Amplifiers (group)

Amplifiers (group)

1. Electronic device that increases the voltage, current or power of a signal.

2. Kind of uses

   • Wireless Communication
   • Acoustic pickups
   • Audio equipment
   • Boardcasting

3. Classification

   • Weak-signal amplifier
   • Power amplifier

4. Characheristic

   • Gain
     • Increase in signal power
     • Symbolized with letter 'A', and expressed in decibel
   • Bandwidth
     • Range of frequencies for which the amplifier gives "satisfactory performance"
   • Efficiency
     • Amount of powersource usefully applied to the amplifier's output

5. Inconvenience

   • Noise and distorsion
     • Unwanted signal that degrade the desired signal content in the system
     • Negative feedback to avoid these problems
     • 2 types
       • noise generated by the system itself
       • noise recived in the input

6. TYPES

   • Linear
     • The output must be a faithful reproduction of the input
     • Radio frequency power amplifier
     • Output proportional to input but it delivers more power into a load
   • Audio
     • Used in loud speakers
     • Amplify low power audio signal
   • Differential
     • Amplify the difference between two voltages
     • OPERATIONAL AMPLIFIERS
       • High -gain class
       • Electronic feautures
         • High input impedance Low output impedance High open-loop gain
       • Construction
         • Integrated circuit (IC)
           • 2 input pins - 1 output pin - 2 supply pins - 2 offset regulation pins
       • Pros
         • Low cost Versitale High performance