Smart readout circuit including background suppression, non-uniformity compensation, and dead pixel correction

摘要

PURPOSE: A smart signal obtaining circuit for suppressing a background current, compensating ununiformity, and recovering bad pixels is provided to compensate the background current after storing the background current of an infrared sensing element to simultaneously suppress the background current and compensate the ununiformity by additionally incorporating an ADC/DAC and a memory for preventing the error caused by the junction leakage current. CONSTITUTION: In a smart signal obtaining circuit for suppressing a background current, compensating ununiformity, and recovering bad pixels, a gate of a first PMOSFET(Mskim) and a drain of a second PMOSFET(Mmem) are connected to a source of a third PMOSFET(Msel) to store a gate voltage of the first PMOSFET. The third PMOSFET has a gate of the third PMOSFET connected to Φmem, and a drain connected to an ADC/DAC via a BUSref. The ADC/DAC is connected to a memory(latch) by a BUSmem, so that a background current value stored to a current copier cell is digitalized and stored, and the gate voltage of the first PMOSFET is periodically reset.