Readout circuit with nonuniformity correction for the uncooled microbolometer

1 Introduction 1 With progress of technologies, uncooled microbolometer (UMB) is a viable alternative to many cooled IRFPAs (Infrared Focal Plane Arrays) because of its low manufacture cost, low power consumption, light weight and acceptable performance. One of the major problems in the readout circuit design of the microbolometer is the wide dynamic range of the interface circuit caused by serious nonuniformity. The nonuniformity, also referred as spatial noise, is a result of fabricatio…

Readout circuit with nonuniformity correction for the uncooled microbolometer

The output of uncooled microbolometer is nonuniform, and the traditional two-point nonuniformity correction method requires a tight restriction on substrate temperature. The circuit proposed by this article can relax the restriction on the substrate temperature and perform nonuniformity correction when reading out the image signal. The dummy pixels reduce static current. And the Column shared DACs transfer correction data to the gates of MOS transistors and the positive reference edge of amplifier, to control the bias current of detector and dummy one, and set the start point of integration. This circuit has higher sensitivity, wider dynamic range, and frame frequency of more than 30 Hz for 128×128 array. PSPICE simulation results seem that this circuit functions well.