[AMPS] bias regulator

[rich]

>
>Xicor has introduced a Bias regulator chip made especially for use 
>with LDMOS RF transistors. It uses active feedback from a drain 
>current sensing resistor, to adjust the gate bias to keep the part at 
>optimal Q point for, say, class AB1 idling current. It has an 
>interface port for digital control, to force it into various states 
>such as active adjusting, PA shutdown, PA transmit without 
>adjustment, etc. Internally the chip uses one of their digital 
>controlled potentiometers to make the adjustment, and has an 
>instrumentation amp front end, an error amp and an output buffer amp. 
>Its the X9470. Heres the blurb from their website. There is a PDF 
>file press release but no datasheet that I could find:
>
>>Xicor and Motorola Collaborate
>>                   On "Smart Biasing" Solutions for RF Power Amplifiers
>>
>>                   MILPITAS, California - January 16, 2002 - Xicor, 
>>Inc. (Nasdaq/NMS: XICO)
>>                   announced today that they have teamed up with 
>>Motorola to provide radio
>>                   frequency power amplifier (RFPA) reference 
>>platforms for GSM, EDGE and
>>                   W-CDMA cellular basestation applications. These 
>>reference platforms will
>>                   incorporate Xicor's unique "Smart Biasing" ICs for 
>>RFPA applications.
>
>
>All the ricka-racka on screen voltage regulators for tetrodes 
>reminded me to point out that the IC folks have it easy to build it 
>all into a small ASIC device, while we tube types gotta fool around 
>with MOSFETS, Zeners, spark gaps, and so on, to stabilize our beloved 
>bottles. It sure would be wonderful if hams with huge egos would grow 
>up and keep their contributions to AMPS@CONTESTING.COM at a 
>technical, not personal, level.

//   I view ad hominem attacks as good news.  There's usually a tender 
nerve behind technical bull's-eyes.   Eliminate the "expert" 
technoblatherers on AMPS and the group would likely be a sure cure for 
insomnia.  

> Its amazing how quickly the 
>discussions seem to elevate to attack mode. 

//    As a wild and crazy guess, the problem might be related to 
testosterone.  
-  In some primative tribes of New Guinea, men wear phallocarps -- i. e., 
holsters used to protect male equipment from thorns and brambles on 
jungle trails.  
-  See  *Discover* magazine, "April, 1985.pp,70-83 - "Everything Else You 
Always Wanted to Know About Sex . . . But That We Were Afraid to Ask".  
by Jared Diamond:
quoting:
" ...   Phallocarps vary in length (up to two feet), diameter (up to four 
inches), shape (curved or straight),  ... ... ...   Each man has a 
wardrobe of several sizes and shapes. Western male anthropologists 
interpret the phallocarp as something worn for modesty or concealment, to 
which my wife had a succinct rebuttal:  "The most immodest display of 
modesty I've ever seen!"

>I'm sure certain individuals will send me a stab for suggesting that, but 
.... just 
>grow up.
>
//  My favorite kvetcher is the guy who complains about reading my 
replies. 

cheers, John

-  R. L. Measures, a.k.a. Rich..., 805.386.3734,AG6K, 
www.vcnet.com/measures.  
end


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