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OT: Howland Current Source/Pump

Jung's book says see Howland reference at end of this chapter, then there is none, except for a Motorola ApNote analysing OpAmp current mirrors :-(

Graeme doesn't mention them.

...Jim Thompson

--
|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
|  Analog/Mixed-Signal ASIC\'s and Discrete Systems  |    manus    |
|  Phoenix, Arizona            Voice:(480)460-2350  |             |
|  E-mail Address at Website     Fax:(480)460-2142  |  Brass Rat  |
|       http://www.analog-innovations.com           |    1962     |
             
     It\'s what you learn, after you know it all, that counts.
Reply to
Jim Thompson
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You are correct, IIRC, the paper is dated 1955.

--
 Thanks,
    - Win
Reply to
Winfield Hill

Snip....

You may not have seen Fred Blogg's comment that:

"It is most likely that the VCCS disclosure is buried in a biophysics paper as an example circuit realizing a higher accomplishment or report, and you may not find a paper of the type "Novel OA Current Source..." etc."

I think he's right on this.

Reply to
The Phantom

In another IEEE paper found with IEEEXplore, the authors say that variants of the original circuit have been proposed (I'm sure they have!), and give as a reference a book, "Operational Amplifiers: Theory and Practice", by J. K. Roberge. Perhaps Roberge has a reference. I think I have that book somewhere, but I can't lay my hands on it right now. Maybe someone else has it, or maybe you do, Jim.

Reply to
The Phantom

I suspect so. I've sent an E-mail to Bob Pease to see if he can shed any light.

...Jim Thompson

--
|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
|  Analog/Mixed-Signal ASIC\'s and Discrete Systems  |    manus    |
|  Phoenix, Arizona            Voice:(480)460-2350  |             |
|  E-mail Address at Website     Fax:(480)460-2142  |  Brass Rat  |
|       http://www.analog-innovations.com           |    1962     |
             
     It\'s what you learn, after you know it all, that counts.
Reply to
Jim Thompson

I don't have that one, but Steve G. does, "at home" ;-)

...Jim Thompson

--
|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
|  Analog/Mixed-Signal ASIC\'s and Discrete Systems  |    manus    |
|  Phoenix, Arizona            Voice:(480)460-2350  |             |
|  E-mail Address at Website     Fax:(480)460-2142  |  Brass Rat  |
|       http://www.analog-innovations.com           |    1962     |
             
     It\'s what you learn, after you know it all, that counts.
Reply to
Jim Thompson

I have it- my favorite text.

Reply to
Fred Bloggs

That book has absolutely no references or bibliography at all. Howland current source is on page 454.

Reply to
Fred Bloggs

Interestingly, a coworker and coauthor is still alive and invites email queries:

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Reply to
Fred Bloggs

Hey, Fred, you wouldn't be having more than your share of fun right now, would you? :-) I have a suggestion. Why not change back to your real name? It could be seriously gratifying.

--
 Thanks,
    - Win
Reply to
Winfield Hill

Bob Pease's reply to my inquiry...

" *** I have NO idea where Brad Howland ever wrote the original paper on his Current Pump . He mightta just sent a letter to George Philbrick. I never saw it. Of course, the original one had

4 R's; and the "Improved one" had 5 R's. I don't know if that was really invented by Mr. Howland.... What else can I tell you? /rap

This was not published in the 1961 era Philbrick App Notes, but it was put in the 1965 Apps Manual. "

=====

Now take a look at my patent 3,644,835... contains a "Howland" source except no "set" R's, it's current driven.

The patent also contains the phase detector concept that Hans would like to claim he "introduced".

(;-)

...Jim Thompson

--
|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
|  Analog/Mixed-Signal ASIC\'s and Discrete Systems  |    manus    |
|  Phoenix, Arizona            Voice:(480)460-2350  |             |
|  E-mail Address at Website     Fax:(480)460-2142  |  Brass Rat  |
|       http://www.analog-innovations.com           |    1962     |
             
     It\'s what you learn, after you know it all, that counts.
Reply to
Jim Thompson

Looks like a cheap knockoff of synchronous rectification to me...

Reply to
Fred Bloggs

What do you think a Gilbert cell is?

...Jim Thompson

--
|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
|  Analog/Mixed-Signal ASIC\'s and Discrete Systems  |    manus    |
|  Phoenix, Arizona            Voice:(480)460-2350  |             |
|  E-mail Address at Website     Fax:(480)460-2142  |  Brass Rat  |
|       http://www.analog-innovations.com           |    1962     |
             
     It\'s what you learn, after you know it all, that counts.
Reply to
Jim Thompson

Actually my phase detector (a PECL XOR, aka "synchronous rectification") pre-dates the Gilbert cell, which added linearization to make it an ANALOG multiplier.

...Jim Thompson

--
|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
|  Analog/Mixed-Signal ASIC\'s and Discrete Systems  |    manus    |
|  Phoenix, Arizona            Voice:(480)460-2350  |             |
|  E-mail Address at Website     Fax:(480)460-2142  |  Brass Rat  |
|       http://www.analog-innovations.com           |    1962     |
             
     It\'s what you learn, after you know it all, that counts.
Reply to
Jim Thompson

Hello Jim,

Then I wonder how this current source got its name. From the 1965 apps manual?

Regards, Joerg

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Reply to
Joerg

Just call it the "Thompson current source" and I'll be happy ;-)

...Jim Thompson

--
|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
|  Analog/Mixed-Signal ASIC\'s and Discrete Systems  |    manus    |
|  Phoenix, Arizona            Voice:(480)460-2350  |             |
|  E-mail Address at Website     Fax:(480)460-2142  |  Brass Rat  |
|       http://www.analog-innovations.com           |    1962     |
             
     It\'s what you learn, after you know it all, that counts.
Reply to
Jim Thompson

Hello Jim,

Nah, can't do that. There is already the Thompson Gun:

formatting link

Regards, Joerg

formatting link

Reply to
Joerg

I've fired one of those when I was a kid... seated on the ground, elbows on knees as tripod. Whirled me around so fast I almost shot my uncle who was madly running in a circle ;-)

...Jim Thompson

--
|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
|  Analog/Mixed-Signal ASIC\'s and Discrete Systems  |    manus    |
|  Phoenix, Arizona            Voice:(480)460-2350  |             |
|  E-mail Address at Website     Fax:(480)460-2142  |  Brass Rat  |
|       http://www.analog-innovations.com           |    1962     |
             
     It\'s what you learn, after you know it all, that counts.
Reply to
Jim Thompson

That was the name my professor at Berlin TU(1971) was calling it. Must be referring to you or some other Thompson?

--
ciao Ban
Apricale, Italy
Reply to
Ban

Could be me. I know that a professor at Rensselaer Polytechnic Institute (RPI) was using several of my early chip designs as teaching examples.

Also Tom Frederiksen credits me for current mirror concepts in his book, "Intuitive IC Op Amps".

Was your professor referring to the positive and negative feedback OpAmp configuration? The only place I remember using that configuration was in the analog phase detector (originally in a TACAN receiver).

...Jim Thompson

--
|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
|  Analog/Mixed-Signal ASIC\'s and Discrete Systems  |    manus    |
|  Phoenix, Arizona            Voice:(480)460-2350  |             |
|  E-mail Address at Website     Fax:(480)460-2142  |  Brass Rat  |
|       http://www.analog-innovations.com           |    1962     |
             
     It\'s what you learn, after you know it all, that counts.
Reply to
Jim Thompson

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