AMI AMIS

AMIS-720658: Contact Image Sensor
Data Sheet
1.0 General Description
AMI Semiconductor’s AMIS-720658 (PI6058) contact image sensor (CIS) is a selectable 600 or 300 dot per inch (dpi) resolution linear
image sensor, which employs AMI Semiconductor’s proprietary CMOS image sensing technology. The sensor contains an on-chip
output amplifier, power down circuitry and parallel transfer features that are uniquely combined with the present-day active-pixel-sensor
technology. The image sensors are designed to be cascaded end-to-end on a printed circuit board (PCB) and packaged in an image
sensing module. Applications for the sensor array include facsimiles, PC scanners, check readers, and office automation equipment.
Figure 1 is a block diagram of the sensor. Each sensor consists of 344 active pixels, their associated multiplexing switches, buffers and
an output amplifier circuit with a power down feature. The sensors pixel-pixel spacing is approximately 42.3µm. The size of each sensor
without the scribe lines is 14560µm by 335µm.
2.0 Key Features
•
•
•
•
•
•
•
•
•
•
•
•
600 and 300dpi selectable resolutions
344 or 172 image sensor elements (pixels)
42.3µm (600dpi) pixel center-to-center spacing
On-chip amplifier
Single 3.3V power supply
3.3V input clocks and control signals
4.0MHz maximum pixel rate
Parallel / integrate and transfer
Power-down circuit
High sensitivity
Low power
Low noise
14560µm
42.3µm
22.95µm
1
2
4
3
Row of 344 Pixels (600dpi)
and Video Line Multiplexer
342
343
344
Parallel Transfer, Storage Cells and Readout Registers
335µm
Scan Direction
Amplifier, PowerDown and Offset
Control
SI
GBST
CLK
SIC
SR
VDD
VOUT
VSS
Figure 1: Sensor Block Diagram
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VREF
SO
AMIS-720658: Contact Image Sensor
Data Sheet
3.0 Unique Features
There are six unique features incorporated into the AMIS-720658 which improve the sensor’s performance.
3.1 Pixel-to-pixel Offset Cancellation Circuit
The sensor employs a pixel-to-pixel offset cancellation circuit, which reduces the fixed pattern noise (FPN), and amplifier offsets. In
addition, this innovative circuit design greatly improves the optical linearity and low noise sensitivity.
3.2 Parallel Integrate, Transfer and Hold
The sensor has a parallel integrate, transfer and hold feature, which allows the sensor to be read out while photon integration is taking
place. These features are approached through the use of an integrate-and-hold cell, located at each pixel site. Each pixel’s charge is
read from its storage site as the sensor’s shift register sequentially transfers each pixel’s charge onto a common video line.
3.3 Dual Scan Initiation Inputs, GBST and SI
Each sensor has two scan initiation inputs, the global start pulse (GBST) and the start pulse (SI), which are compatible with standard
3.3V CMOS clocks. These clocks help to reduce the sensor-to-sensor transition FPN by initializing and preprocessing all sensors
simultaneously before they start their readout scan. The internal shift register starts the scan after GBST is clocked in on the falling
edge of the clock input (CLK).
During the first 82 clock cycles following a GBST pulse, all the pixels of all the cascaded sensors cycle through their pre-scan
initialization process that reduces FPN and reset noise.
A sequence of cascaded sensors has a unique first sensor and identically behaving subsequent sensors. The start input control (SIC)
defines whether a sensor will be the first sensor that self-starts the readout of its pixels or will be a subsequent sensor that waits for the
SI before starting the readout of its pixels. With its SIC tied high (Vdd), the first sensor self-starts the readout of its pixels after 82 clock
cycles of delay. With their SIC tied low (Ground), all of the subsequent sensors delay their readout of their pixels until after they receive
a SI pulse. Furthermore, the first sensor’s SI is left unconnected, while the subsequent sensors all have their SI connected to the endof-scan (SO) of their respective preceding sensor. Just prior to finishing its readout of its pixels, each sensor will send a SO pulse to its
respective subsequent sensor so that its respective subsequent sensor will continue the readout of pixels without a pause or gap in
readout. The external module-level start pulse (SP) is connected to all of the sensors' GBST inputs.
th
For example in the 600dpi mode, when the first sensor completes its scan, its SO appears on the rising edge of 416 clock cycle after
th
the entry of GBST and the rising edge of the 11 last pixel, in order to have a continuous pixel readout between sensors in a module.
