The A4983 is a complete microstep motor driver with a built-in converter for easy operation. It operates bipolar stepper motors in full, half, 1/4, 1/8, and 1/16 step modes with output drive performance up to 35 V and ±2 amps. The A4983 includes a fixed shutdown time current regulator that operates in slow or mixed attenuation mode.
The converter is key to the ease of implementation of the A4983. 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 A4983 interface is ideal for applications where complex microprocessors are unavailable or overloaded.
The chopper control within the A4983 automatically selects the current decay mode (slow or mixed). When a signal appears at the Step input pin, the A4983 determines whether that 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 generates a lower current, the current decay is set to "mixed" (the start pair of cycles reaches 31.25% of the fixed shutdown time to fast decay, then the cut-off remaining period is set to slow decay). This current decay control scheme reduces audible motor noise, increases step accuracy, and reduces power consumption.
An internal synchronous rectification control circuit reduces 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 A4983 is available in a 5 mm × 5 mm × 0.90 nominal surface-mount QFN package with an exposed heat transfer gasket (suffix ET). The package is a lead-free package (suffix –T) with a 100% matte tin plated pin frame.
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低 RDS(ON) 输出
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自驱电流衰减模式检测/选择
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混合与慢电流衰减模式
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对低功率耗散同步整流
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内部 UVLO
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交叉电流保护
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3.3 及 5 V 兼容逻辑电源
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超薄 QFN 封装
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过热关机电路