Electronics > Beginners
Question on NPN Logic Inverter From Textbook
floobydust:
You'll never force an E-B junction to 5V without the transistor exploding. That graph should end at 1V.
Be careful, EE textbooks are written by academics and there are many errors. Always look for the latest edition or the errata. In university, the textbook errors and mistakes never ended despite the author having great credentials.
eev_carl:
Yeah, nothing in errata for 3rd, 4th, 5th editions (mine is 3rd)
floobydust:
I think the book mistake is to use the datasheet maximum spec of BVEBO, instead of VBE(on). Example:
2SC5200 power transistor: BVEBO 5V; VBE(on) 1.5V
2N3904/2N2222: BVEBO 6V; no spec for, but saturation graph is VBE(on) 1.0V
fourfathom:
--- Quote from: Wimberleytech on September 30, 2019, 05:25:31 pm ---I don't want to start a flame war, but I downloaded the book and within just a few minutes I found more incompleteness (arguably just wrong)--see if you can tell me what is wrong with Fig. 2.17. My point remains, no book can be complete, and the instance noted in this thread could have been more complete.
--- End quote ---
OK, you're right. I'm not a process/fab guy so I would have to study that figure long and hard, and still probably wouldn't spot the problem.
I did look at the graph showing +5V VBE, and that is obviously wrong. Skimming through the book I also noticed Fig 6.3, showing a single-NPN inverter with a direct connection to the base, and showing a transfer function input ranging from 0V to V+. So this is not an isolated problem in the book.
Wimberleytech:
--- Quote from: fourfathom on September 30, 2019, 09:52:09 pm ---
--- Quote from: Wimberleytech on September 30, 2019, 05:25:31 pm ---I don't want to start a flame war, but I downloaded the book and within just a few minutes I found more incompleteness (arguably just wrong)--see if you can tell me what is wrong with Fig. 2.17. My point remains, no book can be complete, and the instance noted in this thread could have been more complete.
--- End quote ---
OK, you're right. I'm not a process/fab guy so I would have to study that figure long and hard, and still probably wouldn't spot the problem.
I did look at the graph showing +5V VBE, and that is obviously wrong. Skimming through the book I also noticed Fig 6.3, showing a single-NPN inverter with a direct connection to the base, and showing a transfer function input ranging from 0V to V+. So this is not an isolated problem in the book.
--- End quote ---
Yeah, I skimmed the book...all 1300+ pages. I take issue with lots of things. Why teach H-biasing of MOSFETS? It is, frankly, useless information. I don't have a problem with typos and an equation faux pas here and there (I am an author and understand how easy it is to miss such things), but pedagogical issues are more problematic.
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version