Amplifying circuit having supplemental transconductance and stable common-mode feedback

Abstract

An amplifying circuit allows its loading circuit to contribute a transconductance to increase the bandwidth of the amplifying circuit, and thereby achieves common-mode stabilization. The amplifying circuit includes a first and a second amplifying circuit. The first amplifying circuit is coupled between a high-voltage terminal and a low-voltage terminal, and outputs a first amplified signal according to an input signal. The second amplifying circuit includes: an input-stage circuit configured to receive the input signal and output an input-stage output signal to intermediate nodes; a transconductance and loading circuit coupled between the high-voltage terminal and the input-stage circuit, and configured to output a transconductance-enhancement signal to the intermediate nodes according to the first amplified signal; and an output-stage circuit coupled between the high-voltage terminal and the low-voltage terminal and coupled to the intermediate nodes, and configured to output an output signal according to the input-stage output signal and the transconductance-enhancement signal.

Dependencies are inferred from the claim text.