Patent ID: 6507246
Filing Date: 2003-01-14
Classification: H03F

Abstract:
A field-effect transistor (FET) circuit having a resistor-programmable transconductance, comprising:a resistance having a value R1, first and second FETs, said resistance and said first and second FETs series-connected in sequence between a supply voltage and a circuit common point, third and fourth FETs, and a bias current source, said third and fourth FETs and said bias current source series-connected in sequence between said supply voltage and said circuit common point, the drain and gate of said fourth FET connected to the gate of said second FET and the gates of said first and third FETs cross-coupled to the drains of said third and first FETs, respectively, said bias current source arranged to provide a starting current for said FET circuit, said first, second, third and fourth FETs being of a first polarity and the threshold voltages of said first and second FETs matched such that the transconductance Gm2 of said second FET is directly proportional to 1/R1.