Table of Contents
What is a folded cascode?
Folded cascode amplifier is a single-pole operational amplifier with large output swing and has higher gain compared to the ordinary op-amp. It is very suitable for deep negative feedback because of its small signal gain that can be very large.
What is the output impedance of a transistor?
In the case of a nonlinear device, such as a transistor, the term “output impedance” usually refers to the effect upon a small-amplitude signal, and will vary with the bias point of the transistor, that is, with the direct current (DC) and voltage applied to the device.
How do you find the input impedance of a Mosfet?
IMPORTANT CASE:- Let me talk taking the gate as the input terminal of a MOSFET. So we follow the above mentioned steps to find input impedance: Here we know that the gate current(Ig) is assumed to be zero. So here Ix=Ig=0. Thus the term (Vx/Ix) tends to infinity which is the input impedance itself.
Why do we use folded cascode?
Advantages of Folded Cascode OTA It provides high output impedance which is useful in obtaining • high gain from the circuits. It helps to achieve high gain, high bandwidth and high • swing.
What is input output impedance?
BJT Amplifier Input/Output Impedance Input impedance is defined as the ratio of imput voltage to input current. It is calculated from the AC equivalent circuit as the equivalent resistance looking into the input with all current cources replaced by an open and all voltage sources replaced by a short.
How do you find the input impedance?
The generalised formula for the input impedance of any circuit is ZIN = VIN/IIN. The DC bias circuit sets the DC operating “Q” point of the transistor and as the input capacitor, C1 acts as an open circuit and blocks any DC voltage, at DC (0Hz) the input impedance (ZIN) of the circuit will be extremely high.
What is the output impedance of a MOSFET?
3: Output Impedance. The derivation of output impedance is unchanged from the JFET case. From the perspective of the load, the output impedance will be the drain biasing resistor, RD, in parallel with the internal impedance of the current source within the device model.