2 GHz buffer with 2N390x

https://www.allaboutcircuits.com/technical-articles/voltage-buffer-simulation-composite-amplifier-simulation-boost-output-current-drive/



--

John Larkin Highland Technology, Inc

The cork popped merrily, and Lord Peter rose to his feet.
"Bunter", he said, "I give you a toast. The triumph of Instinct over Reason"

 

[Phil Hobbs]

On 2020-02-23 15:56, jlarkin@highlandsniptechnology.com wrote:

https://www.allaboutcircuits.com/technical-articles/voltage-buffer-simulation-composite-amplifier-simulation-boost-output-current-drive/



Gee, I wish I were smart enough to design that.

I once tried fairly hard to bandage up a MAT14 supermatch quad NPN to
make it work at higher bandwidth, by using gussied-up Darlington
connections with 40-GHz SiGe:C NPNs to return the AC base current to the
collector circuit.

It didn't work, because AFAICT there's no simple way to get rid of the
time constants formed by Rbb' and the interelectrode capacitances
without trashing the noise.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

 

On Sun, 23 Feb 2020 16:42:42 -0500, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

On 2020-02-23 15:56, jlarkin@highlandsniptechnology.com wrote:

https://www.allaboutcircuits.com/technical-articles/voltage-buffer-simulation-composite-amplifier-simulation-boost-output-current-drive/



Gee, I wish I were smart enough to design that.

I once tried fairly hard to bandage up a MAT14 supermatch quad NPN to
make it work at higher bandwidth, by using gussied-up Darlington
connections with 40-GHz SiGe:C NPNs to return the AC base current to the
collector circuit.

It didn't work, because AFAICT there's no simple way to get rid of the
time constants formed by Rbb' and the interelectrode capacitances
without trashing the noise.

Cheers

Phil Hobbs

Looking at his graphs, I figure that after the Ft's run out, the
signal is coupled through the various Cbe's. But that's not much in
the way of gain. Thermal runaway could be interesting too.

The electronic mags are pitiful these days.

Speaking of buffers, BUF602 is slick.



--

John Larkin Highland Technology, Inc

The cork popped merrily, and Lord Peter rose to his feet.
"Bunter", he said, "I give you a toast. The triumph of Instinct over Reason"

 

[Michael Terrell]

On Sunday, February 23, 2020 at 4:42:53 PM UTC-5, Phil Hobbs wrote:

On 2020-02-23 15:56, jlarkin wrote:

https://www.allaboutcircuits.com/technical-articles/voltage-buffer-simulation-composite-amplifier-simulation-boost-output-current-drive/



Gee, I wish I were smart enough to design that.

I once tried fairly hard to bandage up a MAT14 supermatch quad NPN to
make it work at higher bandwidth, by using gussied-up Darlington
connections with 40-GHz SiGe:C NPNs to return the AC base current to the
collector circuit.

It didn't work, because AFFLICT there's no simple way to get rid of the
time constants formed by Rbb' and the interelectrode capacitances
without trashing the noise.

That reminds of of a guy with a brand new two year degree who believe that he could get 5W of RF at 27 MHz form a 2N3055. I gave him one. As I expected, he didn't even get a miliwatt output, which was as low as I could measure in my home shop at 17. He was like Sloman. He knew everything, yet he often needed help to repair a TV.

 

[Bill Sloman]

On Monday, February 24, 2020 at 11:34:55 AM UTC+11, Michael Terrell wrote:

On Sunday, February 23, 2020 at 4:42:53 PM UTC-5, Phil Hobbs wrote:
On 2020-02-23 15:56, jlarkin wrote:

https://www.allaboutcircuits.com/technical-articles/voltage-buffer-simulation-composite-amplifier-simulation-boost-output-current-drive/



Gee, I wish I were smart enough to design that.

I once tried fairly hard to bandage up a MAT14 supermatch quad NPN to
make it work at higher bandwidth, by using gussied-up Darlington
connections with 40-GHz SiGe:C NPNs to return the AC base current to the
collector circuit.

