Bias Offset Correction Technique For Uncooled Infrared Bolometer Sensor Readout IC

Infrared bolometer sensor's variation is detected by voltage drop between a reference resistor and a bolometer resistor in this architecture. One of the serious problems in this architecture is that these resistors value has a process variation. So common-mode level could be different from expectation value in room temperature. Different common-mode level could lead to wrong output at the end of readout circuit. We suggest useful method to solve this problem. Difference correction using capacitor has reduced CM level difference to 88.5 % for I MΩ bolometer and reference resistor's 10 % variation.