Designed for use with analog and digital satellite receivers, this single-channel low-noise step-down conversion regulator (LNBR) is a monolithic linear/switching regulator designed to transmit power and interface signals to an LNB buck converter over coaxial cable. The A8294 features a boost switch and compensation circuitry integrated into the device with only a small number of external components. Choose a higher switching frequency to minimize the size of the passive filter element and further reduce costs. The high level of component integration ensures extremely low noise and pulsating graphics.
The A8294 is designed to achieve high efficiency by leveraging Allegro's® advanced BCD processes. Optimized for integrated boost switches to minimize switching and static losses. To further improve efficiency, voltage drops in the process of tracking regulators have been eliminated to a minimum.
For DiSEqC™ communication, several modes are available to generate a tone signal throughout the process until there is no load, using an internal or external clock source.
The device provides a comprehensive set of fault registers that meet all common standards, including: overcurrent, overtemperature shutdown, undervoltage, and poor power supply.
The device uses a 2-wire bidirectional serial interface, is compatible with the I2C™ standard, and operates at frequencies up to 400 kHz.
The A8294 is available in a lead-free (Pb) MLP/QFN package, ES, 20 contacts, 4 mm × 4 mm, 0.75 nominal overall height.
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双线 I2C™ 兼容接口：控制（写入）和状态（读取）
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兼容所有通用标准的 LNB 电压（6 个编程等级）
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追踪开关模式功率转换器，实现最低耗散
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集成转换器开关和电流感应
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提供高达 700 mA 连续负载电流
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最低 800 mA 的输出电流限制，配备 48 ms 计时器r
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静态电流限制电路允许在启动时就达到满电流和实现 13→18 V 输出转换；可靠地启动宽负载范围
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推挽输出级可最小化 13→18 V 和 18→13 V 输出转换时间，实现较高的电容负载
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可通过外置计时电容器调整升/降时间
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内置音频振荡器，在出厂时已校正至 22 kHz，促进
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DiSEqC™ 音频编码，即使没有负载也是如此
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两种 22 kHz 音频生成方法，包括拨出音频验证 (TDET)
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辅助调制输入
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配备计时器的 LNB 过电流
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输出电压电平、输入电源欠压锁定和 DiSEqCTM 音频输出的诊断