The A4491 can power printers, office automation, industrial, and portable devices with three high-current, high-performance, switching regulator outputs in a single package, saving space, cost, and component count.
High-frequency switches support the use of low-cost inductors and small ceramic output capacitors. The regulator's on-cycle cycles are staggered to minimize stress on the input capacitor and reduce EMI. Separate "enable" pins simplify power-up sequencing and shutdown functions, and a user-configurable delayed power-up reset (POR) circuit indicates when a regulator meets specifications. In addition, when the input voltage drops below specification, a power-on reset sign is displayed to warn the system controller in advance, while the switch continues to operate until it is off.
Internal diagnostics provide comprehensive overload, input undervoltage, and overtemperature protection.
The total output current capability of the three outputs is ~4.5 A, which is determined by the Vin and the individual Vout levels.
The A4491 is available in a 20-contact, 4 mm × 4 mm, 0.75 mm nominal overall height QFN package with exposed pads for enhanced heat dissipation. It is packaged as a lead-free (Pb) product with a 100% matte tin plated pin frame.
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图片、喷墨及便携式打印机
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机顶盒
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平板计算机
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其它消费电子产品应用
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销售终端应用
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保安系统
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博弈机
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其它工业应用
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三个降压转换器整合在一个封装中
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4.5 至 23 V 输入电压范围
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550 kHz 固定频率
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多相切换，以减少元件数量和 EMI
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独立控制各个转换器的排序和关机控制
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可调整延迟的通电复位标志
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内部补偿，以最大限度减少元件和简化设计
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4 ×4 mm QFN 封装, 小型 PCB