It didn't work, because AFFLICT there's no simple way to get rid of the
time constants formed by Rbb' and the interelectrode capacitances
without trashing the noise.


That reminds of of a guy with a brand new two year degree who believe that he could get 5W of RF at 27 MHz from a 2N3055. I gave him one. As I expected, he didn't even get a miliwatt output, which was as low as I could measure in my home shop at 17. He was like Sloman.

Even I know that a 2N3055 is as slow as wet week.

> He knew everything, yet he often needed help to repair a TV.

And I certainly don't know everything, though I do know a lot more than Michael Terrell. The best definition of an expert is somebody who knows the limitations of their knowledge.

--
Bill Sloman, Sydney

 

On Sun, 23 Feb 2020 16:34:51 -0800 (PST), Michael Terrell
<terrell.michael.a@gmail.com> wrote:

On Sunday, February 23, 2020 at 4:42:53 PM UTC-5, Phil Hobbs wrote:
On 2020-02-23 15:56, jlarkin wrote:

https://www.allaboutcircuits.com/technical-articles/voltage-buffer-simulation-composite-amplifier-simulation-boost-output-current-drive/



Gee, I wish I were smart enough to design that.

I once tried fairly hard to bandage up a MAT14 supermatch quad NPN to
make it work at higher bandwidth, by using gussied-up Darlington
connections with 40-GHz SiGe:C NPNs to return the AC base current to the
collector circuit.

It didn't work, because AFFLICT there's no simple way to get rid of the
time constants formed by Rbb' and the interelectrode capacitances
without trashing the noise.


That reminds of of a guy with a brand new two year degree who believe that he could get 5W of RF at 27 MHz form a 2N3055. I gave him one. As I expected, he didn't even get a miliwatt output, which was as low as I could measure in my home shop at 17. He was like Sloman. He knew everything, yet he often needed help to repair a TV.

The guy is no lightweght. Maybe he was in a hurry or something.



--

John Larkin Highland Technology, Inc

The cork popped merrily, and Lord Peter rose to his feet.
"Bunter", he said, "I give you a toast. The triumph of Instinct over Reason"

 

[Tim Williams]

"Michael Terrell" <terrell.michael.a@gmail.com> wrote in message
news:1085d865-ec53-4158-aa2b-1446fff74951@googlegroups.com...

That reminds of of a guy with a brand new two year degree who believe
that he could get 5W of RF at 27 MHz form a 2N3055. I gave him one. As I
expected, he didn't even get a miliwatt output, which was as low as I
could measure in my home shop at 17. He was like Sloman. He knew
everything, yet he often needed help to repair a TV.

Entirely possible that he had done this, using a brand new epitaxial '3055.
Which shouldn't even exist, it should've been discontinued and put in a new
type number, say. While the one you had was made on the old process, and
barely useful for audio.

Although getting 5W even from an epitaxial version would probably require
more skill than he had, anyway. I'm not doubting that possibility.

Tim

--
Seven Transistor Labs, LLC
Electrical Engineering Consultation and Design
Website: https://www.seventransistorlabs.com/

 

[Michael Terrell]

On Sunday, February 23, 2020 at 8:26:09 PM UTC-5, highlandsniptechnology wrote:

On Sun, 23 Feb 2020 16:34:51 -0800 (PST), Michael Terrell wrote:

On Sunday, February 23, 2020 at 4:42:53 PM UTC-5, Phil Hobbs wrote:
On 2020-02-23 15:56, jlarkin wrote:

https://www.allaboutcircuits.com/technical-articles/voltage-buffer-simulation-composite-amplifier-simulation-boost-output-current-drive/



Gee, I wish I were smart enough to design that.

I once tried fairly hard to bandage up a MAT14 supermatch quad NPN to
make it work at higher bandwidth, by using gussied-up Darlington
connections with 40-GHz SiGe:C NPNs to return the AC base current to the
collector circuit.

