I have mapped to CMOS logic family. The probe impedance is 20K. I am seeing a voltage of 2.0 V on a static pin on which I was expecting 3.3V. -----Original Message----- From: olaney@xxxxxxxx [mailto:olaney@xxxxxxxx]=20 Sent: Monday, July 30, 2007 12:00 PM To: prajitsnair@xxxxxxxxx Cc: SRINIVASAN ANAND-B06739; si-list@xxxxxxxxxxxxx Subject: Re: [SI-LIST] Re: LA probes Does the logic analyzer allow you to specify the logic family parameters? You might have the wrong setting, for instance PECL loading on a CMOS signal. Orin On Mon, 30 Jul 2007 15:19:39 +0900 "PRAJIT S NAIR" <prajitsnair@xxxxxxxxx> writes: > Dear Anand > It may be happening because of probe loading. Please check your Probe=20 > Capacitance, Frequency of Operation and also Load impedance. >=20 >=20 > Best Regards > Prajit >=20 >=20 > On 7/30/07, SRINIVASAN ANAND-B06739 <anand.srinivasan@xxxxxxxxxxxxx> > wrote: > > > > Content-Type: text/plain; > > charset=3D"us-ascii" > > Content-Transfer-Encoding: quoted-printable Hi All, I have a=20 > > problem. Given below is a topology that i have.=3D20 > > > > > > > > =3D20 > > > > =3D20 > > > > I have a bidirectional bus which connects a FPGA to the CHIP. The=20 > > distance between them is 2 inches. Now to probe this bus, i have > the > > signals coming out to the right at a distance of about 6 inches.=20 > Note > > that i am using active probes to probe this interface and there > are NO > > buffers on the line between the chip and LA probes. Now the > problem is > > that when the LA is plugged in I find that the strength of the > signals > > driven by the chip comes down from 3.3V to 2V. Without the LA > plugged, > > the signal strength remains intact. Could anyone help me in=20 > > understanding this? If a solution is possible to get around this, > it > > will be great. > > > > =3D20 > > Regards, > > Anand > > > > =3D20 > > > > =3D20 > > > > > > > > > > -- Binary/unsupported file stripped by Ecartis -- > > -- Type: image/jpeg > > -- File: Outlook.jpg > > -- Desc: Outlook.jpg > > > > > > ------------------------------------------------------------------ > > To unsubscribe from si-list: > > si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject > field > > > > or to administer your membership from a web page, go to: > > //www.freelists.org/webpage/si-list > > > > For help: > > si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field > > > > > > List technical documents are available at: > > http://www.si-list.net > > > > List archives are viewable at: > > //www.freelists.org/archives/si-list > > or at our remote archives: > > http://groups.yahoo.com/group/si-list/messages > > Old (prior to June 6, 2001) list archives are viewable at: > > http://www.qsl.net/wb6tpu > > > > > > >=20 >=20 > ------------------------------------------------------------------ > To unsubscribe from si-list: > si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field >=20 > or to administer your membership from a web page, go to: > //www.freelists.org/webpage/si-list >=20 > For help: > si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field >=20 >=20 > List technical documents are available at: > http://www.si-list.net >=20 > List archives are viewable at: =20 > //www.freelists.org/archives/si-list > or at our remote archives: > http://groups.yahoo.com/group/si-list/messages > Old (prior to June 6, 2001) list archives are viewable at: > http://www.qsl.net/wb6tpu > =20 >=20 >=20 >=20 ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List technical documents are available at: http://www.si-list.net List archives are viewable at: //www.freelists.org/archives/si-list or at our remote archives: http://groups.yahoo.com/group/si-list/messages Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu