Abstract: Some embodiments include apparatus and methods having an amplifier, a capacitor network coupled to the amplifier, and switching circuitry coupled to the amplifier and the capacitor network. The switching circuit is configured to successively apply a selected reference voltage selected from among a first reference voltage, a second reference voltage, and a third reference voltage to the capacitor network in response to a digital input code to generate an output voltage. Additional embodiments are disclosed.

Abstract: An image sensing device comprising active pixels is disclosed, each pixel having a charge accumulation region for collecting charges generated by a photosensitive element such as a photodiode. A linear voltage to current converter, current mirrors, and a differential amplifier generate an output signal and minimize fixed pattern noise and improve the signal to noise ratio. Image quality is improved by reducing pixel blooming and image smearing through an improved method for resetting the pixels with a bias voltage reference which is less than Vdd. Active circuitry and physical device layout reduce the effects of IR voltage drops along the bus lines in a massive pixel array.