Product specification2000 January 7
File under Image Sensors
Philips
Semiconductors
TRAD
Philips SemiconductorsProduct specification
Frame Transfer CCD Image SensorFT 18
•2/3-inch optical format
•1M active pixels (1024H x 1024V)
•Progressive scan
•Excellent anti-blooming
•V ariable electr onic shuttering
•Square pixel structure
•Hor . and Vert. binning
•100% optical fill factor
•High dynamic range (>60dB)
•High sensitivity
•Low dark current and fixed pattern noise
•Low read-out noise
•Data rate up to 40 MHz
•Frame rate up to 30 Hz
•Mirrored read-out option
Device structure
Optical size:7.68 mm (H) x 7.68 mm (V)
Chip size:8.9 mm (H) x 17.0 mm (V)
Pixel size:7.5 µm x 7.5 µm
Active pixels:1024 (H) x 1024 (V)
Total no. of pixels:1072 (H) x 1048 (V)
Optical black pixels:Left: 20Right: 20
Timing pixels:Left: 4Right: 4
Dummy register cells:Left: 7Right: 7
Contour lines:Bottom: 1Top: 4
Optical black lines:Bottom: 11Top: 8
Description
The FT 18 is a monochrome progressive-scan frame-transf er image
sensor offering 1K x 1K pixels at 30 frames per second through a
single output buffer . The combination of high speed and a high linear
dynamic range (>10 true bits at room temperature without cooling)
makes this device the perf ect solution f or high-end real time medical
X-ray, scientific and industrial applications. A second output can be
used for mirrored images. The device structure is shown in figure 1.
8 black lines
4 contour lines
8 black lines
Image
1024 active pixels
20
4
pix
Section
1 contour line
11 black lines
1024
active
lines
20
pix
2096
lines
Figure 1 - Device structure
2000 January2
Output
amplifier
Storage
Section
7
1072 cells
Output register
7
Philips SemiconductorsProduct specification
Frame Transfer CCD Image SensorFT 18
Architecture of the FT 18
The FT18 consists of a shielded storage section and an open image
section. Both sections have the same structure with identical cells
and properties. The only difference between the two sections is the
optical light shield.
The storage section is controlled by four storage clocks (B1 to B4).
An output register is located below the storage section for read-out.
The output register has buffers at both ends . This allo ws either normal
or mirrored read-out.
The optical centres of all pixels in the image section form a square
grid. The charge is generated and integrated in this section. The
image section is controlled by four image clocks (A1 to A4). After
integration, the image charge is completely shifted to the storage
section. The integration time is electronically controlled by charge
reset (CR).
IMAGE SECTION
Image diagonal
Aspect ratio
Active image width x height
Total width x height
Pixel width x height
Geometric fill factor
Image clock pins
Capacity of each clock phase
Number of active lines
Number of contour lines
Number of black lines
Total number of lines
Number of active pixels per line
Number of overscan (timing) pixels per line
Number of black reference pixels per line
Total number of pixels per line
Transport of the pixels in the output register is controlled by three
register clock phases (C1 to C3). The register can be used for v ertical
binning. Horizontal binning can be achieved by summing pixel
charges under the floating diffusion. More information can be found
in the application note. Figure 2 shows the detailed internal structure.
2
2
2
STORAGE SECTION
Storage width x height
Cell width x height
Storage clock phases
Capacity of each B phase
Number of cells per line x number of lines
8.040 x 7.860 mm
7.5 x 7.5 µm
2
B1, B2, B3, B4
<4.1nF per pin
1072 x 1048
OUTPUT REGISTER
Output buffers (three-stage source foll ower)
Number of registers
Number of register cells below storage
Number of extra cells to output
Output register horizontal transport clock pins
Capacity of each C-clock phase
Overlap capacity between neighbouring C-clocks
Reset Gate clock phases
Capacity of each RG
2
1 (bidirectional below storage)
1072
2 x 7
3 (C1..C3)
<85pF per pin
<35pF
2 pins (RGL, RGR)
<15pF
2000 January3
2
Philips SemiconductorsProduct specification
