DESCRIPTIONTB6560 3A Single Axis Stepper Stepping Motor Driver Board will significantly increase torque and ease of configuration of larger motors. Cheap and great driver for CNC or 3D printer.Ultra-small, the overall size: 62mm * 75mm, installation of four mechanical positioning hole size: 65mm * 55, hole size Φ3mmProduct Parameters* Rated voltage: DC 12V-24V* Maximum current: 3.5A* Current adjustable (Current Settings): 0.5A, 1A, 1.5A, 1.8A, 2A.2.5A, 3.5A* Subdivision adjustable (Excitation Mode): 1,2,8,16FEATURE the current level adjustable to meet your various application needs. the Automatic half-decay adjustable. 6N137 high-speed optical coupling, to ensure a high speed not step out. thick tooth radiators, good heat dissipation. Attenuation adjustable (Decay Mode)0 %—- no decay mode— 25% of the slow decay mode— 50% of the normal mode100% – Fast Decay mode—– Decay mode of regulation by different motors to match impedance, thereby eliminating the noise when locked stepper motor and motor movement in the shake.Automatic half current setting (Torque Settings)%—- No pulse when the current 20 to normal operating current of 20%50 %—- no pulse current 50% to normal operating current75 %—- no pulse current 75% to normal operating current100% — no pulse when the current 100% to normal operating current