TI DRV8428PWPR

The DRV8428 is a stepper motor driver for industrial and consumer applications. The device is fully integrated, comprising two N-channel power MOSFET H-bridge drivers, a microstepping indexer, and integrated current sensing. The DRV8428 can drive up to 1A full-scale output current (depending on PCB design). The DRV8428 uses an internal current sensing architecture that eliminates the need for two external power sense resistors, reducing PCB area and system cost. The device uses an internal PWM current regulation scheme that can select between smart tune and mixed decay options. Smart tune achieves excellent current regulation performance through automatic adjustment, compensating for motor variation and aging effects while reducing audible motor noise. With a simple STEP/DIR interface, the direction and step rate of the stepper motor can be managed by an external controller. The device can be configured for different step modes ranging from full-step to 1/256 microstep. A dedicated nSLEEP pin provides a low-power sleep mode, enabling ultra-low quiescent standby current. Protection features include power supply undervoltage, overcurrent, short circuit, and overtemperature protection. Fault conditions are indicated via the EN/nFAULT pin. The DRV8428 is an integrated motor driver solution for bipolar stepper motors. The device achieves greater integration by integrating two N-channel power MOSFET H-bridges, current sense resistors and regulation circuitry, and a microstepping indexer. The DRV8428 supports a wide supply voltage range of 4.2V to 33V. The DRV8428 provides up to 1.7A peak, 1A full-scale, or 0.7A RMS output current. Actual full-scale and RMS current depend on ambient temperature, supply voltage, and PCB thermal performance. The DRV8428 uses an integrated current sensing architecture that eliminates the need for two external power sense resistors, significantly saving board space and BOM cost while reducing design effort and power dissipation. This architecture uses a current mirror approach with internal power MOSFETs for current sensing, eliminating power loss in sense resistors. The current regulation setpoint is adjusted by the voltage at the VREF pin. With a simple STEP/DIR interface, the direction and step rate of the stepper motor can be managed by an external controller. The internal microstepping indexer enables high-accuracy microstepping without requiring an external controller to manage winding current levels. The indexer supports full-step, half-step, and 1/4, 1/8, 1/16, 1/32, 1/64, 1/128, and 1/256 microstepping. High microstepping helps significantly reduce audible noise and achieve smooth motion. In addition to the standard half-step mode, a non-circular half-step mode is available to increase torque output at higher motor speeds. Stepper motor drivers need to recirculate winding current by implementing multiple types of decay modes. The DRV8428 offers a smart tune decay mode. Auto tune is an innovative decay mechanism that automatically adjusts for excellent current regulation performance regardless of voltage, motor speed, variation, and aging effects. Auto tune ripple control uses a variable off-time ripple current control scheme to minimize distortion in the motor winding current. Auto tune dynamic decay uses a fixed off-time dynamic fast decay percentage scheme to minimize motor winding current distortion while achieving minimal frequency components and significantly reducing design effort. In addition to this effortless smart tune, the DRV8428 also provides a traditional mixed decay mode. The system includes a low-power sleep mode to conserve power when the motor is not actively being driven.

• PWM microstepping motor driver
• Simple STEP/DIR interface
• Up to 1/256 microstepping indexer
• Integrated current sensing
• No sense resistors required
• ±6% full-scale current accuracy
• Smart tune decay technology and mixed decay options
• 4.2V to 33V operating supply voltage range
• RDS(ON): 1500mΩ HS + LS at 24V, 25°C
• Current capacity per bridge: 1.7A peak, 1A full-scale, 0.7A rms
• Configurable off-time PWM chopping
• 7μs, 16μs, or 32μs
• Supports 1.8V, 3.3V, 5.0V logic inputs
• Low-current sleep mode (2μA)
• Spread-spectrum clock for low EMI
• Small package and form factor
• Protection features
  • VM undervoltage lockout (UVLO)
  • Overcurrent protection (OCP)
  • Thermal shutdown (OTSD)
  • Fault status output (EN/nFAULT)

• Printers and scanners
• Stage lighting equipment
• Sewing machines
• Security and dome cameras
• Office and home automation
• Factory automation and robotics
• Medical applications