This SO enters as the SI clock of the second and subsequent sensors; hence all subsequent sensors will start their register scan after
each of the preceding sensors completes its scan.
3.4 Power Saving
Each sensor incorporates a power-saving feature when multiple sensors are cascaded together to form a linear imaging array. When a
particular sensor is selected to be read out, the SIC on each sensor selects a unique feature of powering up that sensor’s output
amplifier and powering it down when not selected.
3.5 Common Reference Voltage Between Cascaded Sensors
Each sensor has an input bias control (VREF), which serves as an offset voltage reference. Each bias control pad is tied to its own
amplifier’s reference bias input. In operation, these pads on every sensor are connected together. Each sensor then “shares” the same
bias level to maintain a constant bias among all of the sensors.
3.6 Selectable Resolutions of 600dpi and 300dpi
The select resolution input (SR) is connected to high (Vdd) or to low (Ground) to set the sensor to operate in the 600dpi or 300dpi
mode, respectively. In the 600dpi mode, all 344 pixels are clocked out, whereas in the 300dpi mode, Pixels 1 and 2 are combined, 3
and 4 are combined and so on up to Pixels 343 and 344 being combined. One half of the pixel amplifiers and one half of the scanning
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AMIS-720658: Contact Image Sensor
Data Sheet
register are then disabled. As a result, sensitivity in the 300dpi mode will be twice that of the 600dpi mode. The 300dpi readout time will
be approximately half of the 600dpi readout time. Unlike a CCD array, both the 300dpi and 600dpi arrays can operate with the same
clock frequency.
4.0 Functional Description
4.1 Input / Output Terminals
The AMIS-720658 image sensor has ten bond pads that become inter-connected when they are cascaded end-to-end on a PCB and
packaged in an image sensing module. Their symbols and functions are listed in Table 1.
Table 1: Input and Output Terminals
Signal
I/O
Description
Start pulse:
SI
I
Input to start a line scan (see discussion of the sensors unique features for further details)
Global start pulse:
GBST
I
Globally initializes the start inputs of all sensors and starts the scanning process of the first sensor (see
discussion of the sensors unique features for further details)
Clock:
CLK
I
Clock input for the shift register
Start input control:
SIC
I
Input to control the start pulse to the first sensor (see discussion of the sensors unique features for further
details)
Select resolution:
SR
I
Selects the 600 or 300dpi mode (see discussion of the sensors unique features for further details)
VDD
I
Power supply
Video output voltage:
VOUT
O
Output video signal from the chip
VSS
I
Ground
Reference voltage:
VREF
I
Externally applied reference input voltage for the amplifier output; sets the output’s reset (dark) level
End-of-scan pulse:
SO
O
Output from the shift register at the end of a scan
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AMIS-720658: Contact Image Sensor
Data Sheet
4.2 Bonding Pad Layout Diagram
Figure 2 shows the bonding pad locations for the AMIS-720658 sensor.
14560µm
2290µm
2370µm
335µm
SI
GBST
CLK
SIC
SR
VDD
VSS
VOUT
VREF
Pad Location Table
Pad
Location
SI
Start Pulse
GBST
CLK
SIC
SR
VDD
VOUT
Global Start Pulse
Clock
Start Input Control
Select Resolution
Power Supply
Y
30.0
30.0
30.0
30.0
2290.0
2637.0
3649.0
3929.0
4243.0
4850.0
5135.0
9498.0
9844.0
12190.0
VSS
VREF
Video Output Voltage
Ground
Reference Voltage
30.0
34.0
30.0
34.0
30.0
SO
End of Scan Pulse
30.0
Notes:
1. Definition of X and Y Pad Locations
X
SI
Y
X
X
2. Each pad is 80um x 70um
3. All dimensions are in um
4. Die size does not include the scribe line
Figure 2: AMIS-720658 Bonding Pad Layout
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GBST
4
SO
AMIS-720658: Contact Image Sensor
Data Sheet
4.3 Wafer Scribe Line
Figure 3 outlines the scribe line dimensions surrounding the sensor die on a wafer.
