How to bias a CS mosfet

................like going around looking for arguments to pick.

So where's all the horseshit come from then?!

Lets see you design a circuit for the OP who hasn't specified much other than wanting to use source degeneration to stabilise Vd at 1/2 Vdd.

Well get to it Mr Blowhard - you do after all claim to be a professional circuit designer.

All spin - how do you know your design will work on the OP's application when the only data given was the requirement to use source degeneration to stabilise Vd at 1/2 Vdd.

Anyway, the OP asked the question and hasn't been back since - probably thought you'd start on them next!

I bow to your experience.

On Thu, 04 Aug 2011 13:55:44 -0500, John S wrote:

--- After having read his query again, a couple of times, it seems to me that he got precisely what he asked for and was going to use Vcc and Vcc/2 in another circuit, like this:

Version 4 SHEET 1 880 680 WIRE -112 -96 -208 -96 WIRE 80 -96 -112 -96 WIRE 224 -96 80 -96 WIRE 528 -96 224 -96 WIRE 224 -80 224 -96 WIRE -112 -32 -112 -96 WIRE 224 32 224 0 WIRE 224 32 0 32 WIRE 224 48 224 32 WIRE 368 48 224 48 WIRE 224 64 224 48 WIRE 368 80 368 48 WIRE 80 112 80 -96 WIRE 528 112 528 -96 WIRE -112 128 -112 48 WIRE 48 128 -112 128 WIRE 176 144 112 144 WIRE 0 160 0 32 WIRE 48 160 0 160 WIRE -208 192 -208 -96 WIRE -112 192 -112 128 WIRE 368 192 368 160 WIRE 480 192 368 192 WIRE 0 208 0 160 WIRE 224 208 224 160 WIRE 368 224 368 192 WIRE -208 336 -208 272 WIRE -112 336 -112 272 WIRE -112 336 -208 336 WIRE 0 336 0 272 WIRE 0 336 -112 336 WIRE 80 336 80 176 WIRE 80 336 0 336 WIRE 224 336 224 288 WIRE 224 336 80 336 WIRE 368 336 368 304 WIRE 368 336 224 336 WIRE 528 336 528 208 WIRE 528 336 368 336 WIRE -208 400 -208 336 FLAG -208 400 0 SYMBOL voltage -208 176 R0 WINDOW 3 24 104 Invisible 0 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR Value PULSE(0 30 0 1 0 1.5) SYMATTR InstName V1 SYMBOL Opamps\\LT1037 80 80 R0 SYMATTR InstName U1 SYMBOL res -128 -48 R0 SYMATTR InstName R1 SYMATTR Value 10k SYMBOL res -128 176 R0 SYMATTR InstName R2 SYMATTR Value 10k SYMBOL nmos 176 64 R0 SYMATTR InstName M1 SYMATTR Value IRF7468 SYMBOL res 208 -96 R0 SYMATTR InstName R5 SYMATTR Value 1000 SYMBOL cap -16 208 R0 SYMATTR InstName C1 SYMATTR Value 10µ SYMBOL res 208 192 R0 SYMATTR InstName R3 SYMATTR Value 500 SYMBOL nmos 480 112 R0 SYMATTR InstName M2 SYMBOL res 352 64 R0 SYMATTR InstName R4 SYMBOL res 352 208 R0 SYMATTR InstName R6 TEXT -192 368 Left 0 !.tran 1

-- JF

What's the UK equivalent of the seventh grade? Lower fourth form? The schoolyard behaviour seems to be the same, anyway. You guys sometimes have something interesting to talk about, but this isn't it.

Cheers

Phil Hobbs

You could be right. Your guess is as good as mine. Too bad he hasn't been back to give more information.

('Scuse the LTSpice clip)

What do you think of this one, John. I have not addressed temperature, but in all other respects, it complies with the OP's requirements, I think.

If not, let me know.

Version 4 SHEET 1 1132 680 WIRE 208 -288 -80 -288 WIRE 288 -288 208 -288 WIRE 368 -288 288 -288 WIRE -80 -240 -80 -288 WIRE 208 -240 208 -288 WIRE 368 -240 368 -288 WIRE 368 -144 368 -160 WIRE 208 -96 208 -160 WIRE 208 -64 208 -96 WIRE 208 -64 80 -64 WIRE -80 -16 -80 -160 WIRE 16 -16 -80 -16 WIRE -80 48 -80 -16 WIRE 208 64 208 -64 WIRE -80 144 -80 128 WIRE 80 144 80 32 WIRE 160 144 80 144 WIRE 208 176 208 160 WIRE 80 208 80 144 WIRE 80 304 80 288 FLAG 80 304 0 FLAG -80 144 0 FLAG 368 -144 0 FLAG 208 176 0 FLAG 288 -288 dd FLAG 208 -96 d SYMBOL nmos 160 64 R0 SYMATTR InstName M1 SYMATTR Value IRF7468 SYMBOL res 192 -256 R0 SYMATTR InstName R1 SYMATTR Value 1k SYMBOL voltage 368 -256 R0 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR InstName V1 SYMATTR Value 1 SYMBOL pnp 16 32 M180 SYMATTR InstName Q1 SYMATTR Value 2N3906 SYMBOL res -96 -256 R0 SYMATTR InstName R2 SYMATTR Value 12k SYMBOL res -96 32 R0 SYMATTR InstName R3 SYMATTR Value 10k SYMBOL res 64 192 R0 SYMATTR InstName R4 SYMATTR Value 1meg TEXT -260 232 Left 0 !.dc v1 6 30 .001 TEXT 608 -176 Left 0 ;100*(V(d)-.5*v(dd))/v(dd) TEXT 600 -216 Left 0 ;Put this into the trace window to see %error:

--- Amazing!

I've only ever seen Hobbs make one mistake before, but it seems he's made one again, this time, by placing you several years ahead, in school, than you really are. :-)

BTW, suck on this:

news: snipped-for-privacy@4ax.com

and let us see your electronics skills in action by providing us with a schematic and a circuit description if you can, somehow, get around the two R5's

If you can, I'll apologize for being mean to you, poor baby.

If you can't, just stand there with your butt-cheeks spread apart and I'm sure someone will come along looking for that sort of thing.

-- JF

You're getting to be a worse usenet loony (& stalker) than philthy. You could set him a good example by taking your meds.

That's about as logical as Thompson's killfiling me and then complaining about what I don't post.

John

There you go again.

John