Multistage amplifier

For many applications, the performance obtainable from a single-stage amplifier is often insufficient , hence several stages may be combined forming a multistage amplifier. These stages are connected in cascade, i.e. output of the first stage is connected to the input of second stage, whose output becomes input of third stage, and so on. For many applications, the performance obtainable from a single-stage amplifier is often insufficient , hence several stages may be combined forming a multistage amplifier. These stages are connected in cascade, i.e. output of the first stage is connected to the input of second stage, whose output becomes input of third stage, and so on. The overall gain of a multistage amplifier is the product of the gains of the individual stages (ignoring potential loading effects): Alternately, if the gain of each amplifier stage is expressed in decibels (dB), the total gain is the sum of the gains of the individual stages: