AMIS-720233-B: Contact Image Sensor
Data Sheet
1.0 General Description
The AMIS-720233-B (PI3033B) contact image sensor (CIS) chip is a 200 dot per inch (dpi) resolution, linear array image sensor chip.
The sensor chip is processed with AMI Semiconductor’s proprietary CMOS image sensing technology. Designed for cascading multiple
chips in a series, the image sensor chips, using chip-on-board process, are bonded end-to-end on a printed circuit board (PCB) in
varying sensing array lengths. This CIS chip offers image reading widths to suit document scanners found in facsimile, scanner, check
reader and office automation equipment.
Figure 1 is a block diagram of the imaging sensor chip. Each sensor chip consists of 64 detector elements, their associated multiplexing
switches, buffers and a chip selector. The detector's element-to-element spacing is approximately 125um. The size of each chip without
scribe lines is 7950um by 500um. Each sensor chip has eight bonding pads. Only seven are used to make the CIS modules. The pad
symbols and functions are described in Table 1.
7950
m
Row of 64 Sensors
and Video Signal
Multiplexers
500
Readout Shift Register
Buffer
SP
Chip
Select
Buffer
CP
VDD DGND
IOUT
Buffer
RSTLEV
Figure 1: AMIS-720233-B Block Diagram
Table 1: Pad Symbols and Functions
Symbol
Function
SP
Start pulse: input to start the line scan
CP
Clock pulse: input to clock the shift register
VDD
Positive supply: +5V supply connected to substrate
DGND
Digital ground: connection topside common
RSTLEV
A bias pad: not used, left floating
IOUT
Signal current output: output for video signal current
AGND
Analog ground: connection topside common
EOS
End-of-scan pulse: output from the shift register at end-of-scan
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AGND EOS
m
AMIS-720233-B: Contact Image Sensor
Data Sheet
2.0 Bonding Pad Outputs Locations and Die Dimensions
Figure 2 shows image sensors die dimension and the bonding pad locations for the AMIS-720233-B sensor chip. The location is
referenced to the lower left corner of the die. Note RSTLV, bias pad is not used.
Figure 2: Bonding Pad and Chip Layout
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AMIS-720233-B: Contact Image Sensor
3.0 Wafer Scribe Lines
Figure 3 shows the wafer scribe lines bordering the AMIS-720233-B sensor chip. The wafer thickness is 350µm.
Figure 3: Wafer Scribe Lines
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Data Sheet
AMIS-720233-B: Contact Image Sensor
Data Sheet
4.0 Electro-Optical Characteristics (25°C)
The electro-optical characteristics of AMIS-720233-B imaging sensor chip are listed in Table 2. These values are measured at 25°C.
Table 2: Electro-Optical Characteristics
Parameters
Number of photo-elements
Pixel-to-pixel spacing
Line scanning rate
Clock frequency
Output voltage
Output voltage non-uniformity
Dark output voltage
Dark output non-uniformity
Adjacent pixel non-uniformity
Chip-to-chip non-uniformity
Notes:
1.
2.
3.
4.
5.
6.
7.
8.
9.
Symbols
(1)
Tint
(2)
Fclk
(3)
Vpavg
(4)
Up
(5)
Vd
(6)
Ud
(7)
Upadj
(8)
Ucc
Typical
64
125
864
2.0
Units
Elements
µm
µs/line
MHz
1.0
± 7.5
<20
<10
<7.5
± 7.5
V
%
mV
mV
%
%
Notes
See Note 2 for higher clock speed.
(maximum 5MHz)
–2
2
Exp = 1.8 X 10 µJ/cm
Notes 5 & 3
Notes 6 & 3
Tint stands for the line scanning rate or the integration time. It is determined by the time interval between two SPs.
Fclk stands for the input clock frequency. For Fclk > 2.0MHz see Note 3 and the Section 5.
Vpavg = ∑Vp(n)/Npixels (average level in one line scan).
Where Vp(n) is the amplitude of nth pixel in the sensor chip and Npixels is the total number of pixels in sensor chip. Vpavg is converted from impulse current video
pixel into a voltage output (see Figure 4 and
Figure 5).
Exp = LP x Tint, where LP is light power (Yellow-Green) and tint is as defined above (see Figure 6).
