Mirror model for designing a continuous-time filter with reduced filter noise

摘要

A current mirror model is provided for designing a continuous- time filter with reduced filter noise. The current mirror model includes an input branch having a voltage V.sub.in across a series circuit including a voltage source and a resistor of resistance value R.sub.m. The voltage source has a voltage value substantially equal to the value 4kTR.sub.m, where k is the Boltzmann constant and T is the temperature. An output branch is coupled to the input branch. The output branch has a first current source and a second current source. The first current source is controlled by the voltage V.sub.in and sources a current substantially equal to a transconductance G.sub.m of the output branch times the voltage V.sub.in. The output branch transconductance G.sub.m has a transconductance value substantially less than a value of an input branch conductance 1/R.sub.m. The second current source, coupled in parallel to the first current source, sources a current substantially equal to the value 4kTG.sub.m.