Preliminary PI3033B datasheet

and the one with minimum Vpavg is assigned Vpavg(min). Then UCC =

{[Vpavg(max)-Vpavg(min)]/VGpavg}x100.

Output Circuit Of The Image Sensor

The video signal from each photo-site is connected to a common video line on the sensor. Each

photo-site is composed of a phototransistor with a series MOS switch connecting its emitter to a

common video line. The video line is connected to the pad labeled IOUT. The photo-sensing element

is the base of the phototransistor where it detects and converts the light energy to proportional charges

and stores them in its base capacitance. When the MOS switch is activated, the emitter is connected

to the video line and acts as source follower, producing an impulse current proportional to the stored

charges in the base. This current is a discrete-time analog signal output called the video pixel.

Accordingly the video pixel is proportional to the light energy impinging in the neighborhood of its

photo-sites. Figure 4, Video Pixel Output Structures, show the output structure of four photo-sites out

of 64. The multiplexing MOS switch in each photo-site terminates into the output pad, IOUT, through a

common video line. The shift register sequentially accesses each photo-site by a activating the MOS

switch. As they are accessed, a sequence of video pixels is sent to the IOUT where they are

processed with an external signal conversion circuit.

Figure 4. Video Pixel Output Structures

Page 6 of 13 Date: 03/18/05