Patent ID: 6545540
Filing Date: 2003-04-08
Classification: H03F,H03H

Abstract:
A current mirror circuit comprising:an input port adapted to receive an input current; an output port adapted to provide an output current; a current mirror input transistor having an input electrode coupled through a resistor to a voltage supply terminal, a control electrode coupled to receive a reference voltage, and an output electrode coupled to said input port; a current mirror output transistor having an input electrode coupled through a resistor to said voltage supply terminal, an output electrode coupled to said output port, and a control electrode; and a resistor-capacitor low pass filter circuit installed in a control electrode-coupling path between said current mirror input and output transistors, and comprising a resistor coupled in series between the control electrode of said current mirror input transistor and the control electrode of said current mirror output transistor, and a capacitor directly connected between the control electrode of said current mirror output transistor and said voltage supply terminal, said resistor-capacitor low pass filter circuit being operative to make said output current at said output port equal to the frequency content of said input current as long as the frequency content of said input current is below the cut-off frequency defined by the time constant of said resistor-capacitor low pass filter circuit.