Method for improved dynamic range of BCMD image sensors

摘要

The dynamic range of an image array photosite is improved by, first, turning on a column clamp transistor having a source coupled to a photosite transistor source and a drain coupled to a photosite transistor drain, wherein the column clamp transistor is turned on by a column clamp transistor gate voltage; then decreasing a current supplied to a column sense line below a quiescent value, wherein the column sense line is coupled to the photosite transistor source; then turning on the photosite transistor by a photosite transistor gate voltage; then turning off the photosite transistor and the column clamp transistor at substantially the same time; then increasing the current above the quiescent value; and then returning the current to the quiescent value.