A complementary metal oxide semiconductor (CMOS) readout integrated circuit (ROIC) for an uncooled focal plane array (UFPA) is presented. The circuit consists of four major parts: a bolometer current direct injection (BCDI) input circuit, a column-shared capacitor feedback transimpedance amplifier (CTIA) integration circuit, a column-shared correlated double sampling (CDS) circuit, and a common output circuit. By applying the BCDI input circuit and the column-shared integration circuit of CTIA structure, high performance (high gain, a highly st...