How to generate bias voltage for OpAmp...

[firsttimedesigning]

I am looking for a circuit that can generate the bias voltage for the opamp that I have designed...so far that circuits I have looked at are either supply or temperature dependent...is there any circuit out there that does not use diode and can generate the bias voltage for opamp?

 

[lladnar23]

You can use a peaking voltage ref (check G&M) or you can use a VT reference from the MOS Threshold voltage.

 

[firsttimedesigning]

thank you for replaying...but i dont see any peaking voltage ref...the only thing i saw is peaking current ref...maybe i can get the voltage that i want by putting a resistor on top of M2 but the thing i am worried about is that when i fabricate the chip, the resistor might have a 20% error in the resistance.....

 

[lovexxnu]

Why do you need the bias voltage?

bias current is OK, what you truely need is just current.

 

[lladnar23]

Sorry - I meant to say peaking current reference.
You're correct that you might see some process spread if you use something like a resistor. You could get around that by biasing with an off-chip resistor, if that is an option.