The invention discloses a
high dynamic range reading circuit based on a backside illuminated
image sensor, which comprises an analog correlation sampling and
programmable gain amplifier, and is characterized in that a
voltage signal read from a pixel is amplified and then transmitted to a lower-level analog-to-
digital converter through a switch switching strategy of multiple times of sampling andholding and adjustment to a set
gain; the folding circulating analog-to-
digital converter is used for quantizing the signals subjected to preceding-stage preventive large sampling; the digital correlation sampling merging logic circuit is used for obtaining a real digital quantized
signal; the
time sequence control circuit is used for controlling the analog-to-digital
converters in each column line by line; an input
signal sequentially passes through the analog correlation sampling and
programmable gain amplifier, the folding circulation type analog-to-
digital converter and the digital correlation sampling merging logic circuit and then outputs a quantized signal, and a
clock signal passes through the
sequential control circuit and then is input into the folding circulation type analog-to-digital converter and the digital correlation sampling merging logic circuit. Quantization errors are reduced, the
dynamic range is enlarged, and the overall
power consumption and area of the readingcircuit are reduced.