Hi, What is the output impedance seen at the drain of the third transistor in the below figure.
Should Rout3 > Rout2 ? at DC and at higher frequencies, for example 50GHz
The problem I have is that when I have just a cascode connection, the circuit is stable but when I connect 3 or 4 transistors in the stack it is not stable anymore. The reason I see is the real part of output impedance of the stack is negative.
The problem I have is that when I have just a cascode connection, the circuit is stable but when I connect 3 or 4 transistors in the stack it is not stable anymore. The reason I see is the real part of output impedance of the stack is negative.