原标题：NS LMH0395 3Gbps HD SDI自适应均衡方案

　　NS 公司的LMH0395 是3Gbps HD/SD SDI双输出低功耗自适应电缆均衡器，数据速率从125 Mbps 到2.97Gbps，支持SMPTE 424M, SMPTE 292M, SMPTE 344M, SMPTE 259M和DVB-ASI标准，270Mbps时Belden 1694A电缆长度达220米，Belden 1694A电缆长度达400米。双输出的功耗145 mW，单输出的功耗115 mW，主要用在SMPTE 424M, SMPTE 292M, SMPTE 344M和SMPTE 259M串行数字接口以及宽带视频路由器，交换器和分布放大器。本文介绍了LMH0395 LMH0395主要特性，以及多种应用电路。

　　3G HD/SD SDI Dual Output Low Power Extended Reach Adaptive Cable Equalizer

　　The LMH0395 3 Gbps HD/SD SDI Dual Output Low Power Extended Reach Adaptive Cable Equalizer is designed to equalize data transmitted over cable (or any media with similar dispersive loss characteristics). The equalizer operates over a wide range of data rates from 125 Mbps to 2.97 Gbps and supports SMPTE 424M, SMPTE 292M, SMPTE 344M, SMPTE 259M, and DVB-ASI standards.

　　The LMH0395 provides extended cable reach with ultra low power consumption. The equalizer includes active sensing circuitry that ensures robust performance and enhanced immunity to variations in the input signal launch amplitude. The LMH0395 offers power management to further reduce power consumption when no input signal is present.

　　The LMH0395 has two differential serial data outputs, increasing flexibility and eliminating the need for a fanout buffer on the output in many applications. The outputs may be independently enabled and controlled. The output drivers offer programmable de-emphasis for up to 40” of FR4 trace losses.

　　The LMH0395 supports two modes of operation. In pin mode, the LMH0395 operates with control pins to set its operating state. In SPI mode, an optional SPI serial interface can be used to access and configure multiple LMH0395 devices in a daisy-chain configuration. This allows programming the output common mode voltage and swing, output de-emphasis level, input launch amplitude, and power management settings, as well as access to a cable length indicator and all pin mode features.

　　LMH0395主要特性：

　　■ SMPTE 424M, SMPTE 292M, SMPTE 344M, SMPTE 259M, and DVB-ASI compliant

　　■ Equalizes up to 200 meters of Belden 1694A at 2.97 Gbps, up to 220 meters of Belden 1694A at 1.485 Gbps, or up to 400 meters of Belden 1694A at 270 Mbps

　　■ Ultra low power consumption: 145 mW (dual outputs), 115 mW (single output)

　　■ Dual differential outputs; second output can be independently powered down

　　■ Power save mode with auto sleep control (16 mW typical power consumption in power save mode)

　　■ Output de-emphasis to compensate for FR4 board trace losses

　　■ Digital and analog programmable MUTEREF threshold control

　　■ Optional SPI register access

　　■ Wide range of data rates: 125 Mbps to 2.97 Gbps

　　■ Internally terminated 100Ω LVDS outputs with programmable output common mode voltage and swing

　　■ Programmable launch amplitude optimization

　　■ Cable length indicator

　　■ Single 2.5V supply operation

　　■ 24-pin LLP package

　　■ Industrial temperature range: −40℃ to +85℃

　　LMH0395应用：

　　■ SMPTE 424M, SMPTE 292M, SMPTE 344M, and SMPTE 259M serial digital interfaces

　　■ Broadcast Video routers, switchers, and distribution Amplifiers

　　图1。LMH0395方框图(Pin 模式)

　　图2。LMH0395典型应用方框图(Pin 模式)

　　图3。LMH0395 DC输出和时钟恢复器LMH0346接口框图

　　图4。LMH0395 DC输出和时钟恢复器LMH0356接口框图

　　图5。LMH0395 SPI菊花链接系统架构图

　　图6。LMH0395 应用电路图(SPI模式)