October 6th, 2008 Weird chip
Today, while i was desoldering some parts from a laptop motherboard i came across a strange chip, at least strange for me because i never saw anything like this before. The chip is labeled LF-H80P, i did a quick search on google but nothing interesting showed up.
At first glance, the chip looks perfectly normal, but when you look on it’s back you can see four inductance windings:
October 6th, 2008 at 4:29 pm
This looks like a ethernet transformer. They’re used between RJ45 plug and the ethernet MAC controller. This stuff is ~ common, but this ref isn’t.
Bye
October 6th, 2008 at 4:54 pm
That’s weird…
My guess is that they just stuffed some inductors into a plastic case to make it easier for the machines assembling the circuit board to place/solder.
October 6th, 2008 at 7:55 pm
Its the magnetics for an ethernet port - theirs always a 1:1 transformer between the tranceiver and the cable to give the ‘puter some degree of protection should a wiring fault occur
October 6th, 2008 at 9:59 pm
thanks guys for clearing things out. This chip was taken from a laptop motherboard, but i also desoldered parts from two desktop computer motherboards and i haven’t found anything like this on them.
October 7th, 2008 at 8:11 am
Most mobos these days have the magnetics integrated in to the connector to reduce the amount of board space required. Tbh, im suprised to see magnetics seperate on a laptop where space is critical
October 7th, 2008 at 9:10 am
unfortunately i haven’t took the connectors out of the desktop computer motherboards so i can’t take a look
, but thanks
October 29th, 2008 at 8:30 pm
@Dan: The usual RJ-45 connector (with transformer) could be too big for the laptop (too high or too long), so they probably put a conector and the “magnetics” seperately.
October 29th, 2008 at 9:09 pm
Božo that sounds like a nice and plausible explanation. Probably that was the reason they did it that way.