全新原装进口，香港现货
The A3984 is a full Microstepping motor driver, with a built-in converter for easy operation. It operates bipolar stepper motors in full, 1/2, 1/4 and 1/16 step modes with an output drive performance of 35 volts and ± 2 amps. The A3984 includes a fixed downtime current regulator that can operate in slow or mixed decay mode.
The converter is key to the A3984's ease of implementation. Simply enter a pulse into the "step" input to drive the motor to generate microsteps. There are no phase order tables, high-frequency control lines, or complex interfaces in this program. The A3984 interface is ideal for complex applications where microprocessors are unavailable or overloaded.
The chopper control within the A3984 automatically selects the current decay mode (slow or mixed). When a signal appears at the Step input pin, the A3984 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 A3984 is available in a low profile (1.2 mm, max) 24-pin TSSOP package with exposed heat shield (package LP). It is also Pb-free (suffix –T) and has 100% matte tin leadframe plating.
- Small 24-pin TSSOP package (7.8 x 4.4 x 1.2 mm)
That's less than a third of the PC motherboard space of our closest competitor. PC motherboard space is limited in many applications, so smaller is better. Thermal resistance: RθJA28C/W。
- Step and Direction interfaces
The two control lines are compared to 8, 10, or more control lines of competing devices. Additional I/O lines can be added to the system cost. Rectifier tables are not required. Customers can switch to other Allegro stepping/direction interface devices without software changes. A common interface for all apps.
- Synchronous rectification
Reduces power dissipation and eliminates the need for expensive Schottky diodes. Typical power savings of 20%.
- Low RonDMOS output
Reduced power dissipation. Higher average output current can be generated due to lower die temperature rises.
- Self-driving slow, fast and mixed attenuation
Improved microstep accuracy and reduced audible noise are proprietary to Allegro.
- 2 amps peak output current
The 2 amp rating is 0.5 amps higher than most competitors. Reliability design yields additional safety benefits.
- At least 10 mA sleep mode current
New designs require low current sinking when disabled. Most bipolar competitors for the A3983/84 require 10 to 1000x current draw when disabled.
- Competitive price
The pricing of the A3983/84 can compete with any stepper motor driver with the same output rate.