It didn't work, because AFFLICT there's no simple way to get rid of the
time constants formed by Rbb' and the interelectrode capacitances
without trashing the noise.


That reminds of of a guy with a brand new two year degree who believe that he could get 5W of RF at 27 MHz form a 2N3055. I gave him one. As I expected, he didn't even get a miliwatt output, which was as low as I could measure in my home shop at 17. He was like Sloman. He knew everything, yet he often needed help to repair a TV.

The guy is no lightweght. Maybe he was in a hurry or something.

Which guy? There are too many guys in this thread.

 

On Sun, 23 Feb 2020 22:07:55 -0800 (PST), Michael Terrell
<terrell.michael.a@gmail.com> wrote:

On Sunday, February 23, 2020 at 8:26:09 PM UTC-5, highlandsniptechnology wrote:
On Sun, 23 Feb 2020 16:34:51 -0800 (PST), Michael Terrell wrote:

On Sunday, February 23, 2020 at 4:42:53 PM UTC-5, Phil Hobbs wrote:
On 2020-02-23 15:56, jlarkin wrote:

https://www.allaboutcircuits.com/technical-articles/voltage-buffer-simulation-composite-amplifier-simulation-boost-output-current-drive/



Gee, I wish I were smart enough to design that.

I once tried fairly hard to bandage up a MAT14 supermatch quad NPN to
make it work at higher bandwidth, by using gussied-up Darlington
connections with 40-GHz SiGe:C NPNs to return the AC base current to the
collector circuit.

It didn't work, because AFFLICT there's no simple way to get rid of the
time constants formed by Rbb' and the interelectrode capacitances
without trashing the noise.


That reminds of of a guy with a brand new two year degree who believe that he could get 5W of RF at 27 MHz form a 2N3055. I gave him one. As I expected, he didn't even get a miliwatt output, which was as low as I could measure in my home shop at 17. He was like Sloman. He knew everything, yet he often needed help to repair a TV.

The guy is no lightweght. Maybe he was in a hurry or something.

Which guy? There are too many guys in this thread.

Dr. Sergio Franco.




--

John Larkin Highland Technology, Inc

The cork popped merrily, and Lord Peter rose to his feet.
"Bunter", he said, "I give you a toast. The triumph of Instinct over Reason"

 

On Sun, 23 Feb 2020 21:39:15 -0600, "Tim Williams"
<tiwill@seventransistorlabs.com> wrote:

"Michael Terrell" <terrell.michael.a@gmail.com> wrote in message
news:1085d865-ec53-4158-aa2b-1446fff74951@googlegroups.com...
That reminds of of a guy with a brand new two year degree who believe
that he could get 5W of RF at 27 MHz form a 2N3055. I gave him one. As I
expected, he didn't even get a miliwatt output, which was as low as I
could measure in my home shop at 17. He was like Sloman. He knew
everything, yet he often needed help to repair a TV.

Getting that amount of power might have been possible in the past.

The specifications for 2N3055 are quite relaxed.

When some manufacturer tried to make some better transistors, but the
die was out of specs for the intended transistor, but well inside
2N3055 specs, the manufacturer put the die in a TO-3 can and labeled
it as "2N3055".

This was fine, but some manufacturer labeled even failed VHF power
transistors as "2N3055". When such transistor was put into a typical
DC/audio circuit, the transistor might oscillate like hell somewhere
in the VHF/UHF range

Entirely possible that he had done this, using a brand new epitaxial '3055.
Which shouldn't even exist, it should've been discontinued and put in a new
type number, say. While the one you had was made on the old process, and
barely useful for audio.

Although getting 5W even from an epitaxial version would probably require
more skill than he had, anyway. I'm not doubting that possibility.