55µm
335µm
55µm
14560µm
55µm
Figure 3: Wafer Scribe Line
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55µm
AMIS-720658: Contact Image Sensor
Data Sheet
5.0 Device Specifications
Table 2 lists the device specifications of the AMIS-720658 sensor operating under the typical values of the recommended operating
°
conditions in table 3; pixel rate of 3.0MHz, temperature of 25 C, Vdd = 3.3V, VREF = 1.2V, integration time of 1.0ms for 300dpi and
2.0ms for 600dpi, no resistive load on Vout and with a capacitive load of 50pf on Vout to ground. The average output voltage Vpavg,
which is defined as the voltage difference between the average pixel level in the light and the average pixel level in the dark, will be
adjusted to approximately 0.7V, unless stated otherwise. A linear array of uniform green LED’s will be used as the light source for
measurements requiring illumination, unless otherwise stated.
Table 2: Device Specifications
Parameter
(1)
Number of pixels
@ 600dpi
@ 300dpi
(1)
Pixel-to-pixel spacing
@ 600dpi
@ 300dpi
Pixel vertical height
(2)
Dark output voltage level
(3)
Dark output non-uniformity
(4)
Photo-response non-uniformity
(5)
Adjacent photo-response non-uniformity
Sensor-to-sensor photo-response
(6)
Non-uniformity
(7)
Saturation voltage
(8)
Sensitivity
@ 600dpi
@ 300dpi
(9)
Photo response linearity
(10)
Individual pixel noise (rms)
@ 600dpi
Image lag (chip average)
Power supply current
Wafer thickness
Symbol
Min.
Typ.
344
172
344
172
42.3
84.6
25
42.3
84.6
25
Vd
Ud
Up
Upn
PRL
P_noise
100
±15
±15
±10
%
0.95
Sv
V
2
750
1500
−2.5
3.0
IDD per chip
325
Units
µm
µm
µm
V
mV
%
%
1.2
Usensor
VSat
Max.
60
350
+2.5
10
2
80
375
V / uJ / cm
2
V / uJ / cm
%
mV
%
mA
µm
Notes
1.
The SR input is connected to high (Vdd) or to low (ground) to set the sensor to operate in the 600dpi or 300dpi mode, respectively. In the 600dpi mode, all 344 pixels are
clocked out, whereas in the 300dpi mode, Pixels 1 and 2 are combined, 3 and 4 are combined and so on up to Pixels 343 and 344 being combined. One half of the pixel
amplifiers and one half of the scanning register are then disabled. As a result, sensitivity in the 300dpi mode will be twice that of the 600dpi mode. The 300dpi readout
time will be approximately half of the 600dpi readout time.
2.
Dark output voltage (Vd). Vd is the average dark output level and is essentially the offset level of the video output in the dark. The dark level is set by the voltage on
VREF and which must be applied externally, to a voltage of 1.2V for optimal module operation.
3.
Dark output non-uniformity (Ud). Ud = Vdmax – Vdmin, where Vdmax is the maximum pixel output voltage in the dark and Vdmin is the minimum pixel output voltage in
the dark.
4.
Photo-response non-uniformity (Up). Up = ((Vpmax-Vpavg)/Vpavg) x 100% or ((Vpavg-Vpmin)/Vpavg) x 100%, whichever is the greater, where Vpmax is the maximum
pixel output voltage in the light, Vpmin is the minimum pixel output voltage in the light and Vpavg is the average output voltage of all pixels in the light.
5.
Adjacent photo-response non-uniformity (Upn). Upn = [Max(Vpn, Vpn+1) - Min(Vpn, Vpn+1)) / Min(Vpn, Vpn+1)) x 100%, where Vpn is the pixel output voltage of pixel n
in the light and Vpn+1 is the pixel output voltage of pixel n+1.
