What are the advantages and the inconveniences to use the amplifiers of class D in front of the other technologies?
Class
A
B or AB
C
D
Advantages
An alone transistor almost void distortion
2 transistors performance established between 0,6 et 0,7
An alone transistor performance> 0,7
2 or 4 transistors functioning in “all or nothing”, high performance> 0,9 little weigh
Inconveniences
Poor performancepermanent consumption
Assembly « push pull » with distortion and point of rest difficult to determine
Utilization of a narrow band few optimal
Necesita un filtro de salida pasivo elaborado, distorsión poco optiman
Applications
Amplifier of little power (<1 W)
Amplifier of audio, flat of gone out of AOP
Selectiveamplifiermultiplier
MultiplieroffrequencyNeeds a passive elaborated filter of exit, distortion
In spite of the implied complexity, a class D amplifier been looked after well offers the following advantages:
Reduction in cutting and weight of the amplifier,
The less loss of power thanks to the excellent class D,
The less price of in dissipator of heat and the more compact circuits,
Return on conversion of power more important, often upper to 0,9 (upper return has that of the class B and AB (between 0.6 and 0.7) which are also used in the audio amplifier).
Level reduction of noise produces at the time of the change of state of the switch which, in certain assemblies, can interfere with the functions(offices) RF as a mobile(portable), GPS or the reception FM of one radio.