A pixel readout circuit with time-sharing background suppression has been introduced for 2D infrared focal plane array in this paper.In the design of subtracted current circuit,the self-cascode transistors are designed in long channel and works in their strong inversion mode,making the subtracted current insensitive to variations in process.This can effectively reduce the background suppression non-uniformity (BSNU) of pixel-to-pixel readout circuits.With 100 nA background current,3.28 μA subtracted current,2.7 ms integration time,and 10 mV threshold voltage mismatch of self-cascode transistors,the BSNU can be as low as 3.310%.