Tim

 

[Michael Terrell]

On Sunday, February 23, 2020 at 10:39:15 PM UTC-5, Tim Williams wrote:

"Michael Terrell" wrote in message
news:1085d865-ec53-4158-aa2b-1446fff74951@googlegroups.com...
That reminds of of a guy with a brand new two year degree who believe
that he could get 5W of RF at 27 MHz form a 2N3055. I gave him one. As I
expected, he didn't even get a miliwatt output, which was as low as I
could measure in my home shop at 17. He was like Sloman. He knew
everything, yet he often needed help to repair a TV.


Entirely possible that he had done this, using a brand new epitaxial '3055.
Which shouldn't even exist, it should've been discontinued and put in a new
type number, say. While the one you had was made on the old process, and
barely useful for audio.

Although getting 5W even from an epitaxial version would probably require
more skill than he had, anyway. I'm not doubting that possibility.

Tim

It was in a Pace 2300, a popular CB radio made by Pathcom in the '60s and '70s. He was convinced that the custom RF output in a TO-3 was just an ordinary audio transistor. I showed him the RCA Databook that showed it had no chance of working. He claimed that RCA didn't know what they were doing. The Databook was from 1967, and I may still have it somewhere.

He had an attitude like Sloan. Anyone with a degree was infallible, and anyone else didn't deserve to live. I used to piss him off when I passed his bench at the shop. I would tell him what part was bad. He would curse me out, but more often than not he would yell, Do we have that part in stock. I took care of repairs of industrial electronics, and I knew our inventory better than anyone in the shop.

 

Michael Terrell <terrell.michael.a@gmail.com> wrote in
news:50569bec-b527-4165-a912-bc7f25c2c375@googlegroups.com:

On Sunday, February 23, 2020 at 8:26:09 PM UTC-5,
highlandsniptechnology wrote:
On Sun, 23 Feb 2020 16:34:51 -0800 (PST), Michael Terrell wrote:

On Sunday, February 23, 2020 at 4:42:53 PM UTC-5, Phil Hobbs
wrote:
On 2020-02-23 15:56, jlarkin wrote:

https://www.allaboutcircuits.com/technical-articles/voltage-b
uffer-s
imulation-composite-amplifier-simulation-boost-output-current-drive
/



Gee, I wish I were smart enough to design that.

I once tried fairly hard to bandage up a MAT14 supermatch quad
NPN to

make it work at higher bandwidth, by using gussied-up
Darlington connections with 40-GHz SiGe:C NPNs to return the
AC base current to t
he
collector circuit.

It didn't work, because AFFLICT there's no simple way to get
rid of th
e
time constants formed by Rbb' and the interelectrode
capacitances without trashing the noise.


That reminds of of a guy with a brand new two year degree who
believe
that he could get 5W of RF at 27 MHz form a 2N3055. I gave him
one. As I expected, he didn't even get a miliwatt output, which
was as low as I could measure in my home shop at 17. He was like
Sloman. He knew everything, yet he often needed help to repair a
TV.

The guy is no lightweght. Maybe he was in a hurry or something.

Which guy? There are too many guys in this thread.

You would like to come in here under that guise, but we have the
evidence! You are all tied up in the guy wires.

 

[Bill Sloman]

On Monday, February 24, 2020 at 5:05:29 PM UTC+11, Michael Terrell wrote:

On Sunday, February 23, 2020 at 10:39:15 PM UTC-5, Tim Williams wrote:
"Michael Terrell" wrote in message
news:1085d865-ec53-4158-aa2b-1446fff74951@googlegroups.com...
That reminds of of a guy with a brand new two year degree who believe
that he could get 5W of RF at 27 MHz form a 2N3055. I gave him one. As I
expected, he didn't even get a miliwatt output, which was as low as I
could measure in my home shop at 17. He was like Sloman. He knew
everything, yet he often needed help to repair a TV.


Entirely possible that he had done this, using a brand new epitaxial '3055.
Which shouldn't even exist, it should've been discontinued and put in a new
type number, say. While the one you had was made on the old process, and
barely useful for audio.

