TC253SPD-B0 Datasheet, PDF (5/23 Pages) Texas Instruments – 680 x 500 PIXEL IMPACTRON CCD IMAGE SENSOR

TC253SPDĆB0
680 × 500 PIXEL IMPACTRON CCD IMAGE SENSOR
Terminal Functions
TERMINAL
NAME
I/O
NO.
DESCRIPTION
ADB
15
I
Supply voltage for amplifiers and clearing drain
CMG
9
I
Charge multiplication gate
GND
3, 12, 20
Ground
IAG1
19
I
Image area gate 1
IAG2
5
I
Image area gate 2
NC
11, 14, 16
−
No connection
ODB
4
I
Supply voltage for antiblooming drain
P+
1, 2
I
Peltier cooler power supply—positive
P−
21, 22
I
Peltier cooler power supply—negative
SAG1
18
I
Storage area gate 1
SAG2
6
I
Storage area gate 2
SRG1
7
I
Serial register gate 1
SRG2
8
I
Serial register gate 2
SUB
10, 17
−
Chip substrate
VOUT
13
O
Output signal, multiplier channel
JULY 2003 − SOCS084
detailed description
The TC253SPD-B0 consists of four basic functional blocks: The image-sensing area, the image-storage area,
the serial register, and the charge multiplier. The location of each of these blocks is identified in the functional
block diagram.
image-sensing and storage areas
Figure 1 shows cross sections with potential-well diagrams. As light enters the silicon in the image-sensing
area, electrons are generated and collected in the potential wells of the pixels. Applying a suitable dc bias to
the antiblooming drain provides blooming protection. The electrons that exceed a specified level, determined
by the ODB bias, are drained away from the pixels. If it is necessary to remove all previously accumulated charge
from the wells, a short positive pulse must be applied to the drain. This marks the beginning of the new
integration period. After the integration cycle is completed, charge is quickly transferred into the memory where
it waits for readout. The lines can be read out from the memory in a sequential order to implement progressive
scan, or two lines can be summed together to implement the pseudo-interlace scan.
Twenty-four columns at the left edge of the image-sensing area are shielded from the incident light. These pixels
provide the dark reference used in subsequent video-processing circuits to restore the video-black level. Four
additional dark lines, located between the image sensing area and the image-storage area, are added for
isolation.
• POST OFFICE BOX 655303 DALLAS, TEXAS 75265
5