It's hard to say what exactly you are doing and what model you have but can try to increase the value of the pull-up resistor. You current may be too high and the transistor may not act as a switch as you would expect.
Mira --- Bevan Weiss <[EMAIL PROTECTED]> wrote: > > >-----Original Message----- > >From: [EMAIL PROTECTED] > >[mailto:[EMAIL PROTECTED] On Behalf Of > tastingfan > >tastingfan > >Sent: Thursday, August 11, 2005 4:10 PM > >To: [email protected] > >Subject: [PEDA] simulation of an Open Drain > > > > > >Hi, > > > > > > > >I want to simulate an Open Drain circuit (N > channel). The > >parameters are following > > > > > > > >1, Gate: input (impulses): 0-3.3V > > > >2, Drain connected with a pull-up of 4.7K to 5V > > > >3, Source connected with GND. > > > > > > > >But the output range is 4.891-5V, not 0V-5V. Why? > > > > > > > >Best Regards > > > >Tasting_fan > > The voltage swing will depend on what the channel > resistance of the FET is. > Make sure that the 3.3V pulse is above the threshold > voltage of the device, > and that the pulse width is larger than 5 RC time > constants (the gate has > capacitance + resistance and the source will have > resistance). > Make sure the substrate is connected to GND also. > > This seems very similar to another question that > you've asked in this forum > before. > > > Regards, > Bevan > > > ____________________________________________________________ > You are subscribed to the PEDA discussion forum > > To Post messages: > mailto:[email protected] > > Unsubscribe and Other Options: > http://techservinc.com/mailman/listinfo/peda_techservinc.com > > Browse or Search Old Archives (2001-2004): > http://www.mail-archive.com/[email protected] > > Browse or Search Current Archives (2004-Current): > http://www.mail-archive.com/[email protected] > > ____________________________________________________ Start your day with Yahoo! - make it your home page http://www.yahoo.com/r/hs ____________________________________________________________ You are subscribed to the PEDA discussion forum To Post messages: mailto:[email protected] Unsubscribe and Other Options: http://techservinc.com/mailman/listinfo/peda_techservinc.com Browse or Search Old Archives (2001-2004): http://www.mail-archive.com/[email protected] Browse or Search Current Archives (2004-Current): http://www.mail-archive.com/[email protected]
