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26th April 2019, 00:38 #1
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Constantgm bias circuit
For https://designersguide.org/forum/At...amp.pdf#page=3 , how to derive expression (14) ?

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5th May 2019, 09:08 #2
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Re: Constantgm bias circuit
Do you guys know how to come up with the equation for R_{DS4C} ?

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6th May 2019, 09:59 #3
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Re: Constantgm bias circuit
I got a different answer, maybe I made a mistake in the derivation but you can check to see if it's right though.
edit:
Oh I see my mistake now, when I absorbed (W/L)4c into the square root I forgot to square it. and (W/L)4c=P/M * (W/L)2E which would make
Rds=[2uCox(P/M)^2(W/L)2E*ID]^1/2 which would equate to gm2E^1/2 * M/PLast edited by rmanalo; 6th May 2019 at 10:07.
1 members found this post helpful.

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6th May 2019, 14:33 #4
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Re: Constantgm bias circuit
Thanks. Could you rewrite the correct solution ?
I am having problem following your derivation (with mistake).

6th May 2019, 16:36 #5
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7th May 2019, 01:38 #6
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Re: Constantgm bias circuit
Besides P, the M should have been squared inside the square root. I think you forgot it.
I do not understand why gm4e is always independent of process, temperature and load variations ?
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