Specifications

164004.C03 J1

APPENDIX J: TP400ET ETHERNET ADAPTER BOARD

The TP400’s Ethernet chip is connected to the network’s twisted pair cable through a

small printed circuit board called the TP400ET. This is joined to the TP400 with a short

length of CAT5 unshielded twisted pair cable. The TP400ET contains the Ethernet

isolation transformer, EMC filters and an RJ45 connector with status LEDs. The

TP400ET is designed to be mounted on the enclosure; this location allows EMC

filtering to be optimised.

A cable assembly, the TB486ET-CAB, joins the TP400 to the TP400ET.

The TP400ET has two status LEDs. The green LED connects to the LED10 and

LED100 pins of the DP83815 and glows whenever the DP83815 receives valid

10Base-T or 100Base-T link pulses. The yellow LED connects to the LEDACT pin of

the DP83815 and glows when the DP83815 transmits or receives a frame.

This Appendix contains the mechanical drawing of the TP400ET, allowing users to

build their enclosure to accommodate the TP400ET. It also includes the circuit of the

TP400ET, for users who would prefer to design the TP400ET circuitry into their own

PCBs.

This circuit remains the copyright of DSP Design Limited, but DSP Design grants

permission for any or all of the circuit to be used by DSP Design customers who are

using the circuit together with DSP Design's processor boards. The circuit is offered on

an unsupported basis, and no warranty is given as to the accuracy of the design.

Care should be taken when tracking the TP400ET circuitry. The DP83815 Users’

Manual gives guidance on tracking. This is available on the Cirrus logic web site, at