In large signal analysis for Differential amplifier with current source load, how the output voltage is 0 when Vin1 is more negative than vin2 ?
Vout= Vdd- 0*ro4= Vdd
In a Differential amplifier with current source load (using current mirror), why the node P ( source node of both input transistors ) is considered approximately ac grounded in most of the books when doing small signal analysis ? I do not understand this because the circuit is not symmetrical ...
In a Differential amplifier with current source load (using current mirror), why the node P ( source node of both input transistors ) is considered approximately ac grounded in most of the books when doing small signal analysis ? I do not understand this because the circuit is not symmetrical ...
...... while looking to the right you see a bigger impedance, especially at low frequencies.hen the amplifier works, hence it is not an ac ground even for small
Sutapanaki.....please, can you explain WHY the input impedance looking into the right transistor is "bigger"?
Don`t you think, this depends on the impedance connected to the gate of this transistor?
I did not follow. With mismatch in RD, and ideal tail current source, and high frequency common mode noise ,why does not we see the disturbance on the single ended output ?
In DC and low frequencies the impedance or rather the resistance looking into the source of the right transistor is (1+rp/rn)/gm, where rp is ro of the PMOS transistor and rn is the ro of the NMOS transistor.
In a common-gate configuration with gate at ac ground, looking into the source of the transistor with the drain loaded by some resistance which is at least with the order of magnitude as ro of the transistor, the resistance is as I showed it in my previous post. This source resistance is 1/gm if drain load resistance is small or if we disregard the effect of ro of the transistor (in other words consider it infinite). I could attach a derivation of the formula if you insist,but you can find it also in any book on analog transistor design.
.
Do you speak about the diff. pair with a current source load?
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?