Biasing a diode with which source?

[MobiNaz]

Hi all,

I want to bias a diode at knee point. I know its IV curve (that its knee V and respective I ) . My concern is should I ensure knee voltage by biasing it with voltage source or knee current that is biasing by current source.

Thanks in Advance

 

[VSMVDD]

knee is a hystric component {internal}

you should know the spec of the diode and work out where the knee node will be
it has to exist as the right part of the layer and is tunable by its bias point dif to zero potential ... at point place voltage

1V=((PPV)*(((1*Vp)/(A*K))I))

V voltage foward...
I current
A anode potential
K kathode potential
VP voltage proportion
PPV point place voltage


so now to the question

its simple
avoid a big node of current or voltage across the barrier

or it breaks down faster or very fast

infact move all nodes for current to a load resistor

and voltage to a resovoir cap ...

simple...

minimise the knee current node if you have to use its schmit point
do it and use a faster barrier diode instead,,, by 1/ magnitude of its foward current...

 

[MobiNaz]

Perhaps my question was not clear. The thing is I need to bias a diode at knee voltage or threshold say 0.7 V (at the point of maximum non linearity) I know the the voltage and I values say 0.7 V and 0.14 mA respectively (that is the knee threshold V and respective I).

Now should I provide a voltage source of 0.7 V and monitor the current not to exceed a max value that the diode can sustain?OR
Provide Current of 0.14 mA via a resistor and monitor V.

Which method is best.

I believe both will work as I know I and V. 2 nd method is preferred when we do not know the knee voltage.

What do you say?

 

[erikl]

Current mode.

 

[chuckey]

use the current mode, say 12V with a (12-.7)/.14 K resistor in series (~8K?).
Frank

 

[MobiNaz]

By why? I am after valid arguments with references?

 

[MobiNaz]

I got the reference

See book: Microelectronic Circuit, Adel S. Sedra, Kennith C. Smith , pages 150-151

Thanks everyone for helping...

 

[enjunear]

By why? I am after valid arguments with references?

Reference: just about any semiconductor physics textbook. Diodes are current-controlled devices, so it is inherently logical to use the measure by which they are defined (I), rather than a measure that is derived (V).