I´m sorry, I was not very clear before. I was more interested in differential pairs, I have seen different architectures where the gate of the biasing transistor is sometimes a dc voltage and sometimes a current source.
I´m sorry, I was not very clear before. I was more interested in differential pairs, I have seen different architectures where the gate of the biasing transistor is sometimes a dc voltage and sometimes a current source.
If you use resistor, the tail current will be variable with temperature and bias condition of the pair transistors and also a voltage drop will occur across the resistor for nothing.If you use a current source, it will be independent from temp. and any extra voltage drop won't occur..
If you use resistor, the tail current will be variable with temperature and bias condition of the pair transistors and also a voltage drop will occur across the resistor for nothing.If you use a current source, it will be independent from temp. and any extra voltage drop won't occur..