Patent ID: 7154333
Filing Date: 2006-12-26
Classification: H03F

Abstract:
1. An amplifier comprising: a first voltage source; a first operational amplifier coupled to said first voltage source; a second operational amplifier coupled to the output of said first operational amplifier; a first NPN transistor and a first PNP transistor coupled to an output of said second operational amplifier, said first NPN transistor and said first PNP transistor coupled back to back; a second PNP transistor, the base of said second PNP transistor coupled to the collector of said first NPN transistor; a second NPN transistor, the base of said second NPN transistor coupled to the collector of said first PNP transistor; a third NPN transistor, the base of said third NPN transistor coupled to the collector of said second PNP transistor; a third PNP transistor, the base of said third PNP transistor coupled to the collector of said second NPN transistor; a voice coil, wherein the emitters of said first NPN transistor, said first PNP transistor, said third NPN transistor, and said third PNP transistor are coupled to the input of said voice coil; and a resistance, said resistance coupled to the output of said voice coil and the negative input terminal of said first op amp.