MCM20027 Motorola, MCM20027 Datasheet - Page 8

• Manufacturer Part Number: MCM20027
• Description: Color SXGA Digital Image Sensor 1280 x 1024 pixel progressive scan solid state image sensor with integrated CDS/PGA/ADC / digital programming / control
• Manufacturer: Motorola

MOTOROLA
MOTOROLA
SEMICONDUCTOR TECHNICAL DATA
The basic operation of the pixel relies on the photoelec-
tric effect where due to its physical properties silicon is
able to detect photons of light. The photons generate
electron-hole pairs in direct proportion to the intensity
and wavelength of the incident illumination. The appli-
cation of an appropriate bias allows the user to collect
the electrons and meter the charge in the form of a use-
ful parameter such as voltage.
The pixel architecture also requires all pixels in a row to
have common Reset , Transfer 1 and 2, Floating diffu-
How it works?
In brief, initially during Integration @T=0, both Transfer
Gates 1 and 2 and the Reset Gate is Open (On-Active
High). Transfer Gate 1 then Closes (Off) @ T=1, there-
by allowing Photodiode 1 to charge its well capacitance.
TRANSFER GATE 1
TRANSFER
ROW SELECT GATE
TRANSFER GATE 2
SHARED FLOATING
GATE 1
RESET
GATE
DIFFUSION GATE
RESET GATE
PHOTODIODE
ROW 1
T=0
Figure 2. Shared Floating Diffusion Pixel Architecture
T=1
T
row
T=2
TRANSFER
GATE 2
PHOTODIODE
ROW2
T
int
T
int
sion and Row Select gate controls. In addition all pixels
have common supply (V
tions. An optimized cell architecture provides enhance-
ments such as noise reduction, fill factor maximizations,
and antiblooming. The use of pinned photodiodes (2)
and proprietary transfer gate devices in the photoele-
ments enables enhanced sensitivity in the entire visual
spectral range and a lag free operation.
At this time Photodiode 2 is held at Reset level by hav-
ing Transfer Gate 2 and the Reset Gate open (On). Af-
ter 1 Row Period [T
(Off). This action causes Photodiode 2 to start charging.
When the integration (charging) of Photdiode 1 has
DIFFUSION
FLOATING
SHARED
GATE
T=3
T=4 T=5
T
row
Revision 8.0 - 28 November 2001 :
row
], @T=2 ,Transfer Gate 2 closes
DD
T=6
) and ground (V
ROW SELECT
ImageMOS
ImageMOS
GATE
SS
) connec-
MCM20027
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