Active pixel image sensors

An imaging device comprising:

• a first semiconductor chip comprising an active pixel sensor, a digital input/output, and a plurality of control circuits, wherein transistors of the active pixel sensor are all n-type or p-type transistors, and wherein at least one of the controls circuits operates under control of a timing signal externally input to the digital input/output;
• a second semiconductor chip comprising a timing generator which supplies the timing signal to the digital input/output of the first semiconductor chip;
• and
• a digital interface operatively connected between the digital input/output of first semiconductor chip and the second semiconductor chip.

An image sensor device comprising:

• a first semiconductor chip which includes image sensing circuitry, wherein the image sensing circuit includes an active sensor array and an analog-to-digital converter, and wherein transistors of the active sensor array and the analog-to-digital converter are all of a same conductivity type;
• a second semiconductor chip which includes image signal processing circuitry;
• and
• a digital interface which electrically connects the first semiconductor chip to the second semiconductor chip.