Although getting 5W even from an epitaxial version would probably require
more skill than he had, anyway. I'm not doubting that possibility.

Tim


It was in a Pace 2300, a popular CB radio made by Pathcom in the '60s and '70s. He was convinced that the custom RF output in a TO-3 was just an ordinary audio transistor. I showed him the RCA Databook that showed it had no chance of working. He claimed that RCA didn't know what they were doing.. The Databook was from 1967, and I may still have it somewhere.

He had an attitude like Sloman. Anyone with a degree was infallible, and anyone else didn't deserve to live.

Michael Terrell doesn't seem to noticed that I don't have any kind of degree in electronics - my Ph.D. is physical chemistry. I don't think that anybody would ever think that anybody with a degree would be infallible, and I've certainly worked with enough people with degrees to be well aware that it isn't remotely true.

> I used to piss him off when I passed his bench at the shop. I would tell him what part was bad. He would curse me out, but more often than not he would yell, Do we have that part in stock? I took care of repairs of industrial electronics, and I knew our inventory better than anyone in the shop.

A useful skill.

--
Bill Sloman, Sydney

 

On Mon, 24 Feb 2020 09:15:38 -0800 (PST), George Herold
<ggherold@gmail.com> wrote:

On Sunday, February 23, 2020 at 5:02:33 PM UTC-5, jla...@highlandsniptechnology.com wrote:
On Sun, 23 Feb 2020 16:42:42 -0500, Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:

On 2020-02-23 15:56, jlarkin@highlandsniptechnology.com wrote:

https://www.allaboutcircuits.com/technical-articles/voltage-buffer-simulation-composite-amplifier-simulation-boost-output-current-drive/



Gee, I wish I were smart enough to design that.

I once tried fairly hard to bandage up a MAT14 supermatch quad NPN to
make it work at higher bandwidth, by using gussied-up Darlington
connections with 40-GHz SiGe:C NPNs to return the AC base current to the
collector circuit.

It didn't work, because AFAICT there's no simple way to get rid of the
time constants formed by Rbb' and the interelectrode capacitances
without trashing the noise.

Cheers

Phil Hobbs

Looking at his graphs, I figure that after the Ft's run out, the
signal is coupled through the various Cbe's. But that's not much in
the way of gain. Thermal runaway could be interesting too.

Huh OK his gain graph droops at ~100MHz...
So what is the Ft (typical) of a 2n3904?

250 MHz sort of range. The PNP is a bit less than the NPN.



--

John Larkin Highland Technology, Inc

The cork popped merrily, and Lord Peter rose to his feet.
"Bunter", he said, "I give you a toast. The triumph of Instinct over Reason"

 

[George Herold]

On Sunday, February 23, 2020 at 5:02:33 PM UTC-5, jla...@highlandsniptechnology.com wrote:

On Sun, 23 Feb 2020 16:42:42 -0500, Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:

On 2020-02-23 15:56, jlarkin@highlandsniptechnology.com wrote:

https://www.allaboutcircuits.com/technical-articles/voltage-buffer-simulation-composite-amplifier-simulation-boost-output-current-drive/



Gee, I wish I were smart enough to design that.

I once tried fairly hard to bandage up a MAT14 supermatch quad NPN to
make it work at higher bandwidth, by using gussied-up Darlington
connections with 40-GHz SiGe:C NPNs to return the AC base current to the
collector circuit.

It didn't work, because AFAICT there's no simple way to get rid of the
time constants formed by Rbb' and the interelectrode capacitances
without trashing the noise.

Cheers

Phil Hobbs

Looking at his graphs, I figure that after the Ft's run out, the
signal is coupled through the various Cbe's. But that's not much in
the way of gain. Thermal runaway could be interesting too.

Huh OK his gain graph droops at ~100MHz...
So what is the Ft (typical) of a 2n3904?

George H.

The electronic mags are pitiful these days.

Speaking of buffers, BUF602 is slick.



