"Low Noise Electronic Design," Motchenbacher and Fitchen, 1973

A resource for technical documentation. Datasheets, application notes, instruction manuals, books and links to resources are found in the Document Library.
Post Reply
User avatar
mediatechnology
Posts: 3659
Joined: Sat Aug 11, 2007 2:34 pm
Location: Oak Cliff, Texas
Contact:

"Low Noise Electronic Design," Motchenbacher and Fitchen, 1973

Post by mediatechnology » Wed May 08, 2019 5:35 pm

"Low Noise Electronic Design," "Design with Feedback," Section 7-4, C.D. Motchenbacher, F.C. Fitchen, 1973.

The "op amp around the transistor" "current feedback" circuit shown by Demrow in 1968 https://proaudiodesignforum.com/forum/p ... =12&t=1052 and documented by Motchenbacher and Fitchen in 1973.
This is the single-ended half-circuit of the popular "Cohen" differential style preamp.


Image
"Low Noise Electronic Design," "Design with Feedback," Section 7-4, C.D. Motchenbacher, F.C. Fitchen, 1973. Figure 7-3.

Note the common base connection (figure 7-3a) with "current feedback."

"Low Noise Electronic Design," "Design with Feedback," Section 7-4, C.D. Motchenbacher, F.C. Fitchen, 1973. https://proaudiodesignforum.com/images/ ... on_7-4.pdf
https://ka-electronics.com

SOCIAL MEDIA PLATFORMS should advance FREEDOM OF SPEECH. Yet too many Americans have seen their accounts suspended, banned, or fraudulently reported for unclear “violations” of user policies. No matter your views, if you suspect political bias caused such an action to be taken against you, share your story with President Trump.
White House Tech Censorship Reporting Link: https://whitehouse.typeform.com/to/Jti9QH
The Most Banned Network In The World: https://www.infowars.com/show
BANNED VIDEO - UK Police Escort A Muslim Mob To ATTACK Tommy Robinson:https://www.newswars.com/censored-video ... n-england/

User avatar
JR.
Posts: 2684
Joined: Sat May 24, 2008 7:21 pm

Re: "Low Noise Electronic Design," Motchenbacher and Fitchen, 1973

Post by JR. » Thu May 09, 2019 11:02 am

Page 124... 8-)

I've shared this story before... back in the late 70s I was living about one town away from Bridgeport where Fitchen was teaching at University of Bridgeport. His phone number was in the phone book so I called him. I wanted to pick his brain about a Leach low noise topology that was unusual (he didn't know either). After a nice chat he asked me to contribute to a chapter for his next book... I demurred, I was not an academic (college dropout), but I gather Motchenbacher was also a working design engineer, and Fitchen was the professorial half of the team.

JR

User avatar
mediatechnology
Posts: 3659
Joined: Sat Aug 11, 2007 2:34 pm
Location: Oak Cliff, Texas
Contact:

Re: "Low Noise Electronic Design," Motchenbacher and Fitchen, 1973

Post by mediatechnology » Thu May 09, 2019 12:35 pm

Thanks John for that story.
Yes, page 124.

I had posted that page here elsewhere but I thought it deserved its own thread and index.
Its one of the more practical books and I enjoyed leafing through it again.

You don't see the common base circuit often unless its a mic preamp re-purposed as a bus summing amp or "current input" moving coil phono preamp.
https://ka-electronics.com

SOCIAL MEDIA PLATFORMS should advance FREEDOM OF SPEECH. Yet too many Americans have seen their accounts suspended, banned, or fraudulently reported for unclear “violations” of user policies. No matter your views, if you suspect political bias caused such an action to be taken against you, share your story with President Trump.
White House Tech Censorship Reporting Link: https://whitehouse.typeform.com/to/Jti9QH
The Most Banned Network In The World: https://www.infowars.com/show
BANNED VIDEO - UK Police Escort A Muslim Mob To ATTACK Tommy Robinson:https://www.newswars.com/censored-video ... n-england/

User avatar
JR.
Posts: 2684
Joined: Sat May 24, 2008 7:21 pm

Re: "Low Noise Electronic Design," Motchenbacher and Fitchen, 1973

Post by JR. » Sat May 11, 2019 3:04 pm

Yup we live in the time of "Bridging" input terminations that favor high Z.

MC is low Z source but even I tried to present a 10x termination impedance... but that was a very long time ago.

JR

Post Reply