Brand new original import, Hong Kong spot
The A3984 is a complete microstep 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 of 35 volts and ± 2 amps. The A3984 includes a fixed downtime current regulator that can be operated in slow or mixed attenuation mode.
The converter is key to the ease of implementation of the A3984. A pulse is simply entered into the "stepper" input to drive the motor to produce microsteps. There are no phase sequence tables, high-frequency control lines, or complex interfaces in the program. The A3984 interface is ideal for applications where complex 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 generate a higher or lower current in each motor phase. If the charge is producing a higher current, set this decay mode to "Slow" attenuation. If the charge produces a lower current, the current decay is set to mixed (31.25% of the fixed downtime for the start pair of cycles is set to fast decay, then the cut-off remaining period is set to slow decay. This current degradation control scheme reduces audible motor noise, increases step accuracy, and reduces power dissipation.
An internal synchronous rectification control circuit 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-up sequencing is required.
The A3984 is available in a low-profile (1.2 mm, maximum), 24-pin TSSOP package with exposed thermal insulation panel (package LP). It is also a lead-free version (with the suffix –T) and the pin frame is 100% matte tin plated.
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小型 24 个引脚 TSSOP 封装（7.8 x 4.4 x 1.2 毫米）
与我们最接近的竞争者的 PC 主板空间的三分之一相比还要少。多种应用情况下，PC 主板空间是有限的，因此越小越好。热阻：RθJA 28C/W。
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“步进”与“方向”界面
两个控制行与竞争器件的 8、10 或更多控制行进行比较。附加的 I/O 行可加至系统成本中。不需要整流表。客户可以转换至其他的 Allegro 步进/方向界面器件，而不需要改变软件。所有应用的共用界面。
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同步整流
减少功率耗散，并无需昂贵的肖特基二极管。一般可节约 20% 的功率
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低 Ron DMOS 输出
减少功率耗散。可因较低的裸片温度上升而产生较高的平均输出电流。
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自驱慢、快速及混合衰减
改善微步精确度并减少可闻噪音，这是 Allegro 专有的特性。
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2 安培峰值输出电流
2 安培额定值比大多数竞争对手高出 0.5 安培。可靠性设计产生额外的安全优势。
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至少 10 毫安睡眠模式电流
新设计禁用时要求低电流汲取。A3983/84 的大多数双极竞争者禁用时要求 10 至 1000 倍的电流汲取。
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有竞争力的价格
A3983/84 的定价可以与任何有相同输出率的步进电动机驱动器相抗衡。