Favorite jellybean ~HF BJT?

Question

2N2369 is an old standby... kind of high current (200mA), like a '3904 sped up about 2-3 times. Not well specified though, I suppose because it's so old. I'm thinking in the 20V, 50mA range, fT maybe 0.5-1GHz. Like if you wanted to make old school RTL circuits that run as fast as 74S TTL. MPSH11 looks good, and '81 looks like its complement. I've used PN3563 before (complement PN4258? unobtainium?).

Any favorites?

I'm not looking for SMTs or anything over 3GHz. I'm still exploring the through-hole era, where it helps if the transistor doesn't oscillate on its own legs. :)

Tim

Jim Thompson · Accepted Answer

2N2369 is a GOLD-DOPED device designed primarily for low-storage-timeswitching		                                        ...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  |    1962     |                                 Help save the environment!              Please dispose of socialism properly!

Jan Panteltje · Answer

On a sunny day (Thu, 17 Dec 2009 12:33:30 -0600) it happened "Tim Williams" wrote in :

BFR91, 20V Vcb, but only 12 V Vce, 50 mA, 2GHz.. low Ccb .5 pF, Cce .3 pF can be used trough hole and surface mount, seems stable here....

Tim Williams · Answer

"Jim Thompson"  Yup.Is that all you had to say, your sentence seems to end suddenly?What's your favorite, Jim?  And don't say InP monolithic, because that doesn't count.  ;-)Tim-- Deep Friar: a very philosophical monk.Website:

Tim Williams · Answer

Ewww, TO-50. Hmm, Vishay claims 5GHz, planar ground a must. And like most RF parts, it lacks DC parameters...

Yeah, stable at what frequency and bandwidth? 800MHz, or wideband? ;-)

Tim

Jim Thompson · Answer

I was going to opine that it probably wasn't all that good for RF, butdecided I wasn't sure about that ;-)XFAB XB06 BiCMOS process QNBROA (NPN ;-)		                                        ...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  |    1962     |                                 Help save the environment!              Please dispose of socialism properly!

Joerg · Answer

Well, not much to write home about but slim pickens if you don't want SOT23:Characteristics similar to:-- Regards, Joerg"gmail" domain blocked because of excessive spam.Use another domain or send PM.

Jan Panteltje · Answer

On a sunny day (Thu, 17 Dec 2009 14:58:51 -0600) it happened "Tim Williams" wrote in :

I am using it as variable cap to tune a xtal osc in a camera. no special decoupling ftp://panteltje.com/pub/PAL_camera_freq_control_img_1600.jpg

If your layout is sane, why should it oscillate?

Jan Panteltje · Answer

On a sunny day (Thu, 17 Dec 2009 14:58:51 -0600) it happened "Tim Williams" wrote in :

BTW, here are the (LT) spice models for BFR91 and BFR96:

.MODEL BFR91 NPN ( BF=101 VAF=96 VAR=9.6 RC=9 RB=5

+RE=.149 IKF=0.25E-01 ISE=0.32E-14 TF=0.178E-10 +TR=0.13E-08 ITF=0.40E-01 VTF=0.40E+01 CJC=1.271E-12 +CJE=2.361E-12 XTI=3.0 NE=1.5 ISC=0.11E-14 EG=1.11 +XTB=1.5 BR=2.63 VJC=0.75 VJE=0.75 IS=0.35E-15 +MJC=0.33 MJE=0.33 XTF=4.0 IKR=0.25E-01 KF=0.1E-14 +NC=1.7 FC=0.50 RBM=3.5 IRB=0.35E-02 XCJC=0.5 )

.MODEL BFR96 NPN ( BF=99 VAF=120 VAR=12.0 RC=6.1 RB=2.7

+RE=.029 IKF=0.70E-01 ISE=0.90E-14 TF=0.178E-10 +TR=0.13E-08 ITF=0.67E-01 VTF=0.50E+01 CJC=1.854E-12 +CJE=1.709E-12 XTI=3.0 NE=1.5 ISC=0.30E-14 EG=1.11 +XTB=1.5 BR=2.57 VJC=0.75 VJE=0.75 IS=0.10E-14 +MJC=0.33 MJE=0.33 XTF=4.0 IKR=0.70E-01 KF=0.1E-14 +NC=1.7 FC=0.50 RBM=1.9 IRB=0.10E-01 XCJC=0.5 )

I have appended these to standard.bjt

John Larkin · Answer

I like BFS17. It plenty fast but not so fast that it oscillates all on its own, like many parts do. It is surface mount, which keeps the parasitics down.

BFT25, Phil Hobbs' favorite transistor, is remarkable too.

John

Joerg · Answer

I always keep a (large) vial of those in stock here, just like we do with Sierra Nevada Pale Ale. Not sure why Tim absolutely wants thru-hole, SOT23 is easy to solder onto experimental board. Problem with thru-hole is that anything fast almost needs to be soldered down with its can like they did on old UHF tuner. And the market for that stuff is gone.

That one is pretty low noise but at 20 cents incredibly expensive :-)

Bill Sloman · Answer

s"7I used a few BFR96 back in 1989-91, but we mostly used the BFR92 (NPN)and the BFT92 (PNP) where we needed some speed, always with around 33R(or thereabouts) of base-stopper, right up against the base.Cheap, easy to buy (Farnell) and tolerably quick.Won't take muchreverse bias across the base.--Bill Sloman, Nijmegen

Favorite jellybean ~HF BJT?

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