An amplifier converts a low voltage or power into a higher voltage or power signal. Different types of amplifiers and different formats are available depending on the applications required.

The high-voltage amplifiers, with bandwidth from DC  to few MHz, allow getting at the output stage, voltages of several hundreds of volts. This is called High Voltage amplifiers.

Power amplifiers, low frequency, a few MHz maximum, are generally used to stimulate inductive loads, and are driven in voltage or current as required. These amplifiers deliver a few hundred watts to several kilowatts in loads often with very low impedance.

RF power amplifiers (RF) are amplifiers that convert a low power RF signal into a higher power signal. In general, RF power amplifiers are used in ultrasonic applications to drive piezoelectric sensors, or UHF / VHF transmitter antennas.

The main parameters of the amplifiers are gain, output power, bandwidth, power efficiency, linearity (low signal compression at rated power), adaptability to output impedance, and Heat dissipation.