bias voltage independent with temperature

[gavanbash]

bias voltage indpendant with temparature

Hi
I'm using this circuit in order to stable bias voltage from derivation with temperature as Daivid Jones in analog circuits design said.
In order to making stable all of gm transistors in folded cascade opamp I'm using this circuits. Does it true?
My simulation results show another thing in the circuits.
How can I make all gm and gds stable versus temperature and process variation?
Thanks alotView attachment RFFlow - (Untitled).pdf

 

[dick_freebird]

Re: bias voltage indpendant with temparature

These parameters naturally want to wander with PVT.
you might stabilize them for one "magic point" (though
not likely both at once) but whether these are the key
to overall temperature stability of the output voltage,
I rather doubt.

More likely to make a manufacturable (P-insensitive)
product with desirable regulation accuracy (V- and T-
insensitive) you will need high quality amplifiers (V)
and two trims (T, P). If your accuracy requirements
are in the 5% or looser range then maybe you can get
to an untrimmed reference. But power supply or data
acq grade, plan on trimming and its associated chip
area and test costs (not to mention the adventure
of test development allowing you to cleanly measure
a good reference, better than its required tolerance.

 

[d123]

Re: bias voltage indpendant with temparature

Hi,

Not sure if "FIGURE 10. Basic constant gm reference" and/or "FIGURE 11. Modification of constant gm reference to eliminate error due to body effect" could be of any use to you for a part of your requirements.

 

[gavanbash]

Re: bias voltage indpendant with temparature

Thank you
You saved my time.
with best wishes