. The decay mode (fast, slow, or auto-mixed) determines whether both low-side MOSFETs are on (slow decay) or only one (fast decay) during the off-time. Auto-mixed decay uses slow decay when the current is increasing and fast decay when decreasing, minimizing distortion. Stall detection monitors the back-EMF of the motor windings; when the motor stalls, the BEMF drops to near zero, which is detected and reported on the STALLn output and via SPI status bits. The overcurrent protection monitors the voltage across each external MOSFET; if the drop exceeds the programmable threshold (250mV to 1000mV), all outputs are disabled and the fault is latched.

• 3D Printers: 1/256 microstepping produces near-silent stepper operation; SPI tunes torque for different print speeds
• CNC Machines: External MOSFETs scale to 10A+ per phase for high-torque NEMA 34 steppers; stall detection for homing
• Sensorless Homing: BEMF stall detection eliminates limit switches, reducing wiring and mechanical complexity
• Industrial Drives: Auto-mixed decay minimizes current distortion across the full speed range without manual tuning
• Robotics: SPI interface enables real-time torque adjustment for compliance and force control algorithms

DRV8711DCPR is a 52V stepper motor gate driver from TI in HTSSOP-38 with 1/256 microstepping. The DRV8711EVM evaluation module enables rapid prototyping. The TMC5130 from Trinamic offers integrated MOSFETs with 1/256 stepping and sensorless homing in QFN-48. The DRV8825 provides integrated 2.5A drivers in HTSSOP-28 for simpler designs. The L6470 from ST provides 7A gate driver with 1/128 microstepping. The A5995 from Allegro offers dual H-bridge gate driver in TSSOP-28. For brushed DC, DRV8701 provides single H-bridge gate driver.