Technical description

Copperhead

ECL level NRZ data signal from the available fibre channel (or Gigabit Ethernet) silicon.

The signal is then converted to drive level, pre-conditioned with an output filter, and

transmitted over the cable through an interfacing wideband pulse transformer.

The transformer converts the signal to current and voltage levels, with exceptionally

low transmit jitter, suitable for transmission on STP, twinax or coaxial cable. The trans-

ceiver matches the impedance of both the ECL circuit and the cable plant, providing a

resultant output signal with minimum jitter and return loss.

The receiver portion of the transceiver LIM takes the signal from the media cable

and equalizes it by using a unique wideband pulse transformer and circuitry. This initi-

ates the conversion process of reducing the composite signal to ECL level NRZ for the

next level fibre channel silicon.

Benefits of transformer coupling

The pulse transformers used in Copperhead

and optimum damping of transients. They also eliminate DC components in the signal

and provide common mode signal rejection. The transformer is also used to match the

load to the source and provide maximum power transfer, and also to prevent reflections

from transmission line effects.

(Figure 1) Actual oscilloscope tracing of 1.0625

Gb/s unequalized input to receiver pins 13 and

14 after transmission over 30 meters of twinax

cable.

(Figure 2) Tracing of the same signal after

equalization. Receiver output measured at pins

2 and 3.

BEFORE

(unequalized)

AFTER

(equalized for Fibre Channel)

TWO PEARL BUCK COURT

BRISTOL, PA 19007-6812

TEL 215-781-6400

FAX 215-781-6403

www.pulsespecialty.com

Fibre Channel Module — 2