OT: SOT-523 PNP Question

Sno-o-o-ort ;-)

My preferred world, at least for Analog, is BiCMOS. ...Jim Thompson

--
| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    | 
| San Tan Valley, AZ 85142   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.

Okay, so the doping gradient would actually make the EB depletion zone thicker then, which ought to increase V_CEO vs V_CBO. What accounts for the lower breakdown voltage if the doping is really the same?

The only other things I can think of push the other way--the reverse beta is a bit lower because the effective base width is wider when depleting the graded junction. The emitter leakage is beta_R times the actual base leakage current, so even if V_CES = V_EBS, V_CEO would be less than V_EBO.

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'm not sure. Been a _very_ long time since I cracked open a copy of Al Phillips' book... like maybe the mid '60's, when I had his course, taught by the author himself, at Motorola SPD. (Googling him to make sure I spelled his last name properly, looks like he went on to found Western Digital ~1970) ...Jim Thompson

--
| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    | 
| San Tan Valley, AZ 85142   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.

Posers, pretenders? :)

At least Si-PMOS isn't as bad as, say, GaAs PMOS, which as I understand it, might as well be like using toobs (N-vacuum only* ;) ).

*Some day I want a bell jar with hard-vac stuff, a bottle of hydrogen, and a proton gun, so I can try making a "P-type" tube. Guessing the performance (perveance or something equivalent, and transit time) are going to be atrocious, by approximately a factor of 2000.

(Then try it with deuterium, and see if it's even worse?)

(...Then try it with D-T mix, and a really high voltage target? :D )

Tim

--
Seven Transistor Labs 
Electrical Engineering Consultation 
Website: http://seventransistorlabs.com

wrote

and

or

effect on

frequency

Well there is epitaxial layers that have been used as active region material. Not done very frequently though, ISTR there were some issues with dopant concentration control. Or maybe i am just imagining this.

?-)

No. Just confused ;-) Expitaxy is regularly used now for collector regions. I've seen some experimentation with using it for base as well, but so far I've not seen it in a commercial release. ...Jim Thompson

--
| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    | 
| San Tan Valley, AZ 85142   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.

Synchrotrons routinely use positron fill instead of negative electrons; there's a trick with negative-work-function interaction that makes the beam easier to refrigerate, and enhances storage lifetime.

Mainly, though, this is a larger-than-a-bell-jar kind of operation.