The A3921 is a full-bridge controller for use with N-channel power MOSFETs and is specifically designed for automotive applications that use 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 A3921 to operate when the gate driver voltage drops to 5.5 V. Bootstrap capacitors are used to provide the battery supply voltage described above required by N-channel MOSFETs. The high-end drive internal charge pump allows DC (100% duty cycle) operation.
Diodes or synchronous rectification can be used to put the entire bridge in fast or slow delay mode. In slow delay mode, current freewheeling can pass through either high-end or low-end FETs. The inductive time is adjustable via a resistor to protect the power FET from breakdown.
Integrated diagnostics indicate undervoltage, over-temperature, and power bridging faults, and can be configured to protect the power MOSFETs in most short-circuit situations.
The A3921 is available in a 28-pin TSSOP power package and is mounted with an exposed thermal pad (suffix LP). The package is lead-free and the pin frame is 100% matte tin plated.
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N 通道 MOSFET 全桥大电流门极驱动器
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高端或低端 PWM 开关
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电荷泵供低电源电压运行
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电荷泵充满后提供 100% PWM
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通过可调无感时间进行交叉传导保护
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5.5 至 50 V 电源电压范围
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集成 5 V 稳压器
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诊断输出
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低电流休眠模式