gaom9
Full Member level 4
Hi,
I want to know how to calculate the resistor to ground when calculate the POLE and ZERO.
I saw some examples about it, but in some node, I can not find the resistor to ground in small signal model.
And when calculate it, should we short the input and output to ground?
Is there any books about it, please?
For example, when I calculate the POLE and ZERO of the common-gate amp as shown below. What is the resistor of note X to ground? in its small signal as shown below, Rs and 1/gm//1/gmb is in series, but both of them do not connect to ground, but in Razavi is book, the resistor of it to ground is RS//[1/(gm+gmb)], why? and also the question to note Y.
And should we short the output and input to ground when calculate?
common gate amp
small signal model
Thank you.
Best regards!
I want to know how to calculate the resistor to ground when calculate the POLE and ZERO.
I saw some examples about it, but in some node, I can not find the resistor to ground in small signal model.
And when calculate it, should we short the input and output to ground?
Is there any books about it, please?
For example, when I calculate the POLE and ZERO of the common-gate amp as shown below. What is the resistor of note X to ground? in its small signal as shown below, Rs and 1/gm//1/gmb is in series, but both of them do not connect to ground, but in Razavi is book, the resistor of it to ground is RS//[1/(gm+gmb)], why? and also the question to note Y.
And should we short the output and input to ground when calculate?
common gate amp
small signal model
Thank you.
Best regards!
