The DRV8434A-Q1 is an integrated motor-driver solution for bipolar stepper motors. The device provides maximum integration by integrating two N-channel power MOSFET H-bridges, current sense resistors and regulation circuitry, and a microstepping indexer. The DRV8434A-Q1 is capable of supporting a wide supply voltage of 4.5 to 48 V. DRV8434A-Q1 provides an output current up to 4 A peak, 2.5 A full-scale, or 1.8 A root mean square (rms). The actual full-scale and rms current depends on the ambient temperature, supply voltage, and PCB thermal capability.

The device uses an integrated current-sense architecture which eliminates the need for two external power sense resistors, hence saving significant board space, BOM cost, design efforts and reduces significant power consumption. This architecture removes the power dissipated in the sense resistors by using a current mirror approach and using the internal power MOSFETs for current sensing. The current regulation set point is adjusted by the voltage at the VREF pin.

A simple STEP/DIR interface allows for an external controller to manage the direction and step rate of the stepper motor. The internal microstepping indexer can execute high-accuracy micro-stepping without requiring the external controller to manage the winding current level. The indexer is capable of full step, half step, and 1/4, 1/8, 1/16, 1/32, 1/64, 1/128, and 1/256 microstepping. High microstepping contributes to significant audible noise reduction and smooth motion. In addition to a standard half stepping mode, a noncircular half stepping mode is available for increased torque output at higher motor RPM.

The device operates with smart tune ripple control decay mode, which uses a variable off-time, ripple current control scheme to minimize distortion of the motor winding current. The device can detect a motor overload stall condition or an end-of-line travel, by detecting back-emf phase shift between rising and falling current quadrants of the motor current. Unlike conventional stall detection algorithms which require an SPI interface, it detects stall using two digital IO and one analog IO pins.

The device integrates a spread spectrum clocking feature for both the internal digital oscillator and internal charge pump. This feature minimizes the radiated emissions from the device. A low-power sleep mode is included which allows the system to save power when not actively driving the motor.