There are two versions of the IS32 OpticRAM: the IS32 and IS32A. Beginning in September 1983, the IS32 was replaced in favor of the IIS32A. The only difference between the two devices is size. The IS32A is exactly 20 percent smaller in the horizontal and vertical dimensions. The dimensions below are for the IS32A.

To calculate dimensions for the larger IS32 device, multiply by 1.25.

• 1. ARRAY: 128 x 256 electrical addressable elements per array (4420 microns x 876.8 microns). The physical organization of the array is actually a 514 x 129 grid with staggered cell placement as indicated in figure D- 1.
• 2. ROW: 877 microns.
• 3. COLUMN: 4420 microns.
• 4. ELEMENT SIZE: 6.4 microns vertical by 6.4 microns horizontal.
• 5. VERTICAL PITCH (Row Pitch): 6.8 microns.
• 6. HORIZONTAL PITCH (Column Pitch): 8.6 microns.
• 7. SPACING between left and right array: 120 microns.
• 8. DISTANCE from surface of OpticRAM chip to top of the glass = 940 microns (plus or minus 100 microns).

Broadband sensitivity of the IS32 OpticRAM is approximately 2uJ/sa cm.

Silicon detectors have a useful optical sensitivity over the region of the spectrum is which silicon absorbs photons. This extends from 200 nanometers to 1100 nanometers. However, a complete characterization of the IS32 is still under way. The sensitivity follows the silicon characteristic curve since the IS32 is built using silicon. The IS32 is impervious to damage by high light intensity. It has a high quantum efficiency and a binary output that is proportional to the amount of incident light and integration time (referenced to a threshold). However, oversaturation of the IS32 by more than 4 F-stops will, for the duration of oversaturation, make the first half of the array all light and the other half all dark. This is only a temporary situation for the duration of the saturation. The IS32 is sensitive up to near UV.

The IS32 chip is mounted in the package with 20 mils tolerance in both the X and Y axis. This suggests that if an OpticRAM package is replaced in a camera, a physical realignment of the camera to the scene is necessary. The tolerance from surface of the array to the lens mount from camera to camera is 20 mils with a 6 degree rotational tolerance.