shhaha
Newbie level 6
hi all,
I am doing the design of constant current LNA independent of the process. Its structure is the common source topology and the drain voltage is fixed to 1 V while gate voltage varies with different process. But the overdrive voltage Vod=Vgs-Vth is nearly fixed for all process. In the simulation,I find the MOS drain current still changes with different corner, ex, ff: 780uA, tt: 662uA and ss: 600uA. According to MOS current equotion of saturation region MOS : I= 1/2*un*W/L*(Vod)^2*(1+lemda*Vds), the current should be nearly constant with constant Vod and Vds. So I guess some main facters related to process result in the drain current increase, could you tell me which parameter leads to the current variation for different corner?
best regards,
I am doing the design of constant current LNA independent of the process. Its structure is the common source topology and the drain voltage is fixed to 1 V while gate voltage varies with different process. But the overdrive voltage Vod=Vgs-Vth is nearly fixed for all process. In the simulation,I find the MOS drain current still changes with different corner, ex, ff: 780uA, tt: 662uA and ss: 600uA. According to MOS current equotion of saturation region MOS : I= 1/2*un*W/L*(Vod)^2*(1+lemda*Vds), the current should be nearly constant with constant Vod and Vds. So I guess some main facters related to process result in the drain current increase, could you tell me which parameter leads to the current variation for different corner?
best regards,