The A4957 is a full-bridge controller for use with an external N-channel power MOSFET and is specifically designed for applications using high-power inductive loads such as DC brush motors.
The unique charge-pumped regulator provides a complete (>10 V) gate driver to handle battery voltages as low as 7 V and allows the A4957 to operate when the gate driver voltage drops to 4.5 V.
Bootstrap capacitors are used to provide the battery supply voltage described above required by N-channel MOSFETs. The unique bootstrap charge management system ensures that bootstrap capacitors are always fully charged to supply high-end gate driver circuitry.
The user-configured no-inductive time of the external resistor independently controls the individual power MOSFETs and protects them from breakdown.
Integrated diagnostics indicate undervoltage and overtemperature faults.
The A4957 is available in a 24-contact 4 mm × 4 mm × 0.75 mm QFN package with exposed pads for enhanced heat dissipation. They are all lead-free and 100% matte tin plated (suffix –T).
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N 通道 MOSFET 全桥式高电流门极驱动器
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独立控制每个 MOSFET
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用于低电源电压下运行的电荷泵
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带可调无感时间的交叉传导保护
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电源电压范围为 4.5 至 50 V
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诊断性输出
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低电流睡眠模式