Migrating from the LAN83C180 10/100 PHY to the LAN83C185 10/100 PHY

SMSC AN 10.13

Page 3

Revision 1.2 (07-12-04)

APPLICATION NOTE

1

General Description

This application note discusses how to migrate from an existing design using the SMSC LAN83C180 PHY to

SMSC’s next generation LAN83C185 PHY. A general overview is provided which includes such topics as

power connections, magnetics interface, proper signal termination, clock circuit implementation and pinout

differences.

1.1

Overview

This application note provides a summary of the recommendations and requirements for migrating from a

SMSC LAN83C180 10/100 PHY design to a new design incorporating the LAN83C185 10/100 PHY. This

document references additional documentation and schematics (see section 1.2 “Reference Documents”).

This document also uses the original “LAN83C180 10/100 Adapter Reference Design” as a reference for all

LAN83C180 vs. LAN83C185 discussions.

Please note that since each customer’s LAN83C180 design may differ, the contents below are offered as a

general guideline. Specific customer requirements may force the guidelines discussed here to be adjusted

or ignored.

1.2

Reference Documents

The following documents are referred to in this application note:

SMSC LAN83C185 datasheet

SMSC LAN83C185 MII Customer PCB (Assy. 6316 Rev. A2) Schematic

SMSC LAN83C180 10/100 PHY Adapter Reference Design (Assy. 6096 Rev. A1) Schematic

SMSC Application Note AN 8.13 - “Suggested Magnetics”

SMSC Application Note AN 10.7 - “Parallel Crystal Circuit Input Voltage Control”

Please note that it is important to always refer to the SMSC LAN83C185 datasheet and the LAN83C185 MII

Customer Reference Design Schematic for complete and current information regarding LAN83C185

designs. Additionally, the circuit examples shown in this document are for illustrative purposes only. Please

reference the LAN83C185 MII Customer Reference Design Schematic when implementing actual circuits in

your design.

Please visit SMSC’s website at http://www.smsc.com/ for the latest updated documentation.