如右圖MOSFET電路，|Vt| = 1 V、μn Cox = 20 μA/V²、μp Cox = 10 μA/V²，若V1 = 6 V、V2 = 2 V，則(W/L)_M1 ∶ (W/L)_M2 ∶ (W/L)_M3 為何？（忽略通道長度調變效應）

正確。串聯三管電流相同。設Id=(1/2)μCox(W/L)Vov²。M1(PMOS):μpCox=10、|Vov|=3→Id=(1/2)(10)(W/L)1(9)=45(W/L)1；M2(NMOS):μnCox=20、Vov=3→Id=(1/2)(20)(W/L)2(9)=90(W/L)2；M3(NMOS):μnCox=20、Vov=1→Id=(1/2)(20)(W/L)3(1)=10(W/L)3。令三者相等：45(W/L)1=90(W/L)2=10(W/L)3，化簡得(W/L)1:(W/L)2:(W/L)3=2:1:9。