6.
Sensor-to-sensor photo-response non-uniformity (Usensor). Usensor = (Vpavg – Wavg) / Wavg, where Wavg is the average output of all sensors on the same wafer that
pass all other specifications.
7.
Saturation voltage (Vsat) is defined as the maximum video output voltage swing measured from the dark level to the saturation level. It is measured by using the module
LED light source with the module imaging a uniform white target. The LED light level is increased until the output voltage no longer increases with an increase in the
LED brightness. The dark level is set by the voltage on VREF and which must be applied externally, to a voltage of 1.2V for optimal module operation.
8.
Sensitivity (Sv) is defined as the slope of the Vpavg vs. Exposure curve.
9.
Photo-response linearity (PRL). PRL = ((Vratio – Tratio) / Tratio) x 100% where Vratio = (Vavg2 – Vavg1) / (Vavg3 – Vavg1), Tratio = (Tint2 – Tint1) / (Tint3 – Tint1),
Vavg1 is the average output voltage of all pixels under fixed illumination with an integration time of Tint1 selected so that Vavg1 is around 0.1 V, Vavg2 is the average
output voltage of all pixels under the same fixed illumination with an integration time of Tint2 selected so that Vavg2 is around 0.4 V, Vavg3 is the average output voltage
of all pixels under the same fixed illumination with an integration time of Tint3 selected so that Vavg3 is around 0.7 V.
10. Individual pixel noise in rms (P_noise). The individual pixel noise in rms is defined as the standard deviation of each pixel in the dark. This can also be though of as
output referred noise as it is measured at the sensor output.
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AMIS-720658: Contact Image Sensor
Data Sheet
6.0 Recommended Operating Conditions
Table 3 lists the recommended operating conditions at 25°C.
°
Table 3: Recommended Operating Conditions at 25 C
Parameter
Symbol
Min.
Power supply
Vdd
3.1
(1)
Clock input voltage high level
Vih
2.8
(1)
Clock input voltage low level
Vil
(2)
Reference voltage
VREF
1.1
Clock frequency
(3)
(4)
Pixel rate
(5)
Integration time (line scan rate)
First die
Subsequent die
(6)
Clock pulse duty cycle
Resistive load on Vout
Capacitive load on Vout
Tint
Typ.
3.3
Max.
3.5
1.2
0.5
1.3
Units
V
V
V
V
0.5
3.0
4.0
MHz
0.5
3.0
4.0
MHz
µs
µs / die
%
KΩ
pF
107
86
50
5
50
Notes:
1.
Applies to all clocks; GBST, SI and CLK.
2.
The dark level is set by the voltage on VREF and which must be applied externally, to a voltage of 1.2V for optimal module operation.
3.
Although the device will operate with a pixel rate of less than 500 kHz, it is recommended that the device be operated above 500 kHz to maintain performance
characteristics. Operating below 500 kHz may result in leakage current degradation.
4.
One pixel is clocked out for every clock cycle.
5.
Tint is the integration time of a single sensor and is the time between two start pulses. The minimum integration time is the time it takes to clock out 82 inactive pixels
and 344 active pixels for the 600dpi mode, or 82 inactive pixels and 172 active pixels for the 300dpi mode, at a given frequency.
However, if several sensors are cascaded together in a module then the minimum integration time for the 600dpi mode is the time it takes to clock out 82 inactive pixels
and 344 active pixels from the first sensor and 344 pixels from each of all subsequent sensors, at a given frequency.
Similarly, for cascaded sensors in the 300dpi mode, the minimum integration time is the time it take to clock out 82 inactive pixels and 172 active pixels from the first
sensor and 172 pixels from each of all subsequent sensors, at a given frequency.
6.
The clock duty cycle is defined as the ratio of the positive duration of the clock to its period.
7.0 Absolute Maximum Ratings
Table 4: Absolute Maximum Ratings
Parameter
Power supply voltage (Vdd)
Clock input voltage high level (Vih)
Clock input voltage low level (Vil)
(1)
(1)
Symbols
Vdd
Max.
