RJ45 connector with 1000 baseT / gigabit ethernet

Posted on Thursday, August 16th, 2007

I had a technical inquiry from a customer in Thailand today, and wanted to share the discussion with you... The customer has a circuit design that includes a PHY chip (physical layer transceiver) for 1000 BaseT, or gigabit ethernet, and he wanted to make the connection to the outside world and was asking how to do this. I told him he had the following two options...
1. "Discrete" components. In this scenario, the customer could use a gigabit transformer (for impedance matching) along with a passive RJ 45 jack. Specifically, i recommend the S558-5999-P3-F transformer from Bel Fuse Inc (about $2.53 for 500 pcs.) We find that this part works best with 1000 BaseT tranceivers from Broadcom. Or, if the design is using Marvel PHY, i'd recommend the S558-5999-M8-F transformer from Bel Fuse Inc (about $1.81 for 500 pcs.) In conjuction with this, we recommend the SS-60300-010 connector from Stewart(about $1.67 for 500 pcs.) See links:

http://arcadiansales.com/belbel-fusestewart-connector/discrete-magnetics-for-lan-ethernet-or-telecom/S5585999P3F/
http://arcadiansales.com/searchbypartnumber_details.php?part_number=S5585999M8F
http://arcadiansales.com/searchbypartnumber_details.php?part_number=SS60300010

2. The second way to attack this design is with MagJack (integrated connector modules) from BEL (Bel Fuse - Stewart Connector.) The MagJacks include an RJ45 connector, 10/100/1000 baseT magnetics, (4) 75 ohm resistors, a 1000pf / 2Kv capacitor and LED indicators for link and activity. If you choose this solution, i would recommend using the Bel Fuse 0826-1X1T-23-F (about $3.75 for 500 pcs) for Broadcom based designs, or the 0826-1K1T-43-F (about $3.37 for 500 pcs)for Marvell based designs. Both links are below.

http://arcadiansales.com/belbel-fusestewart-connector/rj45-connector-with-ethernet-andor-poe---poeplus/08261X1T23F/
http://arcadiansales.com/belbel-fusestewart-connector/rj45-connector-with-ethernet-andor-poe---poeplus/08261K1T43F/

Keep in mind that all of these devices are in stock and available at www.arcadiansales.com

If you have any feedback on this post, please email me at mikec@arcadian sales.com

-Mike Crudele
ARCADIAN SALES
1-888-925-5967