Frame Transfer CCD Image SensorFT 18
A2
A3
A4
A1
A2
A3
A4
A1
A2
One Pixel
OUTL
C3C3C3C3C3C3C3C3C3C3C3C3
OGC1
C3
A3
A4
A1
A2
A3
A4
A1
A2
A3
A4
A1
A2
A3
A4
A1
B2
B3
B4
B1
B2
A1
B3
B4
B1
B2
B3
B4
B1
B2
A1
B3
B4
B1
B2
B3
B4
B3
B2
A1
B3
B4
B1
column
7 extra cells
20 black & 4 timing columns
12 lines
1K active
IMAGE
images
lines
12 lines
FT CCD
STORAGE
1048 storage lines
C1C1C2C2C2 C1C2 C1C2C1
1
C2 C1C2 C1C2C2C1C1C2 C1C2C1C2
column
24+1
1K image pixels
column
24+1K
4 timing & 20 black columns
A2
A3
A4
A1
A2
A3
A4
A1
A2
A3
A4
A1
A2
A3
A4
A1
A2
A3
A4
A1
A2
A3
A4
A1
B2
B3
B4
B1
B2
A1
B3
B4
B1
B2
B3
B4
B1
B2
A1
B3
B4
B1
B2
B3
B4
B3
B2
A1A1
B3
B4
B1
column
24+1K+24
7 extra cells
OUTR
OG
C1
A1, A2, A3, A4: clocks of image section
B1, B2, B3, B4: clocks of storage section
C1, C2, C3: clocks of horizontal register
OG: output gate
Figure 2 - Detailed internal structure
2000 January4
Philips SemiconductorsProduct specification
Frame Transfer CCD Image SensorFT 18
Specifications
Absolute Maximum RatingsMin.Max.Unit
GENERAL:
storage temperature
ambient temperature during operation
voltage between any two gates
DC current through any clock (absolute value)
OUT current (no short circuit protections)
VOLTAGES IN RELAT ION TO VNS:
VPS, SFS
SFD
RD
All other pins
VOLTAGES IN RELAT ION TO VPS:
VNS
SFD, RD
SFS
All other pins
-55
-40
-20
-0.2
0
-30
-8
-15
-32
-0.5
+0
-8
-20
+80
+60
+20
+0.2
6
+0.5
+8
+0.5
+0.5
+30
+30
+8
+20
°C
°C
V
µA
mA
V
V
V
V
V
V
V
V
1
VNS
VPS
SFD
SFS
VCS
OG
RD
2
N substrate
P substrate
Source Follower Drain
Source Follower Source
Current Source
Output Gate
Reset Drain
One charge pumping cycle of the image gates (during line blanking), shifting the charge of one line back and forth
H
A1
L
H
A2
L
H
A3
L
H
A4
L
One cycle of the storage gates (during line blanking), moving one line from storage to output register
H
B2
L
H
B3
L
H
B4
L
H
B1
L
H
SSC
Start-Stop C-clocks
L
H
PB
Pre-Blanking
L
H
BLC
Black Level Clamp
L
H
CB
Composite Blanking
L
H
Charge Reset
CR
L
113199
1150
0
1964
28 37
46 55
3262
2644
3856
2050
0
C clocks stopped for 2 microseconds
0
0
1964
1.25 microseconds
36
750
72
1080 pixels until 1152
79
79
40
833
MHz
kHz
Pixel Timing
SSC
RG
Tp/6 = (1/36MHz)/6 = 4.63ns
dummy 1
. . . . . . .
dummy 7
black 1
H
L
H
C1
L
H
C2
L
H
C3
L
H
L
In this figure, charge is transported to the left output buffer (normal readout) by moving it from C1 to C2 to C3 etc.
By exchanging the timing of C1 and C2, charge will be transported to the right output buffer (mirrored readout).
Charge Pump (CP): a measure to reduce dark current due to interface states.
H
A1
L
H
A2
L
H
A3
L
H
A4
L
Hustle: moving the charge packets of one line from storage to the output register.
H
B1
L
H
B2
L
H
B3
L
H
B4
L
H
L
H
CR
L
H
L
H
PB
L
H
CB
L
For details see figure 3 "Line and pixel timing diagrams".
For details see figure 3 "Line and pixel timing diagrams".
Linetime: the C-clocks shift charge packets one-by-one to the selected output buffer.
............88
For details see figure 3 "Line and pixel timing diagrams".
CR before nominal integration
Black-Level Clamp (BLC): the video processing clamps the black lines to determine its output zero-level.
charge image (all lines) is moved from image to storage
by the image and storage clocks together (see Figure "Frame Shift Timing").
EEEEBBBLCBLCBBDDCC1video
By adding one CR-pulse during the horizontal blanking,
the effective integration time is decreased: "electronic shuttering"
2
Frame Shift Timing
Tp=1/(36MHz) = 27.8ns
H
A1
L
H
A2
L
H
A3
L
H
A4
L
H
B1
L
H
B2
L
H
B3
L
H
B4
L
48 Tp 750kHz
121048
121048
30Tp
18Tp
for all A and B clocks,
duty cycle = 5/8
1047
1047
Figure 4 - Frame timing diagrams
2000 January7
Philips SemiconductorsProduct specification
Frame Transfer CCD Image SensorFT 18
Performance
The performance of the FT 18 is described for modes of operation
with 25 frames/sec or 30 frames/sec respectively. Measurements
for the FT 18 are done under the f ollo wing circumstances (values in
brackets apply for the 30 frames/sec mode):
• VNS is adjusted as low as possible while maintaining proper
Ver tical Anti-Blooming.
