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Design Guidelines for 78P235x E4/STM1e LIUs

PCB layout and hardware design guidelines for Teridian 78P235x STM1e/E4 Line Interface Units, covering terminations, grounding, transformer selection, and surge protection.

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Overview

This application note provides comprehensive design and layout guidelines for the Teridian 78P235x series of STM1e/E4 Line Interface Units (LIUs), including the 78P2351, 78P2351R, and 78P2352. It details best practices for PCB grounding using split component and frame ground planes, power plane decoupling, and differential trace routing for CMI and LVPECL signals. The document specifies I/O termination circuits for transmitters and receivers, recommendations for 1:1CT wideband transformers from vendors like Mini-Circuits, Halo, and Tamura, and supplemental surge protection for ITU K.41 compliance. It also includes crystal oscillator requirements and thermal management advice for enhanced LQFP packages.

Use Cases

  • Designing telecommunication line cards
  • Implementing STM1e/E4 interfaces
  • Optimizing signal integrity for high-speed LIUs
  • Selecting compatible transformers and oscillators for 78P235x designs

Topics

78P2351
78P2352
STM1e
E4
LIU
Line Interface Unit
PCB Layout
CMI
LVPECL
Transformer Selection
Surge Protection
Teridian

Referenced Parts

CB3LV-3C-19.440000

CTS Corporation

CTS CB3LV-3C-19.440000

C3392-19.44MHz

Crystek Corporation

Crystek C3392-19.44MHz

SM78809

Datatronics

Datatronic SM78809

EH2645ETTS-19.440M

Ecliptek

Ecliptek EH2645ETTS-19.440M

TG04-TDK1N1

Halo Electronics

Halo TG04-TDK1N1

TG04-TDK2NS

Halo Electronics

Halo TG04-TDK2NS

000-7419-30R-LF1

Midcom

Midcom 000-7419-30R-LF1

7400-30R-LF1

Midcom

Midcom 7400-30R-LF1

S1613B-19.44

SaRonix

SaRonix S1613B-19.44

TTC-298

Tamura Corporation

Tamura TTC-298

TTC-300

Tamura Corporation

TAMURA TTC-300

78P2351

Teridian Semiconductor

78P2351 Single Channel LIU

78P2351R

Teridian Semiconductor

78P2351R Small form factor LIU

78P2352

Teridian Semiconductor

78P2352 Dual Channel LIU

TXC-03456

Transwitch

Transwitch L4M TXC-03456 E4 Mapper

1N1

TDK

Halo TG04-TDK1N1

2NS

TDK

Halo TG04-TDK2NS

78P2351

TDK

TDK 78P2351

TG04-

TDK

Halo TG04-TDK1N1

TG04-

TDK

Halo TG04-TDK2NS