What is an amplifier
An amplifier is a device that makes a small signal bigger by using power from a batter
Where does this power in amplifier come from
DC supply
What are the matching conditions for maximum voltage gain
- Large input resistance ( Rin > R s )
- Smaller output reistsance ( Rout < RL )
Write down the basic formula for overall gain and in dB
Overall Gain=VS/ VL
dB=20log10(V2/V1)
What is efficiency η
Efficiency refers to the ratio of the useful power that goes to the load and the power that is wasted as heat.
η=PL/PDC×100%
What is the difference between single ended and differential ports
single ended - one side is connected to ground
differential - neither side is connected to ground
What is a bode plot and what features does the bode plot of a typical amplifier have
- This is a plot of Gain (dB) against the logarithimic frequency
- Shaped as a trapezium
- Lower cut-off frequency and higher cut-off frequency at -3dB
- Contains bandwidth
What are some clues for cascaded systems in questions
- Seeing different stages between the source and load in a circuit
Write down the equations we use for cascade systems
G1 * G2 * Rin(1)/ Rin(1) +Rout(2) or vice versa
