How does impedance affect gain?
We have also seen that as the gain goes up the input impedance goes down from 15.8kΩ without it to 2.2kΩ with it. The increase in voltage gain can be considered an advantage in most amplifier circuits at the expense of a lower input impedance.
Is impedance the same as gain?
Output impedance depends on if the gain is for extra current, or for extra voltage or voltage swing. Current gain is normally taken off the emitter (of a transistor )and implies there is no voltage gain, but the drive impedance is lowered, possibly a great deal.
Is 16 or 32 ohms better?
Sound quality and impedance If we count the consumption of power, the headphones of 16 Ohm will take 2.5 mBt, while 32 Ohm – 1.25 mBt. It means that high-impedance headphones will sound quieter, but take less battery power. On the contrary, low impedance ones will sound louder and take more power from the battery.
How is current gain determined in a transistor?
This equation is transistor equations for the CE configuration. The ratio of the collector current to that of emitter current gives current gain alpha in the Common Base configuration. Similarly, the ratio of the collector current to that of base current gives current gain beta in the common-emitter configuration.
Is the current gain of a bipolar transistor constant?
It is normally expected that the value of current gain β for a bipolar transistor is constant, however there are some variations that occur in the value of β or h FE. β variations with collector current: The collector current level can cause a variation in the level of β or or h FE.
What is the current gain of a PNP transistor?
For example a BC109B has a current gain h FE between 200 and 450, and a BC109C has a current gain h FE between 420 and 800. Whatever the circuit used, and whether NPN transistors or PNP transistors are used, the current gain of the transistor is a key parameter.
What is the relation between transresistance and voltage?
Transresistance is generally used as performance coefficient that tells, how an amplifier reflects its input ac current as its output ac voltage.It can be also considered to be a characteristic of a transistor. It can describe the maximum available transresistance of a properly designed single transistor amplifier circuit at a given frequency.