8
Units
V
Vih
Vdd + 0.3
V
-0.3
V
Operating temperature
Vil
-10 to +50
°C
Operating humidity
+10 to +85
RH%
Storage temperature
Storage humidity
-25 to +75
+10 to +90
°C
RH%
Note:
1.
Applies to all clocks.
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AMIS-720658: Contact Image Sensor
Data Sheet
8.0 Timing Requirements
Table 5 lists the timing requirements for the 600 and 300dpi modes, and their associated timing diagrams are shown in Figures 4-10. All
measurements were taken at a pixel rate of 3 MHz, integration time of 2ms, Vout of 0.7V, no resistive load on Vout and with a
capacitive load of 50pf on Vout to ground.
Table 5: Timing Requirements
Parameter
Clock (CLK) period
Clock (CLK) pulse width
Clock (CLK) duty cycle
(1)
Data setup time
Data hold time
(1)
(2)
Clock (CLK) rise time
(2)
Clock (CLK) fall time
(2)
End-of-scan (SO) rise time
(2)
End-of-scan (SO) fall time
(3)
Global start (GBST) rise time
(3)
Global start (GBST) fall time
(4)
Pixel transition time
Symbol
CLKp
CLKpw
Min.
Tset
20
Thold
25
CLKrt
CLKft
SOrt
SOft
GBSTrt
GBSTft
ptt
Typ.
330
165
50
Max.
Units
ns
ns
%
ns
ns
35
30
50
50
35
30
155
ns
ns
ns
ns
ns
ns
ns
Notes:
1.
The shift register will load on all falling CLK edges, so setup and hold times (Tset, Thold) are needed to prevent the loading of multiple start pulses. This would occur if
the GBST remains high during two fallings edges of the CLK signal. See Figure 7.
2.
SI starts the register scanning and the first active pixel is read out on the 83rd clock of the CLK signal. However, when multiple sensors are sequentially scanned, as in
CIS modules, the SO from the predecessor sensor becomes the SI to the subsequent sensor, hence the SI clock = the SO clock.
3.
As discussed under the third unique feature, the GBST starts the initialization process and preprocesses all sensors simultaneously in the first 82 clock cycles before the
first pixel is scanned onto the video line from the first sensor.
4.
The transition between pixels does not always reach the dark offset level as shown in the timing diagrams, see Vout. The timing diagrams show the transition doing so
for illustration purposes; however a stable pixel sampling point does exist for every pixel. The pixel transition time (ptt) shows the time when you cannot sample the pixel.
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AMIS-720658: Contact Image Sensor
Data Sheet
Figures 4 and 5 show the initialization of the first sensor in relation to its subsequent cascaded sensors. The SIC selects the first sensor
to operate with 82 clock cycles of delay by connecting it to Vdd on the first sensor and to Ground for all of the subsequent sensors,
hence the first sensor will operate with 82 inactive pixels being clocked out before its first active pixel is clocked out.
GBST
CLK
1
2
3
4
79
80
81
82
83
84
85
416
86
417
418
422
423
424
425
426
SO
VOUT
1
2
4
3
82 Inactive Pixels (82 Clocks)
334
335
336
340
341
342
343
344
344 Active Pixels (344 Clocks)
Figure 4: Overall Timing Diagram for the 600dpi Mode
GBST
CLK
1
2
3
4
79
80
81
82
83
84
85
244
86
245
246
250
251
252
253
254
SO
VOUT
1
2
82 Inactive Pixels (82 Clocks)
3
4
162
163
172 Active Pixels (172 Clocks)
Figure 5: Overall Timing Diagram for the 300dpi Mode
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164
168
169
170
171
172
AMIS-720658: Contact Image Sensor
Data Sheet
Figures 6 and 7 detail the timing of the CLK, GBST, Vout, and SI/SO signals in further detail, which have the same timing requirements
for both the 600 and 300dpi modes. The rise and fall times are listed in Table 5. In Figure 7, note that Pixel 83 is the first active pixel,
as the first 82 pixels are dummy pixels.
