Hello, I am hoping someone could help me with part B of this problem. I am not sure of the effects the resistor would have on the differential output gain.
Also I have attached my solution to part A but I am uncertain if I derived it correctly.
Any help would be appreciated !
b. A resistor between outputs acts in parallel with (Rc + Rc), so reduces gain by that amount. No effect on CM.
Tim
Thanks Tim !
I've attached my proof for b. Does this look OK ?
Also, I thought the added resistor would affect Vo1, so why would there be no effect on CM gain ?
b. A resistor between outputs acts in parallel with (Rc + Rc), so reduces gain by that amount. No effect on CM.
With common mode gain they mean the gain for a single ended output (not the differential gain with transistor mismatch as is common). Because of Ree this will change.
Hmm, it should be 3, not 4.
What is the definition of differential output voltage? Common mode?
Tim
delta[Vout(diff)] = delta [Vout(1) - Vout(2)]
delta[Vout(cm)] = (1/2) x delta[(Vout1 + Vout2)]
I've attached my proof for b. Does this look OK ?
No - it doesn`t.
You have forgotten that the third (new) resistor is not at signal ground at one leg.