ENABLE

LMH0302

SD/HD

SDO

SDI

SDI

ENABLE

SDO

750:

75:

75:

75:

75:

SD/HD

Differential

Input

49.9:

49.9:

1.0 PF

1.0 PF

0.1 PF

4.7 PF

4.7 PF

6.8 nH

6.8 nH

0.1 PF

Copyright © 2016, Texas Instruments Incorporated

8

LMH0302

SNLS247H – APRIL 2007 – REVISED JUNE 2016

www.ti.com

Product Folder Links: LMH0302

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Copyright © 2007–2016, Texas Instruments Incorporated

8 Application and Implementation

NOTE

Information in the following applications sections is not part of the TI component

specification, and TI does not warrant its accuracy or completeness. TI’s customers are

responsible for determining suitability of components for their purposes. Customers should

validate and test their design implementation to confirm system functionality.

8.1 Application Information

The LMH0302 is a single-channel SDI cable driver that supports different application spaces. The following

sections describe the typical use cases and common implementation practices.

8.1.1 General Guidance for All Applications

The SMPTE specifications define the use of AC-coupling capacitors for transporting uncompressed serial data

streams with heavy low-frequency content. This specification requires the use of a 4.7-µF AC-coupling capacitor

to avoid low frequency DC wander. The 75-

Ω signal is also required to meet certain rise and fall timing to

facilitate highest eye opening for the receiving device.

SMPTE specifies the requirements for the Serial Digital Interface to transport digital video at SD, HD, 3 Gbps,

and higher data rates over coaxial cables. One of the requirements is meeting the required return loss. This

requirement specifies how closely the port resembles 75-

Ω impedance across a specified frequency band.

Output return loss is dependent on board design. The LMH0302 supports these requirements.

8.2 Typical Application

Figure 3. Application Circuit