Here are three of the possible configurations of the topologies.
The current-amplifier gives you more power for driving big speakers. The voltage-amplifier increases the signal / data strength. Why did you ask the question? L
is it right that voltage amplifire need high input impedance and low out put impedance? and the current amplifire need low input impedance and high output impedance.
if yes then why? then i can clear my next doubt...........please reply?
In a current amplifier, the controlled quantity is current, and the output voltages wanders around to keep current at some value fixed by either the current at the input, or the voltage at the input (actually, a transconductance amplifier.)In a voltage amplifier, the controller quantity is VOLTAGE, and the output CURRENT wanders around to maintain the output constant.
They're opposites.If you increase voltage, then current goes down. If you increase current, the voltage goes down.