Positive SSL
1 有一運算放大器,若 CMRR = 80dB ,Ad = 4500 ,Vi(+)=0.5mV ,V(i-) = 0.45mV ,求 Vo ?
A 200mV
B 225mV
C 250mV
D 300mV

CMRR = `20 log ((Ad)/(Ac))`

80 = `20 log ((4500)/(Ac))`

4 = ` log ((4500)/(Ac))`

10000 = `(4500)/(Ac)`

Ac = `4500/10000`

Ac = 0.45

Vo = Ad Vd +Ac Vc

= 4500 * (0.5m-0.45m) +0.45 * `(0.5m+0.45m)/2`

= 4500 * 0.05m +0.45 * 0.475m

= 4500 * 0.05m +0.45 * 0.475m

= 225m +0.21m

≒ 225mV