• Integration takes place under 2 gates with 10V clock s wing during
40ms (33.33ms)
Linear / SaturationMin.TypicalMax.Unit
Overexposure over entire area while maintaining good VAB
Vertical resolution (MTF) @ 67 lp/mm
Quantum efficiency @ 450 nm
Quantum efficiency @ 520 nm
Quantum efficiency @ 600 nm
Quantum efficiency @ 800 nm (near IR)
Image lag
White Shading
Random Non-Uniformity (RNU)
Sensitivity @ 3200K without IR cut-off filter
Smear without shutter
5
Dynamic range
RMS read-out noise
• The vertical transport or frame shift frequency equals 750kHz
(714kHz).
• The horizontal transport or read-out frequency equals 36MHz
(40MHz).
• The RMS read-out noise of the output buffers and the FPN are
measured in the bandwidth 0.1-18MHz (0.1-20MHz).
• The performance in dark is given at a temperature of 318K / 45°C.
Note that the dark current decreases by a factor of two for every
decrease of temperature of approximately 10°C.
300
25
10
21
18
5
-
-
120
40
45
90
5.6
60
-
-
11
22
19
0
-
1.0
45
-
-
5.8
-
63.8
29
-
-
-
-
-
-
-
2.5
1.4
-
-
-
-
-
0.39
38
lux
%
%
%
%
%
%
%
%
kel.
kel.
kel.
kel.
kel/lux
%
dB
el
30 frames/sec mode only
Sensitivity @ 3200K without IR cut-off filter
Smear without shutter
5
Dynamic range
RMS read-out noise
1
White Shading is defined as the ratio of the one-σ value of an 8x8 pixel blurred image (low-pass) to the mean signal value.
2
Random Non Uniformity is defined as the ratio of the one-σ value of the highpass image to the mean signal value at nominal light.
3
Q
is determined from the lowpass filtered image.
max
4
Q
of the output register may be increased up to 200kel. In this case the charge packets of the pixels may get mixed in the output register
max
during horizontal transport. This may reduce the number of times that the output register needs to be read out if lines are read out solely to be
dumped.
5
The smear condition is: overexposure with a spot with a height of 10% of the image height (approx. 100 lines).
4.6
60
-
4.8
-
63.5
30
-
0.40
40
kel/lux
%
dB
el
2000 January8
Philips SemiconductorsProduct specification
Frame Transfer CCD Image SensorFT 18
30
20
10
Quantum efficiency (%)
0
400500600700800900
Wavelength (nm)
Figure 5 - Quantum efficiency versus wavelength
2000 January9
Philips SemiconductorsProduct specification
Frame Transfer CCD Image SensorFT 18
Output BuffersMin.TypicalMax.Unit
Conversion factor
Supply current
Bandwidth
Output impedance buffer (R
= 3.3kΩ, C
load
Dark ConditionMin.TypicalMax.Unit
Dark current
Black level offset
1
Dark condition at 25 frames/sec:
Average dark signal
Shot noise of the dark current
Horizontal shading
Vertical shading
Fixed Pattern Noise
2
in dark (FPN)
Dark condition at 30 frames/sec:
Average dark signal
Shot noise of the dark current
Horizontal shading
Vertical shading
Fixed Pattern Noise
2
in dark (FPN)
= 2pF)
load
8.510
4
110
400
-
-
-
-
-
-
-
-
-
-
-
-
-
-
56
-
-
-
-
47
-
-
-
-
11.5µV/el.
mA
MHz
Ω
240
25
67
10
25
66
19
56
10
25
56
19
pA/cm
el
el
el
el
el
el
el
el
el
el
el
2
1
Black level offset is defined as the difference in dark signal of a black refence line and an active image line.
2
FPN is the one-σ value of the highpass image.
2000 January10
Philips SemiconductorsProduct specification
Frame Transfer CCD Image SensorFT 18
Application information
Current handling
One of the purposes of VPS is to drain the holes that are generated
during exposure of the sensor to light. Free electrons are either
transported to the VRD connection and, if excessive (from overexposure), free electrons are drained to VNS. No current should
flow into any VPS connection of the sensor . During high ov erexposure
a total current 10 to 15mA through all VPS connections together
may be expected. The PNP emitter follower in the circuit diagram
(figure 6) serves these current requirements.
VNS drains superfluous electrons as a result of overexposure. In
other words, it only sinks current. During high overexposure a total
current of 10 to 15mA through all VNS connections together ma y be
expected. The NPN emitter follower in the circuit diagram meets
these current requirements.
