The A3981 is a programmable microstep motor driver with a built-in converter for easy operation. It is a single-chip solution capable of driving bipolar stepper motors in full-step, half-step, quarter, and sixteenth-step modes with operating voltages and currents up to 28 V and ±750 mA. The A3981 can be controlled using simple step and direction inputs or via an SPI-compatible interface, and can also be used to set up a variety of integration functions and read diagnostic information.
The current regulator is programmed to operate with fixed downtime or fixed frequency PWM and can reduce the motor's audible noise and improve step accuracy with multiple attenuation modes. Moreover, phase ammeters can be programmed through serial interfaces to establish appropriate microstep current distributions for specific applications, further improving motor performance.
All phase currents of the motor are controlled via a DMOS fully bridged unit, using synchronous rectification to reduce power dissipation. When switching between high-side and low-side drives, internal circuitry and timers prevent transconductivity and breakdown,
Thus avoiding output short circuits. In addition, it features low load current and stall rotor detection. Chip-level protection includes: high and low temperature warnings, over-temperature shutdown, over-voltage and under-voltage lockout.
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汽车步进电动机
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引擎管理
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车头灯定位
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典型应用 ±750 mA、28 V
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低 RDS (On)输出，一般为 0.5 Ω源极和灌电流
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自动电流衰减模式检测/选择
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混合、快、慢电流衰减模式
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同步整流，减少功率耗散
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内部过压锁定（OVLO）、欠压锁定 (UVLO) 与过热关机电路
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交叉电流保护
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短路和断路诊断
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高温和低温警告
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失速检测功能
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SPI 兼容型或简单的步进和方向运动控制
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通过 SPI 兼容型串行接口提高可配置性