Sogo, Oscillators - use IOLEVEL=3D2 for slow ramp inputs to prevent getting stuck in 'X' state One of the problems in using a digital gate in an oscillator, is that the default digital I/O level is set to 1, which means that the allowed states are 0, R(rising), 1, F (falling), Z (high impedance) and X (indeterminate). Since an oscillator is trying to use a digital part in the linear domain, it usually gets to R, F, or X and stays there as a steady state, and never oscillates. To fix this, go to the gate(s) you are using, and change their IOLEVEL from 0(the default) to 2. This goes to a simplified state machine that basically has 0 and 1. This should allow the oscillation to begin. Regards, Chris Schmolze -----Original Message----- From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] On Behalf Of Sogo Hsu Sent: Wednesday, June 09, 2004 1:51 AM To: si-list@xxxxxxxxxxxxx Subject: [SI-LIST] Crystal oscillator simulation in time domain by Pspice Hi, Gurus, I tried to simulate a typical oscillator and investigate the start-up=20 time by Pspice. The oscillator consists of an inverter and crystal.=20 the crystal was modeled by it's equivalent circuit. However, we were=20 unable to start up the oscillation successfully. It seems that is the=20 limitation of Newton-Raphson algorithm. The algorithm ensures the=20 circuit simulation can converge to solution. Accordingly, it gives up=20 the oscillation solution to avoid 'diverge' issue. How can I solve=20 this issue and bypass the converge requirement to achieve=20 oscillation? Thank you for your comments in advance. Sogo Hsu Ph. D. Foxconn ------------------------------------------------------------------ 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 FAQ wiki page is located at: http://si-list.org/wiki/wiki.pl?Si-List_FAQ List technical documents are available at: http://www.si-list.org 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 ------------------------------------------------------------------ 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 FAQ wiki page is located at: http://si-list.org/wiki/wiki.pl?Si-List_FAQ List technical documents are available at: http://www.si-list.org 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