Drive circuit (100, 200, 300, 400) for LED thermal emitters in pixel elements of an infrared scene projector (IRSP). At least two current sources (Q1, Q2, Q5) provide output currents (I1, I2, I3) which may be summed and provided to a single LED (150), or provided independently to two or more LEDs (450A, 450B). The current sources may have different gains (G1, G2, G3), and different turn-on voltages (Voffset). This allows for different resolutions for different ranges of apparent temperatures, such as high resolution in a low range and low resolution in a high range, thereby facilitating a digital implementation of the drive circuit(s).