This paper presents a new approach for compensating resistance nonuniformity of uncooled microbolometers by
adjusting the bias currents of both detector and reference pixels. Contrary to conventional nonuniformity compensation
circuits, this approach eliminates the need for digital-to-analog converters (DACs), which usually occupy a large area,
dissipate high power, and require complicated external circuitry with high frequency data transfer to the microbolometer
chip. The proposed circuit uses a feedback structure that dynamically changes the bias currents of the reference and
detector pixels and does not need complicated external circuitry. A special feature of the circuit is that it provides
continuous compensation for the detector and reference resistances due to temperature changes over time. The circuit is
implemented in a 0.6μm 5V CMOS process and occupies an area of only 160μm × 630μm. Test results of the prototype
circuit show that the circuit reduces the offset current due to resistance nonuniformity about 2.35% of its
uncompensated value, i.e., an improvement of about 42.5 times is achieved, independent of the nonuniformity amount.
The circuit achieves this compensation in 12μsec. Considering its simplicity and low cost, this approach is suitable for
large array commercial infrared imaging systems.