Fast And Gate, 1 Ghz
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From: osr on 16 Feb 2010 17:08 Since this is for my friend's field diagnostics, the pretrigger is the box held in his right hand while he hits the doctor's trigger pedal with his right foot. I've been told to look at LVDS receivers for the compare portion, any suggestions for a fast switch for the current steering, if we go that way? I'm looking at some 2N918 in the scrap box, but with a 2 nsec rise and fall that is probably too slow... Steve
From: Joerg on 16 Feb 2010 17:40 osr(a)uakron.edu wrote: > Since this is for my friend's field diagnostics, the pretrigger is the > box held in his right hand while he hits the doctor's trigger pedal > with his right foot. > > I've been told to look at LVDS receivers for the compare portion, any > suggestions for a fast switch for the current steering, if we go that > way? I'm looking at some 2N918 in the scrap box, but with a 2 nsec > rise and fall that is probably too slow... > That would be like showing up at the Daytona race track in an AMC Gremlin :-) You'd probably be looking at low capacitance RF transistors like the BFP620: http://www.infineon.com/dgdl/bfp620.pdf?folderId=db3a30431400ef68011425b291f205c5&fileId=db3a30431400ef680114274deb27072a Although, depending on your precision requirements even the old BFS17 might suffice. It can do a little under a nanosecond. When using really hot RF transistors be careful, they can be oscillating without you even knowing they do. -- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.
From: langwadt on 16 Feb 2010 17:45 On 16 Feb., 23:08, o...(a)uakron.edu wrote: > Since this is for my friend's field diagnostics, the pretrigger is the > box held in his right hand while he hits the doctor's trigger pedal > with his right foot. > > I've been told to look at LVDS receivers for the compare portion, any > suggestions for a fast switch for the current steering, if we go that > way? I'm looking at some 2N918 in the scrap box, but with a 2 nsec > rise and fall that is probably too slow... > > Steve I wonder if you could hack it all with something like this? http://www.onsemi.com/pub_link/Collateral/NB4N316M-D.PDF -Lasse
From: Jim Thompson on 16 Feb 2010 18:01 On Tue, 16 Feb 2010 14:40:00 -0800, Joerg <invalid(a)invalid.invalid> wrote: >osr(a)uakron.edu wrote: >> Since this is for my friend's field diagnostics, the pretrigger is the >> box held in his right hand while he hits the doctor's trigger pedal >> with his right foot. >> >> I've been told to look at LVDS receivers for the compare portion, any >> suggestions for a fast switch for the current steering, if we go that >> way? I'm looking at some 2N918 in the scrap box, but with a 2 nsec >> rise and fall that is probably too slow... >> > >That would be like showing up at the Daytona race track in an AMC >Gremlin :-) > >You'd probably be looking at low capacitance RF transistors like the BFP620: >http://www.infineon.com/dgdl/bfp620.pdf?folderId=db3a30431400ef68011425b291f205c5&fileId=db3a30431400ef680114274deb27072a > >Although, depending on your precision requirements even the old BFS17 >might suffice. It can do a little under a nanosecond. When using really >hot RF transistors be careful, they can be oscillating without you even >knowing they do. A PECL NOR is an AND for low-true... that's quite fast. ...Jim Thompson -- | James E.Thompson, CTO | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | I love to cook with wine. Sometimes I even put it in the food.
From: Joerg on 16 Feb 2010 18:06
Jim Thompson wrote: > On Tue, 16 Feb 2010 14:40:00 -0800, Joerg <invalid(a)invalid.invalid> > wrote: > >> osr(a)uakron.edu wrote: >>> Since this is for my friend's field diagnostics, the pretrigger is the >>> box held in his right hand while he hits the doctor's trigger pedal >>> with his right foot. >>> >>> I've been told to look at LVDS receivers for the compare portion, any >>> suggestions for a fast switch for the current steering, if we go that >>> way? I'm looking at some 2N918 in the scrap box, but with a 2 nsec >>> rise and fall that is probably too slow... >>> >> That would be like showing up at the Daytona race track in an AMC >> Gremlin :-) >> >> You'd probably be looking at low capacitance RF transistors like the BFP620: >> http://www.infineon.com/dgdl/bfp620.pdf?folderId=db3a30431400ef68011425b291f205c5&fileId=db3a30431400ef680114274deb27072a >> >> Although, depending on your precision requirements even the old BFS17 >> might suffice. It can do a little under a nanosecond. When using really >> hot RF transistors be careful, they can be oscillating without you even >> knowing they do. > > A PECL NOR is an AND for low-true... that's quite fast. > Yeah, but you can't get them for a buck :-) If the laser pulse comes in with gusto I'd be tempted to just amplify it as needed (maybe with a limiter) and run it point blank into the base of the RF transistor. -- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM. |