Built-in self-calibration of CMOS-compatible thermopile sensor with on-chip electrical stimulus
MEMS devices are expected to be used in a growing number of high-volume and low-cost applications. However because they usually require complex test stimuli rather than simple digital electronic signals as common VLSI systems to verify their specifications, testing and calibration costs have actually become a bottleneck to reduce the overall production cost of MEMS sensors. To address this issue, this paper presents an on-chip scheme to calibrate the responsivity of infrared thermopile temperature sensor with digital control signals. With the proposed method, the responsivity related to the ambient temperature can be calibrated before the target temperature being measured thus to achieve accurate temperature measurement. The proposed self-calibrating thermopile sensor design has been realized by CMOS-compatible process to prove the effectiveness of the self-calibration temperature measurement method.