iamxo
Full Member level 4
- Joined
- Mar 22, 2006
- Messages
- 225
- Helped
- 16
- Reputation
- 32
- Reaction score
- 4
- Trophy points
- 1,298
- Location
- Southeast Asia
- Activity points
- 2,493
op amp scaling
when I do scaling of opamp in MDAC, such as the sampling capacitor, input transistor size, tail current, the GBW is much less than that of the original opamp.
However, in theory, gm is scaled the same as the load capacitor, so the GBW(gm/CL) will keep constant. If i want to increase the GBW of the scaled opamp, the tail current is increased much, which cause large power consumption.
So, i can not understand which caused this. Anyone meets the same problem?
thank you in advance.
when I do scaling of opamp in MDAC, such as the sampling capacitor, input transistor size, tail current, the GBW is much less than that of the original opamp.
However, in theory, gm is scaled the same as the load capacitor, so the GBW(gm/CL) will keep constant. If i want to increase the GBW of the scaled opamp, the tail current is increased much, which cause large power consumption.
So, i can not understand which caused this. Anyone meets the same problem?
thank you in advance.