TC285SPD-B0 Datasheet, PDF (6/30 Pages) Texas Instruments – 1004 x 1002 PIXEL IMPACTRONTM CCD IMAGE SENSOR

TC285SPD-B0
1004 x 1002 PIXEL IMPACTRON^TM CCD IMAGE SENSOR
SOCS093 – JANUARY 2006
Terminal functions
Terminal name No. I/O
Description
VDD
17
I Supply voltage for amplifiers
VCLD
IAG1
IAG2
ODB
19
I Supply voltage for Clearing drain & ESD circuits
6,23
I Image area gate-1
5,24
I Image area gate-2
4
I Supply voltage for anti-blooming drain
OUT
18
O Output signal, multiplier channel
SAG1
8,21
I Storage area gate-1
SAG2
SRG1
SRG2
CMG
7,22
I Storage area gate-2
10
I Serial register gate-1
11
I Serial register gate-2
12
I Charge multiplication gate
RST
13
I Reset gate
FP
VREFG
SUB
P+
20
16
3,9,14,15
1,2
I Field plate (See Figure 3)
I Amplifier reference gate
- Chip substrate
- Peltier cooler power supply -positive
P-
27,28
- Peltier cooler power supply -negative
Detailed description
The TC285SPD consists of five basic functional blocks: The image-sensing area, the
image–storage area, the serial register, the charge multiplier, and the charge detection
node with buffer amplifier. The location of each of these blocks is identified in the
functional block diagram.
Image-sensing and storage areas
Figure 1 and Figure 2 show the pixel cross-section with potential-well diagram and top
views of pixels in the image-sensing and storage areas. As light enters the silicon in the
image-sensing area, electrons are generated and collected in potential wells of the pixels.
Applying a suitable dc bias to the anti blooming drain provides blooming protection. The
electrons that exceed a specific 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 is 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. 28 columns at the left edge and 4
columns at the right 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. Additionally, 6 dark lines, located between the image
sensing area and the image-storage area, were added to the array for isolation.
6
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