--

John Larkin Highland Technology, Inc

The cork popped merrily, and Lord Peter rose to his feet.
"Bunter", he said, "I give you a toast. The triumph of Instinct over Reason"

 

[George Herold]

On Monday, February 24, 2020 at 1:23:38 AM UTC-5, jla...@highlandsniptechnology.com wrote:

On Sun, 23 Feb 2020 22:07:55 -0800 (PST), Michael Terrell
terrell.michael.a@gmail.com> wrote:

On Sunday, February 23, 2020 at 8:26:09 PM UTC-5, highlandsniptechnology wrote:
On Sun, 23 Feb 2020 16:34:51 -0800 (PST), Michael Terrell wrote:

On Sunday, February 23, 2020 at 4:42:53 PM UTC-5, Phil Hobbs wrote:
On 2020-02-23 15:56, jlarkin wrote:

https://www.allaboutcircuits.com/technical-articles/voltage-buffer-simulation-composite-amplifier-simulation-boost-output-current-drive/



Gee, I wish I were smart enough to design that.

I once tried fairly hard to bandage up a MAT14 supermatch quad NPN to
make it work at higher bandwidth, by using gussied-up Darlington
connections with 40-GHz SiGe:C NPNs to return the AC base current to the
collector circuit.

It didn't work, because AFFLICT there's no simple way to get rid of the
time constants formed by Rbb' and the interelectrode capacitances
without trashing the noise.


That reminds of of a guy with a brand new two year degree who believe that he could get 5W of RF at 27 MHz form a 2N3055. I gave him one. As I expected, he didn't even get a miliwatt output, which was as low as I could measure in my home shop at 17. He was like Sloman. He knew everything, yet he often needed help to repair a TV.

The guy is no lightweght. Maybe he was in a hurry or something.

Which guy? There are too many guys in this thread.

Dr. Sergio Franco.

Huh S. Franco wrote one of my favorite opamp books. I better go read the
article. (I thought it was hooey from the comments.)

George H.

--

John Larkin Highland Technology, Inc

The cork popped merrily, and Lord Peter rose to his feet.
"Bunter", he said, "I give you a toast. The triumph of Instinct over Reason"

 

[Mikko OH2HVJ]

George Herold <ggherold@gmail.com> writes:

Huh OK his gain graph droops at ~100MHz...
So what is the Ft (typical) of a 2n3904?

I've measured 30-300 MHz depending on mfg 1994-2015. Processes evolve and
generic partnumbers, too.

--
mikko

 

[Phil Hobbs]

On 2020-02-24 16:36, Mikko OH2HVJ wrote:

George Herold <ggherold@gmail.com> writes:

Huh OK his gain graph droops at ~100MHz...
So what is the Ft (typical) of a 2n3904?

I've measured 30-300 MHz depending on mfg 1994-2015. Processes evolve and
generic partnumbers, too.

30 MHz peak f_T for a 2N3904?

350-400 MHz at ~10-30 mA iirc.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

 

[George Herold]

On Monday, February 24, 2020 at 4:36:47 PM UTC-5, Mikko OH2HVJ wrote:

George Herold <ggherold@gmail.com> writes:

Huh OK his gain graph droops at ~100MHz...
So what is the Ft (typical) of a 2n3904?

I've measured 30-300 MHz depending on mfg 1994-2015. Processes evolve and
generic partnumbers, too.

--
mikko

Thanks!
GH

 

[Joerg]

On 2020-02-23 12:56, jlarkin@highlandsniptechnology.com wrote:

https://www.allaboutcircuits.com/technical-articles/voltage-buffer-simulation-composite-amplifier-simulation-boost-output-current-drive/

That reminds me of the moped tuning that the guys did in my high school
days. Going 50mph on a screaming 50ccm engine running way beyond
redline. Unfortunately one classmate died that way, the brakes couldn't
hold up.

--
Regards, Joerg

http://www.analogconsultants.com/