Designed for use with both analog and digital satellite receivers, this dual low-noise step-down conversion regulator (LNBR) is a monolithic linear/switching regulator designed to transmit power and interface signals to an LNB step-down converter over coaxial cable. The A8297 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 A8297 design achieves high efficiency by leveraging Allegro's® advanced BCD process. 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, a tone control pin is provided for gating control of the internally generated 22kHz tone switch.
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 up to 400 kHz.
The A8297 is available in a lead-free (Pb) package.
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整合的升压 MOSFET、电流感应和补偿
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持续提供高达 550 mA 的电流
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每通道提供高达 700 mA 的电流用于重新配置
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两个通道持续提供高达 950 mA 的总电流
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两个通道提供高达 1,100 mA 的总电流用于重新配置
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可调 LNB 输出电流限制，从 300 至 800 mA
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通过 LNB 电流限制设置升压峰值电流限制水平
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8 级可编程 LNB 输出电压 (DAC)
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带关机计时器的 LNB 过流限制器
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静态 LNB 电流限制的可靠性可启动各种载荷
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跟踪升压转换器，减少功耗
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可通过外部电容配置的 LNB 瞬变时间
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推拉 LNB 输出级保持 13-18 V 和 18-13 V 瞬变时间，即使在具有高容性载荷的情况下。
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内置 22 kHz 音调振荡器，有助于 DiSEqC™ 音调编码，甚至在无载荷时亦可实现
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无需额外的外部元件即可产生音调
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动态音调检测幅度和频率的发送/接收阈值
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广泛的保护功能：UVLO、OCP、TSD、CPOK
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Reset输入禁用 LNB 和复位控制寄存器至 0 状态，以快速加载正在减载的 2 线 I2C ™ 兼容接口
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小型低剖面 5 mm × 5 mm, 0.90 mm QFN-28 封装