Patent ID: 7245189
Filing Date: 2007-07-17
Classification: H03F,H03G

Abstract:
1. A grounded input active cascode amplifier with increased gain that provides an output current to a load, said amplifier comprising: a first transistor, wherein the base terminal of said first transistor is coupled to a first supply voltage and the collector terminal of said first transistor is biased with a first current source; a second transistor, wherein the base terminal of said second transistor is coupled to the collector terminal of said first transistor, the emitter terminal of said second transistor is coupled to an error control input, and the collector terminal of said second transistor is biased with a second current source; a third transistor, wherein the base terminal of said third transistor is coupled to a second supply voltage and the emitter terminal of said third transistor is coupled to the emitter terminal of said second transistor; and a fourth transistor, wherein the base terminal of said fourth transistor is coupled to said collector terminal of said second transistor, the collector terminal of said fourth transistor is coupled to the collector terminal of said third transistor, the emitter terminal of said fourth transistor is coupled to the emitter terminal of said first transistor, said emitter terminal of said fourth transistor that receives an input signal to be amplified, and said output current being derivable from the collector terminal of said fourth transistor; and a feed forward circuit that is coupled between the base terminal of said second transistor and the emitter terminal of said first transistor.