The A3982 is a complete oneStepper motor driver, with a built-in converter for easy operation. It operates bipolar stepper motors in full and half-step mode with output drive performance up to 35 V and ±2 A. The A3982 includes a fixed off-time current regulator, the Voltage regulatorCan operate in slow or mixed attenuation mode.
The converter is key to the A3982's ease of implementation. Simply enter a pulse into the "step" input to drive the motor to generate a step. There are no phase order tables, high-frequency control lines, or complex interfaces in this program. The A3982 interface is ideal for complex applications where the microprocessor is unavailable or overloaded.
The chopper control within the A3982 automatically selects the current decay mode (slow or mixed). When a signal appears at the Step input pin, the A3982 determines whether the step will produce a higher or lower current in each motor phase. If the charge generates a higher current, set this decay mode to "slow" decay. If the charge produces a lower current, the current decay is set to mixed (start with fast decay for cycles reaching 31.25% of fixed downtime, then set to slow decay until the remaining period. This current attenuation control scheme reduces audible motor noise, increases step accuracy, and reduces power dissipation.
Internal synchronous rectification control circuitry is used to improve power consumption during pulse-width modulation (PWM) operation.
Internal circuit protection includes thermal shutdown due to hysteresis, undervoltage lockout (UVLO), and crossover current protection. No special power-on sequencing is required.
The A3982 is available in a 24-pin wide-body SOIC (Package LB) package with a power ground pin with a fuse inside. The packages are lead-free and feature 100% matte tin plating.
- Low RDS (ON) output
- Automatic detection/selection of current decay mode
- Mixed with slow current attenuation modes
- Synchronous rectification for low power dissipation
- Internal undervoltage lockout (UVLO) and thermal shutdown circuitry
- Crossover current protection