A resistorless current reference which has low temperature drift is designed for novel uncooled infrared focal plane array (IRFPA) readout circuits. First, the reference voltage VREF is obtained from a resistorless bandgap reference circuit. Then, the reference voltage is applied to the gate of a NMOS output transistor and is adjusted to force the NMOS output transistor to operate at zero TC (ZTC) point and generate a temperature independent reference current IREF eventually. The method is simulated in the CSMC 0.5μm CMOS process by using the Spectre software. The simulation result shows that the fluctuation of the output current is less than 4μA in the temperature range from 0℃ to 120℃. When a 3.3V power supply is used, the circuit just has its power dissipation of 0.94mW.