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Consider this closed. I found that PECL receivers that can=20
operate at 3.3V (Moto MC100LVEL17) are defined with a=20
vCMR and vID that LVDS meets easily.
----- Original Message -----=20
From: John Lipsius=20
To: si-list posting=20
Sent: Saturday, July 10, 1999 7:22 PM
Subject: [SI-LIST] : LVDS to Differential LVPECL conversion?
Hello All,
=20
Presently, I've not found yet any IC that performs=20
LVDS to LVPECL conversion. Just need one pair=20
converted.=20
=20
My current strategy is to use the following passive method:
(50 ohm system; the following applies to each=20
line in the LVDS diff. pair)
short segment with :
10pF in series then a VBB bias of 680ohm pullup to 3.3v=20
and 1Kohm pulldown to VEE(gnd).
schematically:
LVDS input----cap---bias---LVPECL diff. driver for fanout on pcb=20
Q1: Seem ok (provided all the other SI rules followed)?=20
=20
Q2: Is use of a ferrite bead between pullup and/or pulldown=20
resistor and its plane, to filter out noise at the VBB=20
bias point, a good idea or just overkill?
Thanks,
John Lipsius
MTS
Cyras Systems, Inc.
510-623-6631
=20
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------=_NextPart_000_09B1_01BECBC0.B7C2F840-- **** To unsubscribe from si-list: send e-mail to [email protected]. In the BODY of message put: UNSUBSCRIBE si-list, for more help, put HELP. si-list archives are accessible at http://www.qsl.net/wb6tpu/si-list ****----- Original Message -----From:=20 John = Lipsius=20To: si-list postingSent: Saturday, July 10, 1999 = 7:22=20 PMSubject: [SI-LIST] : LVDS to = Differential=20 LVPECL conversion?Hello All,Presently, I've not found yet any IC = that=20 performsLVDS to LVPECL conversion. Just = need one=20 pairconverted.My current strategy is to use the following passive method:(50 ohm system; the following applies = to each=20line in the LVDS diff. = pair)short segment with :10pF in series then a VBB bias of = 680ohm pullup to 3.3vand 1Kohm pulldown to VEE(gnd).schematically:LVDS input----cap---bias---LVPECL = diff. driver=20 for fanout on pcbQ1: Seem ok (provided all = the other=20 SI rules followed)?Q2: Is use of a ferrite bead = between pullup=20 and/or pulldown= resistor and=20 its plane, to filter out noise at = the VBB=20= bias=20 point, a good idea or = just=20 overkill?Thanks,John Lipsius
= MTS
Cyras=20 Systems, Inc.
510-623-6631