Patent ID: 8035450
Filing Date: 2011-10-11
Classification: H03F

Abstract:
1. An operational amplifier, comprising: a first amplification stage having an input terminal structured to receive a signal to be amplified, and a first output terminal; a second amplification stage having a first input terminal connected to the first output terminal, and an output terminal structured to provide the amplified signal, the first and second amplification stages defining, between the input terminal and the output terminal, a signal transfer function having a first pole and a second pole; and a decoupling stage having a further input terminal connected to the first stage input terminal, and a further output terminal connected to the second stage output terminal, the decoupling stage structured to introduce at least one zero in the operational amplifier transfer function, the decoupling stage having an electronic follower device connected between a ground terminal and a bias terminal and provided with a further input terminal connected to the input terminal of the first stage, the follower device structured as a source follower that is connected to the bias terminal through a bias transistor.