Patent attributes
In one example, an apparatus comprises a photodiode, a charge storage unit, and a processing circuits configured to: transfer overflow charge from the photodiode to the charge storage unit to develop a first voltage; compare the first voltage against a first ramping threshold voltage to generate a first decision; generate, based on the first decision, a first digital value; transfer residual charge from the photodiode to the charge storage unit to develop a second voltage; compare the second voltage against a static threshold voltage to determine whether the photodiode saturates to generate a second decision; compare the second voltage against a second ramping threshold voltage to generate a third decision; generate, based on the third decision, a second digital value; and output, based on the second decision, one of the first digital value or the second digital value to represent an intensity of light received by the photodiode.