Decoupling of DC voltages
All DC voltages should be decoupled with a 100nF decoupling
capacitor. This capacitor must be mounted as close as possible to
the sensor pin. Further noise reduction (by bandwidth limiting) is
achieved by the resistors in the connections between the sensor
and its voltage supplies. The electrons that build up the charge
packets that will reach the floating diffusions only add up to a small
current, which will flow through VRD . Theref ore a large series resistor
in the VRD connection may be used.
Outputs
T o limit the on-chip po wer dissipation, the output buff ers are designed
with open source outputs. Outputs to be used should therefore be
loaded with a current source or more simply with a resistance to
GND. In order to prevent the output (which typically has an output
impedance of about 400Ω) from bandwidth limitation as a result of
capacitive loading, load the output with an emitter follo wer b uilt from
a high-frequency transistor. Mount the base of this transistor as close
as possible to the sensor and keep the connection between the
emitter and the next stage short. The CCD output buffer can easily
be destroyed by ESD. By using this emitter follower, this danger is
suppressed; do NOT reintroduce this danger by measuring directly
on the output pin of the sensor with an oscilloscope probe. Instead,
measure on the output of the emitter follower. Slew rate limitation is
prevented by avoiding a too-small quiescent current in the emitter
follower; about 10mA should do the job. The collector of the emitter
follower should be decoupled properly to suppress the Miller effect
from the base-collector capacitance.
A CCD output load resistor of 3.3kΩ typically results in a bandwidth
of 110MHz. The bandwidth can be enlarged to about 130MHz by
using a resistor of 2.2kΩ instead, which, however, also enlarges the
on-chip power dissipation.
Device protection
The output buffers of the FT 18 are likely to be damaged if VPS
rises above SFD or RD at any time. This danger is most realistic
during power-on or power-off of the camera. The RD voltage should
always be lower than the SFD voltage.
Never exceed the maximum output current. This may damage the
device permanently. The maximum output current should be limited
to 6mA.
Be especially aware that the output buffers of these image sensors
are very sensitive to ESD damage.
Because of the fact that our CCDs are built on an n-type substrate,
we are dealing with some parasitic npn transistors. To avoid activ ation
of these transistors during switch-on and switch-off of the camera,
we recommend the application diagram of figure 6.
2000 January11
Philips SemiconductorsProduct specification
Frame Transfer CCD Image SensorFT 18
Device Handling
An image sensor is a MOS device which can be destroy ed by electrostatic discharge (ESD). Therefore, the device should be handled
with care.
Always store the de vice with short-circuiting clamps or on conductive
foam. Alwa ys s witch off all electric signals when inserting or removing
the sensor into or from a camera (the ESD protection in the CCD
image sensor process is less effective than the ESD protection of
standard CMOS circuits).
Being a high quality optical device, it is important that the cover
glass remain undamaged. When handling the sensor , use fingercots.
VSFD
BC
850C
0.5-1mA
27
Ω
BAT74
Schottky!
Ω
15
BAT74
Schottky!
10k
Ω
BAT74
BC
850C
0.5-1mA
0.5-1mA
BC
860C
100nF
100nF
100nF
100nF
When cleaning the glass we recommend using ethanol (or possibly
water). Use of other liquids is strongly discouraged:
• if the cleaning liquid evaporates too quickly, rubbing is likely to
cause ESD damage.
• the cover glass and its coating can be damaged by other liquids.
Rub the window carefully and slowly.
Dry rubbing of the window may cause electro-static charges or
scratches which can destroy the device.
keep short
VNS
SFD
VPS
VRD
<10mm!keep short!
10k
Ω
Ω
BFR
92A
output for
preprocessing
10mA
OUT
VCS
VOG
100 Ω
3.3k
Ω
100nF
10k
100nF
100nF
1k
Ω
<7pF!
Figure 6 - Application diagram to protect the FT 18
2000 January12
Philips SemiconductorsProduct specification
Frame Transfer CCD Image SensorFT 18
Pin configuration
The FT18 is mounted in a ceramic DIL 32-pin package.
The position of pin 1 is marked with a white dot on top of the package.
N substrate
N substrate
P well
P well
Source Follower Drain Left
Source Follower Drain Right
Source Follower Source Left
Source Follower Source Right
Current Source Gate Left
Current Source Gate Right
Output Gate left
Output Gate Right
Reset Drain Left
Reset Drain Right
Image Clock (Phase 1)
Image Clock (Phase 2)
Image Clock (Phase 3)
Image Clock (Phase 4)
Storage Clock (Phase 1)
Storage Clock (Phase 2)
Storage Clock (Phase 3)
Storage Clock (Phase 4)
Register Clock (Phase 1)
Register Clock (Phase 1)
Register Clock (Phase 2)
Register Clock (Phase 2)
Register Clock (Phase 3)
Register Clock (Phase 3)
Reset Gate Left
Reset Gate Right
Output Left
Output Right