Gain Bandwidth product

[joehwang]

Hi,

I have a question when design a two-stage op-amp (include miller cap and Rz)

I am improving the Gain Bandwidth product(GBWP).
If the Power(DC) for the circuit is 883uW, and the Vdd=1.8v, the Load is CL=0.3p,
What is the maximum GBWP I can get? Is there anyway to know the maximum?

Thanks!

Wang

 

[yxo]

For output stage often take 0.5 part of all current budget. For input stage 0.1 part of current budget. Then for 0.3pF you Cc will be =0.22*0.3p. then
GBWP = gm1/2pi*Cc
where gm1 - transconductance of input pair