difference v sg in other words under the condition that the reference current source i 1 is kept constant and the channel aspect ratio w 1 nl 1 of the pmos transistors q p11 u02dc q p1n is significantly lower than the channel aspect ratios w 1 l 1 of the pmos transistors q p2 u02dc q pn the voltage v sg across the pmos transistors q p11 u02dc q pn can be raised consequently avoiding the replicated currents i 2 u02dc i n being affected by the threshold voltage v t1 and being controlled within a desired range please refer to fig5 fig5 is a flowchart illustrating a method 500 of generating the current with immunity to the variation of the threshold voltage of the present invention the steps of the method are explained below step 502 provide a first mos transistor to be coupled to a voltage source step 503 provide a mos circuit to be coupled to the first mos transistor and the voltage source step 504 provide a feedback circuit to be coupled to the voltage source wherein the feedback circuit comprises a feedback end coupled between the mos circuit and the first mos transistor step 505 input a control voltage to the feedback circuit for control a current with a predetermined magnitude passing through the mos circuit as well as control a voltage of the feedback end in step 503 the mos transistor comprises a sixth mos transistor the channel aspect ratio of the sixth mos transistor can be adjusted to be lower than the channel aspect ratio of the first mos transistor or the threshold voltage of the sixth mos transistor can be adjusted to be higher than the threshold voltage of the first mos transistor in.