Patent ID: 6552580
Filing Date: 2003-04-22
Classification: G05F

Abstract:
A multistage analog circuit for independently controlling a bias current in each stage of the multistage analog circuit having an input stage, an intermediate stage, and an output stage, comprising:a first independent current source connected to the input stage which controls the input stage of the circuit, an input signal of the input stage comprising a signal from the first independent current source; a second independent current source connected to the intermediate stage which controls the intermediate stage of the circuit, an input signal of the intermediate stage comprising a signal from the second independent current source; a third independent current source connected to the output stage which controls the output stage of the circuit, an input signal of the output stage comprising a signal from the third independent current source; an input of the multistage analog circuit connected to the input signal of the input stage, an output signal of the input stage connected to the input signal of the intermediate stage, and an output signal of the intermediate stage connected to the input signal of the output stage; and an output of the multistage analog circuit is an output signal of the output stage, and the output signal of the output stage remains at a constant voltage when the first current source is changed to affect an input transconductance of the circuit; wherein the bias current in each stage of the multistage analog circuit is set by the first, second, and third current sources, the output signal of the output stage remains at a constant voltage when the first current source is changed to affect an input transconductance of the circuit.