Cable

Driver

Cable

Equalizer

SDI

SDI

SDO

SDO

BNC_IO

LMH0387

www.ti.com

SNLS315H – APRIL 2010 – REVISED AUGUST 2015

7 Detailed Description

7.1 Overview

The LMH0387 3 Gbps HD/SD SDI Configurable I/O Adaptive Cable Equalizer / Cable Driver provides a single

chip interface to a BNC. The same I/O pin is used both for the input and the output functions of the device,

allowing the system designer to use a BNC attached to the device as either an input or an output. The LMH0387

operates over a wide range of data rates from 125 Mbps to 2.97 Gbps and supports ST 424, ST 292, ST 344, ST

259, and DVB/ASI standards. The LMH0387 includes passive components for the return loss network –

simplifying board design and development time.

7.2 Functional Block Diagram

7.3 Feature Description

The LMH0387 can be configured either in the input mode as an equalizer to receive data over coaxial cable or in

the output mode as a cable driver to transmit data over coaxial cable. The LMH0387 requires register

programming to operate either in Input Mode (Equalizer) or Output Mode (Cable Driver).

7.3.1 Input Mode (Equalizer) Description

SPI register access is required while operating the LMH0387 in the input mode. The equalizer launch amplitude

fine tuning must be set to nominal through the SPI for correct equalizer operation. To do this, write 30h

(“00110000 binary”) to SPI register 02h. The SPI registers provide access to many other useful LMH0387

features while in the input mode. Refer to the Input Mode (Equalizer) SPI Register Access section for details.

7.3.1.1 Input Interfacing

The LMH0387 accepts a single-ended input at the BNC_IO pin. The input must be AC coupled as shown in

ground.

The LMH0387 BNC_IO input can be optimized for different launch amplitudes through the SPI (see Launch

Amplitude Optimization (Register 02h) in the Input Mode (Equalizer) SPI Register Access section).

The LMH0387 correctly handles equalizer pathological signals for standard and high definition serial digital video,

as described in ST RP 178 and RP 198, respectively.

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