Do ultra-high frequency transistor arrays work at audio rates?

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Comrade Pingu

Joined Aug 30, 2018
22
Is that a dumb question? Probably.

Anywho, I'm looking for a transistor array to use for a digitally controlled oscillator—I don't feel like matching a bunch of discrete components. They should be running around 10 Hz to 25 kHz; I'm looking at the Renesas HF transistor arrays.
 

crutschow

Joined Mar 14, 2008
27,188
Those transistors are for VHF frequencies (many tens of MHz) and are overkill for audio frequecies.
They will work at those frequencies, but all you need are standard low-frequency transistors, such as the 2N2222,

Why do you need an array?
 

Audioguru again

Joined Oct 21, 2019
3,173
Their maximum allowed voltages and currents are very low.
Their current gain is very low with a wide range.
Single transistors like 2N3904 are MUCH better.
 

PRASS

Joined Feb 22, 2018
30
Try an lm386,

Most nearly all transistors & mosfets run into the MHz range.
They also have a tendancy to fall below threshold when used on sound waves as sound is a linear wave form that sometimes has highs & lows that are too far apart for the higher frequencies that the transistors require. Crackly sound.
 

DickCappels

Joined Aug 21, 2008
7,426
About 40 years ago, before high speed op amps were developed we used arrays like that (from RCA) in broadcast and medical imaging video circuits. It was necessary for the amplifiers to handle signals down to a few 10's of Hz.

Being little tiny high frequency transistors there were some transient thermal effects like smearing of the signal when going through differential amplifiers, which required some special design considerations. I don't recall every seeing that transient thermal effect with the TO-92 packages.

Why is it that you think you will need to match transistors -maybe there is an easy way to avoid having to do that.
 

Yffig

Joined Aug 25, 2019
8
Of course, Hi Frequency BJT arrays will work at Audio frequencies....even down to DC :)
If very low noise are not a concern , differential pairs as DMMT5401, DMMT5551, MPQ3096... will do the job and may have a higher gain
MPQ3096
 

sparky 1

Joined Nov 3, 2018
540
Learn to do an in depth study of UHF transistor arrays procedures and testing, do it yourself.
The question promotes a narrative that the experience is invalid and reference to lab equipment and detail have somehow been
replaced with one line sound bites. UHF transistor arrays are available but the procedure to do the testing is
not being asked. The criteria and basis for study exists. Some of which falls into category having controversy with standard EE
along with all kinds theories that stir trouble.
 
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