be
Please to remember all of the s, h, y, z, etc parameters are usually small signal linearizations. They fail at large signal and non-linear situations which actually are of equal occurrence in design. For instance they won't help you at all designing a class D or class S amplifier. Nor much for digital design.
?-)
I have done so twice. Once on my own work for my edification (a waste of time), and once for work when i didn't have spice to do the work for me (rather painful and marginally worth it). Both were long ago.
?-)
had
Ifor practical purposes the ac-current gain and so-called static current gain are identical. This follows because IC in ratio to IB by factor hFE makes deviation in IC, ic, to deviation in IB, ib, that same ratio, of hfe=hFE. This is why the only distinction between hFE and hfe is one of analytical notation, and /also/ why the datasheet specification is so widely used for both. And this has nothing to do with hFE variation with VCE, Early effect, and level of current injection IB.
John
the
distinct somehow.
numerically.
range with guardbanding and, hopefully a 'typical' hFE variation with IC,Q. The hfe whenever presented are usually typical, at fixed IC,Q and VEC,Q and freq, and should be larger than hFE at Q-point because it doesn't have to contend with that small cut-in region where hFE trends to 0.
mentally computing a hybrid-pi. The BE diffusion capacitance can be a biggie with finite source impedance drive, and, God forbid, you might even use Miller's Rule here and there to do a quick estimate of bandwidth and rise times.
Most apps just need a voltage and beta at some current. Sometimes power dissipation is an issue, thetas and stuff. Bipolars are too slow for anything interesting.
-- John Larkin Highland Technology Inc www.highlandtechnology.com jlarkin at highlandtechnology dot com Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom timing and laser controllers Photonics and fiberoptic TTL data links VME analog, thermocouple, LVDT, synchro, tachometer Multichannel arbitrary waveform generators
Yep. I was already building circuits that "worked", BEFORE I went off to M.I.T. My M.I.T. course-work provided the analytical tools to hone my capabilities. ...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 http://www.analog-innovations.com | 1962 |
I love to cook with wine. Sometimes I even put it in the food.
distinct somehow.
current.
Nope, noise cancellers are sensitive to the difference between h_FE and h_fe at a single value of collector current.
The reason is that the balance criterion is a DC value, but it's the fluctuations that we want to have cancel. See Eq. 10 in my paper, "Ultrasensitive Laser Measurements Without Tears",
Cheers
Phil Hobbs
-- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics 160 North State Road #203 Briarcliff Manor NY 10510 hobbs at electrooptical dot net http://electrooptical.net
Mentoring is very important, but so is analysis.
My son Simon interned with me this summer. I also visit universities periodically, but my main way of doing that is in print.
Cheers
Phil Hobbs
-- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics 160 North State Road #203 Briarcliff Manor NY 10510 hobbs at electrooptical dot net http://electrooptical.net
I have often offered a "drop by" invitation. Anyone who wants to come and look over my shoulder is welcome... just advise when, I may be out-of-town. ...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 http://www.analog-innovations.com | 1962 |
I love to cook with wine. Sometimes I even put it in the food.
On Wed, 17 Oct 2012 11:43:48 -0400, Phil Hobbs wrote: [...]
But analytical abilities can also sure be mentored :)
Reading can not just compare with mentoring.
On Wed, 17 Oct 2012 09:12:48 -0700, Jim Thompson wrote: [...]
Really, I think I will have a bout of depression :( I was to go to Queens University of Belfast, Northern Ireland, for an M.Sc. in Opto-elec, but was denied visa (potential immigrant), in 1995. In those days in India you could never have the best education money could buy. Privatisation of education has picked up since the 2000's, but is in no way encouraging like the west. Talking to you guys, and such prospects of mentoring?! Oh, God! Why I am a third-world citizen!
Have posted combined replies to PH's post and yours
Optoelectronics? Read Phil's book. If you can't get a copy, let me know and I'll send you one.
-- John Larkin Highland Technology, Inc jlarkin at highlandtechnology dot com http://www.highlandtechnology.com Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom laser drivers and controllers Photonics and fiberoptic TTL data links VME thermocouple, LVDT, synchro acquisition and simulation
How much do you charge for that service?
I think its too late for an Indian (never late for a US citizen :) ) . Priorities and realities have changed. But thanks for your nice gesture.
What I meant was, if you are giving them away, I want one.
Order one from Amazon. I offered one to Rajib on the condition that he couldn't get one easily himself.
-- John Larkin Highland Technology Inc www.highlandtechnology.com jlarkin at highlandtechnology dot com Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom timing and laser controllers Photonics and fiberoptic TTL data links VME analog, thermocouple, LVDT, synchro, tachometer Multichannel arbitrary waveform generators
On Fri, 19 Oct 2012 09:04:29 -0700, John Larkin wrote: [...]
Dear JL, The book,"All New Electronics Self-Teaching Guide" by Harry Kybett & Earl Boysen is precisely the book I have been looking for. The chain that began with my choice to do something about my ignorance in the history of computing led me here, and you all have led an active role in making me reach here. I have also ordered "electronics designs manual" by Markus and hope to use it for analysis. I choose this precise circumstance, when one man extends his hands to the other in pure benevolence, feeling good about it and expecting nothing in return, to thank you all. My best regards
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