An image processing system includes a charge-coupled device sensor having a wide input dynamic range, and an analog front end circuit coupled to the charge-coupled device sensor. The front end circuit includes an analog-to-digital converter module to receive an input analog signal from the charge-coupled device sensor, the analog-to-digital converter module having a signal to noise ratio corresponding to a predetermined number of bits and a higher resolution than the predetermined number of bits. The front end circuit further includes a digital multiplier module coupled to the analog-to-digital converter module, the analog-to-digital converter module and the digital multiplier module to adjust a full scale input range at the analog-to-digital converter module over the wide range without loss in analog-to-digital conversion resolution.

One embodiment of the present invention includes a pipelined analog-to-digital converter (ADC) comprising a plurality of pipeline stages. At least one of the plurality of pipeline stages comprises a feedback transistor-follower combination interconnected between a positive source voltage and a summation node and configured to set a voltage of the summation node approximately equal to a sample-and-hold voltage associated with a preceding one of the plurality of pipeline stages. The at least one of the plurality of pipeline stages also comprises a current mirror coupled to the feedback transistor-follower combination configured to provide a first current that is approximately equal to a second current that is associated with the feedback transistor-follower combination. The at least one of the plurality of pipeline stages further comprises an output resistor configured to set an output voltage of the respective at least one of the plurality of pipeline stages based on the first current.

Converter systems are provided which complement sample capacitors in at least one converter stage with replica capacitors. The replica capacitors are switched to receive replica charges from the analog input signal during the same operational mode in which the sample capacitors receive undesirable remnant charges. In an initial portion of a subsequent operational mode, the remnant capacitors are briefly switched to the sample capacitors to substantially cancel the remnant charges. The sample capacitors then participate in obtaining input-signal samples during the remainder of the subsequent operational mode. Because the remnant charges have been substantially canceled, the accuracy of the subsequent operational mode is considerably enhanced. In another system embodiment, the replica capacitor is replaced by a discharge switch which provides a discharge path in an initial portion of the subsequent operational mode.

Methods and systems for input voltage droop compensation in video/graphics front-end systems. The method of an embodiment of the invention captures input voltage information supplied to an Analog-to-Digital Converter (ADC) operatively coupled to a bypass capacitor in a video/graphics front-end system; calculates a droop in the input voltage in ADC due to a charge sharing between an input sampling capacitor of the ADC and the bypass capacitor; and compensates for the value of the bypass capacitor using an output of the ADC. Embodiments of the invention provide an improved freedom in the choice of off-chip bypass capacitance in video/graphics front-end systems.