A8282
LNB 电源和控制稳压器

特点

• LNB 选择和备用功能
• 内置音调振荡器出厂校准到 22 kHz，有助于
• DiSEqC^TM（EUTELSAT 的商标）编码
• 耗散跟踪开关模式电源转换器
• 外部调整短路保护
• LNB 短路保护和诊断
• 辅助调制输入
• 电缆长度补偿（仅用于 A8282SLB）
• 内部过温保护
• 反向电流保护

描述

设计用于模拟和数字卫星接收器，这些低噪音降频转换稳压器 (LNBR) 是单芯片线性开关稳压器，专门设计用于通过同轴电缆将功率和接口信号传给 LNB 降压转换器。如果该器件处于备用模式（EN 端子低），将会禁用稳压器输出，从而允许共用相同同轴电缆的其它卫星接收器提供或控制天线降压转换器。在该模式下，器件会限制输出反向电流。

使用 VSEL 端子将 A8281SLB 输出设置为 13 或 18-V。它采用内部装有保险丝引脚（用于增强热耗散）的 16 引脚 SOIC 封装。该装有保险丝的引脚已经接地，因此不需要电气绝缘。

使用 VSEL 端子将 A8282SLB 输出设置为 12、13、18 或 20-V。另外，有可能按 1-V 的幅度增加所选电压，以补偿同轴电缆中的电压降（LLC 端子高）。它采用内部装有保险丝引脚（用于增强热耗散）的 24 引脚 SOIC 封装。配有熔断器的引线处于接地电位，无须电气隔离。A8282SLB 是 A8283SLB 的改进版本，并无旁路开关。该无铅版本的引脚框采用 100% 雾锡电镀。

功能方框图

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A8282
LNB Supply and Control Voltage Regulator

Features

• LNB Selection and Standby function
• Built-In Tone Oscillator Factory Trimmed to 22 kHz, Facilitates
• DiSEqC^TM (a trademark of EUTELSAT) Encoding
• Tracking Switch-Mode Power Converter for Lowest Dissipation
• Externally Adjustable Short-Circuit Protection
• LNB Short-Circuit Protection and Diagnostics
• Auxiliary Modulation Input
• Cable Length Compensation (A8282SLB only)
• Internal Over-Temperature Protection
• Reverse-Current protection

Description

Intended for analog and digital satellite receivers, these low-noise block converter regulators (LNBRs) are monolithic linear and switching voltage regulators specifically designed to provide the power and interface signals to the LNB down converter via the coaxial cable. If the device is in standby mode (EN terminal low), the regulator output is disabled, allowing the antenna down converters to be supplied or controlled by other satellite receivers sharing the same coaxial cable. In this mode, the device will limit the output reverse current.

The A8282SLB output is set to 12, 13, 18, or 20-V by the VSEL terminals. Additionally, it is possible to increase the selected voltage by 1-V to compensate for the voltage drop in the coaxial cable (LLC terminal high). It is supplied in a 24-lead SOIC package with internallyfused leads for enhanced thermal dissipation. The fused leads are at ground potential and need no electrical isolation The A8282SLB is an improved version of the A8283SLB, without a bypass switch.The lead (Pb) free version has 100 % matte tin leadframe plating.

Functional Block Diagram