CLKpw
CLKpw
CLKp
50%
50%
CLK
Thold
CLKrt
Tset
CLKft
GBST
GBSTft
GBSTrt
VOUT
SI/SO
SI/SOrt
SI/SOft
Figure 6: Rise and Fall Times for both the 600/300dpi Modes
1
CLK
Thold
2
Thold
3
82
3
82
83
84
85
Tset
GBST
Tset
Video Signal (Vout)
1
2
83
Figure 7: Timing of GBST-to-first Pixel of the First Sensor for both the 600/300dpi Modes
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84
85
AMIS-720658: Contact Image Sensor
Data Sheet
Figure 8 shows the timing of a single pixel. The pixel transition time (ptt) is shown, which is time during which the pixel cannot be
sampled.
CLK
90%
VOUT
ptt
1 Pixel
Figure 8: Pixel Timing
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AMIS-720658: Contact Image Sensor
Data Sheet
Figures 9 and 10 show the timing of the SI/SO, which comes out in line with the 334th pixel for the 600dpi mode and the 162nd pixel for
the 300dpi mode. The SO from the first sensor enters as the SI clock of the second and subsequent sensors, hence all subsequent
sensors will start their register scan after each of the preceding sensors completes its scan.
th
nd
The last active pixel of each sensor is the 344 pixel for the 600dpi mode and 172 pixel for the 300dpi mode.
1st CLK of second sensor
CLK
415
416
418
417
419
425
426
1
2
1
2
CLK numbers include timing for 82 inactive pixels and 344 active pixels
SI / SO
Vout
335
334
336
337
344
343
Pixel 1 of second sensor
Last active pixel = pixel 344
SI/SO Timing for 600 dpi of first/second sensors
Figure 9: Timing of SI/SO Clock for the 600dpi Mode
1st CLK of second sensor
CLK
243
244
246
245
247
253
254
1
2
1
2
CLK numbers include timing for 82 inactive pixels and 172 active pixels
SI / SO
Vout
162
163
164
165
171
Last active pixel = pixel 172
SI/SO Timing for 300 dpi of first/second sensors
Figure 10: Timing of SI/SO Clock for the 300dpi Mode
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172
Pixel 1 of second sensor
AMIS-720658: Contact Image Sensor
9.0 Example of a CIS Module Using Cascaded AMIS-720658 Image Sensors
Figure 11 shows the proposed PCB schematic of the 15 chip CIS module.
Figure 11: CIS Module with AMIS-720658 Image Sensors
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Data Sheet
AMIS-720658: Contact Image Sensor
9.1 Parameters to be Confirmed
•
Sensitivity
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Data Sheet
AMIS-720658: Contact Image Sensor
Data Sheet
10.0 Company or Product Inquiries
For more information about AMI Semiconductor’s image sensors, please send an email to [email protected]
For more information about AMI Semiconductor’s products or services visit our Web site at http://www.amis.com.
Production Technical Data - The information contained in this document applies to a product in production. AMI Semiconductor and its subsidiaries (“AMIS”) have made every effort to ensure
that the information is accurate and reliable. However, the characteristics and specifications of the product are subject to change without notice and the information is provided “AS IS” without
warranty of any kind (express or implied). Customers are advised to obtain the latest version of relevant information to verify that data being relied on is the most current and complete. AMIS
reserves the right to discontinue production and change specifications and prices at any time and without notice. Products sold by AMIS are covered by the warranty and patent
indemnification provisions appearing in its Terms of Sale only. AMIS makes no other warranty, express or implied, and disclaims the warranties of noninfringement, merchantability, or fitness
for a particular purpose. AMI Semiconductor's products are intended for use in ordinary commercial applications. These products are not designed, authorized, or warranted to be suitable for
use in life-support systems or other critical applications where malfunction may cause personal injury. Inclusion of AMIS products in such applications is understood to be fully at the
customer’s risk. Applications requiring extended temperature range, operation in unusual environmental conditions, or high reliability, such as military or medical life-support, are specifically
not recommended without additional processing by AMIS for such applications. Copyright © 2006 AMI Semiconductor, Inc.
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