Designed for bidirectional pulse-width modulation (PWM) current control of inductive loads, the A4973 is capable of continuously outputting up to ±1.5 amps and operating voltages up to 50 volts. An internal fixed downtime pulse-width modulation (PWM) current control circuit can be used to adjust the maximum load current to the desired value. The user can set the peak load current limit by selecting the input reference voltage and external inductive resistor. Users can set a fixed downtime pulse duration by selecting an external RC timing network. Internal circuit protection includes overheating shutdown with delay, transient suppression diodes, and crossover current protection. No special power-up sequencing is required.
While the "Enable" input is kept low, the "Phase" input controls the polarity of the load current by selecting the appropriate source to pair with the sink current driver. The Mode input determines whether the pulse-width modulation (PWM) current control circuit operates in slow current decay mode (referring only to the selected source driver switch) or in fast current decay mode (selected source and sink current switches). The user can select a blank window to prevent false triggering of the PWM current control circuit. While the "Enable" input remains high, all output drivers are disabled. Sleep mode reduces power consumption.
The brake function is enabled when the logic is low applied in the Brake input. In this way, the "on" and "phase" of the two source drivers become "off", and the two sink current drivers become "on". This brake function can be used to dynamically brake brushed DC motors.
The A4973 is available in two power packages: a 16-pin dual-in-line plastic package with a copper heatsink and a 16-pin plastic SOIC with a copper heatsink. For both packages, the power interface is at ground potential and electrical isolation is not required. Each package is lead-free and features a 100% matte tin-plated pin frame.
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±1.5 安培连续输出电流
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50 伏特输出电压额定值
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3 伏特至 5.5 伏特逻辑电源电压
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内部 PWM 电流控制
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快慢电流衰减模式
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睡眠 （低电流损耗） 模式
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内部瞬态抑制二极管
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内部过热关机电路
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交叉电流和 UVLO 保护