Various techniques are provided for implementing, operating, and manufacturing infrared imaging devices using integrated circuits. In one example, a system includes a focal plane array (FPA) integrated circuit comprising an array of infrared sensors adapted to image a scene, a plurality of active circuit components, a first metal layer disposed above and connected to the circuit components, a second metal layer disposed above the first metal layer and connected to the first metal layer, and a third metal layer disposed above the second metal layer and below the infrared sensors. The third metal layer is connected to the second metal layer and the infrared sensors. The first, second, and third metal layers are the only metal layers of the FPA between the infrared sensors and the circuit components. The first, second, and third metal layers are adapted to route signals between the circuit components and the infrared sensors.