Common Drain Amplifier Explained

/ edmundsj
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Common Drain input resistance, output resistance, and gain, as well as why we might want to use a common-drain amplifier (a gain near 1, a small output resistance and a large input resistance).
Hope you found this video helpful, please post in the comments below anything I can do to improve future videos, or suggestions you have for future videos.

[@layanjarjoura9945]

Your videos are amazing. Keep them coming!

[@christossiantsis6309]

I have seen in books that in the analysis of the common drain amplifier a T model is used making the Vgs easier to calculate. I thought i'd suggest also that but great video, thank you!

[@matthewmurnaghan4473]

Best video I've seen on this. Made me realise how thick I was being

[@popbasic666]

Amazing Video :3

[@CuriousMotor]

Superb explanation!

[@ucanhtrannhan7558]

THANK YOU SO MUCH!!!

[@kiyoungkim3002]

It helped me a lot. Thank u

[@finnheimberg7350]

excellent explanation. just your pronounciation of Kirchhoff gave me a hadache as a German.

[@JordanEdmundsEECS]

Hehehe forgive my American accent :p

[@abdxlive]

What If We Consider Channel Length Modulation Effect?

[@ermi6880]

please add r0 in the calculation and explain...pleeeease

[@adalbertosicairos8299]

All you have to do is replace Rs with Rs//ro. It looks a little weird but since Rs and ro always share the same two nodes ie.'S' and 'gnd' they are in parallel and be combined into an equivalent resistor.

[@SampooranamSamayal]

I'm asking that vgs is dc biasing voltage .
Also one more doubt ,why you keeping a vin dc voltage in small scale analysis . That will be grounded right .

[@jjww2788]

Thank you very much!!! you are awesome!!!

[@thanapoll.849]

Can I get Vout to be negative to ground such as -20VDC and use to bias power tube. Any schematic in internet link? Thank you so the positive may be +20VDC and the negative will be -40VDC. -40 and +20 when to feed in Common drain will get -20VDC out to bias tube. Am I correct?

[@stormz4040]

Thank you

[@SAbrooadcom]

Thanks Sir 👍
It looks like source follower with Rs circuit ,CLM=0
And then Av=GM*Rout=gm*(Rs/1+gmRs)....Answer
Rout=v/I=
I+gmvgs=v/Rs
I-gmv=v/Rs
I=v(gm+1/Rs)
v/I=1/(gm+1/Rs)=
Rs/1+gmRs...Answer
2,With CLM is not equal to 0
And then Av=GM*Rout=
gm*(Rs//1/gm)/(1+gm(Rs//1/gm))....Answer

[@superdusunceler7059]

will we get the same results if there is a resistor on the drain RD?

[@pabmarpue]

you are the boss

[@JordanEdmundsEECS]

😎

[@SAIKIRAN-tb4ce]

How rout tends to 1/gm when gmrs tends to infinity

[@merveozdas1193]

Why do we get gmRs infinite?

[@whatshisname1653]

where did the (1+gmRs) come from when solving for vout/vin?

[@arjunsuresh8887]

Open the brackets on the RHS and take Vout common from both sides

[@syncprism6283]

In the equation for the gain where gm is involved, is the standard unit for gm "s (siemens)" or "mS(microsiemens)"?

[@Gaygurke]

I think its Micro as you use Microamps / Volt in generall

[@Camaraderie_8]

What if ro was also considered

[@ronnieshaddick102]

take em out back

[@niceforalgorithm7621]

Nice

[@286b9]

thx a lot m o m

[@OfficialAnarchyz]

Too bad you left out r_DS out in the explanation