Electronics tutorial - The Darlington and Sziklai transistor configurations

#83 In this video I look at the two basic high gain transistor configurations the well known Darlington and the less well known Sziklai. I mean you probably used the Sziklai in the past just didn't know the name.
Links:
Patents:
patents.google.com/patent/US2...
patents.google.com/patent/US2...
Datasheets:
www.onsemi.com/pub/Collateral...
www.onsemi.com/pub/Collateral...
assets.nexperia.com/documents...
www.onsemi.com/pub/Collateral...
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[@carpenter123154]

Excellent tutorial!

[@Virtueman1]

Great teaching on this channel. You taught me LTspice. Always fast and without unnecessary fluff.

[@FesZElectronics]

I'm happy you are enjoying the videos! Thank you!

[@maxpetrelli2142]

As usual, excellent educational video! Thanks.

[@mohamedtebbo6095]

I hope you get all the subs you deserve!! Good work my friend 👏

[@gkdresden]

The main advantage of the Sziklai design is its lower base to emitter voltage of only 0.6 to 0.8 V. So in audio amplifier configurations you can get with your output signal closer to to the power rails. So at +/- 12 V you will get with Darlingtons about 10 to 11 W of output power at 4 Ohm impedance. with Sziklais you can get 13 to 14 W under the same conditions and the heat produced by the output transistors is considerably lower at full power.

[@wilmdrdo1228]

Please do a tutorial about negative feedback.

[@willemhekman1788]

Super explanation, thank you!

[@hugoribeiro8281]

What a nice video! very good explanation. In some old projects it is common to see only the NPN 2N3055 in the output stage: Darlingron in the positive line and Sziklay /CFP in the negative line. Nowadays its very common to see two complementary feedback pairs, CFP in the amps output 😀. Some measurements shows that its the better solution for THD. I never have used this configuration... maybe in the future 😉. Once again, thank you 😉👍

[@FesZElectronics]

That was really the main reason I insisted on using 3055 related transistors - for quite some time it was the only power transistor available. I have also seen the same thing in the old books - power amplifiers being built with 2n3055 based push pull stages. I guess the more symmetrical the output stage is, the better for it will behave from a distortion point of view.

[@ladronsiman1471]

It is funny that Darlington promoted the idea of having both transistors in the same package and this is how you find them ..And Sziklai didnt and you have to do arrange that configuration with discrete parts..

[@FesZElectronics]

I was not aware of this, its an interesting piece of information! I guess considering the way in which transistors are made, its easier to have 2 of the same kind on the same substrate, than to have 2 different ones.. especially in the early days of transistor manufacturing it would have been far more difficult to construct a Sziklai configuration...

[@0MoTheG]

Great gain, terrible transition frequency

[@FesZElectronics]

You win some, you loose some :D

[@0MoTheG]

@@FesZElectronics It used to be common practice to not just use low gain power BJT but also to brute force base current into RF BJT to operate them at low current gain.