Up is the uniformity specification, measured under a uniform exposing light exposure. Up = [Vp(max) - Vpavg] / Vpavg x 100% or [Vpavg - Vp(min)] / Vpavg} x
100%, whichever is greater.
Where Vp(max) is the maximum pixel output voltage in the light.
Vp(min) is the minimum pixel output voltage in the light.
Vd = ∑Vp(n)/Npixels. Where Vp(n) is the pixels signal amplitude of the nth pixel of the sensor. Dark is where the sensor is placed in the dark environment.
Ud = Vdmax – Vdmin. Dark is same definition as above.
Upadj = MAX[ | (Vp(n) - Vp(n+l) | / Vp(n)) x 100%. Upadj is the non-uniformity in percentage. It is the amplitude difference between two neighboring pixels.
Ucc is the uniformity specifications, measured among the good die on the wafer. Under uniform light exposure the sensors are measured and calculated with
following algorithm: Vpavg of all the good dies on the wafer are averaged and assigned VGpavg. Then the die with maximum Vpavg is assigned Vpavg(max),
and the one with minimum Vpavg is assigned Vpavg(min). Then UCC = {[Vpavg(max)-Vpavg(min)]/VGpavg}x100.
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AMIS-720233-B: Contact Image Sensor
Data Sheet
5.0 Output Circuit of the Image Sensor
The video signal from each photo-site is connected to a common video line on the sensor. Each photo-site is composed of a
phototransistor with a series MOS switch connecting its emitter to a common video line. The video line is connected to the pad labeled
IOUT. The photo-sensing element is the base of the phototransistor where it detects and converts the light energy to proportional
charges and stores it in its base capacitance. When the MOS switch is activated, the emitter is connected to the video line and acts as
source follower, producing an impulse current proportional to the stored charges in the base. This current is a discrete-time analog
signal output called the video pixel. Accordingly, the video pixel is proportional to the light energy impinging in the neighborhood of its
photo-sites. Figure 4, shows the output structure of four photo-sites out of 64. The multiplexing MOS switch in each photo-site
terminates into the output pad, IOUT, through a common video line. The shift register sequentially accesses each photo-site by a
activating the MOS switch. As they are accessed, a sequence of video pixels is sent to the IOUT where they are processed with an
external signal conversion circuit.
Figure 4: Video Pixel Output Structures
5.1 Signal Conversion Circuit
Figure 5: Video Output Test and Application Circuit
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AMIS-720233-B: Contact Image Sensor
Data Sheet
Figure 5 shows a simply circuit that provides the cleanest technique in processing the video output. It integrates all the currents from
each pixel element onto a capacitor (CAP). Then the CAP is reset to zero volts by activating the shunt switch (SW) and connecting the
video line to ground prior to accessing the following pixel element. Simultaneous to SW activation, the pixel element storage is reset to
the dark level, hence initialized for the new pixel integration process. Since this process sums the switch edges and signal current
pulses onto the CAP, it minimizes the switching patterns on the video pixels. The summed charges stored in the CAP produces a pixel
voltage with amplitude proportional to the charge from the current pulse. Since switching energies are high frequencies components,
they tend to integrate to a 0 value and the remainder adds a constant value to the dark level. The signal pixels Vp(n) is referenced to
the dark level as it is seen in Figure 6, which depicts the typical pixel waveform.
Figure 6: Single Pixel Video Output
To measure these device’s parameters the value of the CAP is set to 100pf. This value includes the stray capacitance of the video line.
The value of RIN in the amplifier circuit is set to infinity before it is removed and accordingly, the amplifier gain is one, therefore serving
as a buffer amplifier, EL2044, AD8051 or its equivalent, to isolate the video line.
Since the output is specified with a light exposure, the video output is specified with a fixed exposure. However, exposure is a function
of power and time, Exp = Light power x the tint, as well as its color. Accordingly, the AMIS-720233-B is measured with a Yellow-Green
LED light source. See Figure 7.
Note: The value of 100pf is selected because the typical PCB layout of an A6 length module has a video line capacitance, including the
stray, in the order of 100pf. The A6 length CIS module uses 13 sensor chips. See Figure 9.
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AMIS-720233-B: Contact Image Sensor
Data Sheet
Vpavg Output As A Function Of Exposure
3.000
Vpavg (Volts)
2.500
2.000
1.500
1.000
0.500
0.000
8.00E-02
7.00E-02
6.00E-02
5.00E-02
4.00E-02
3.00E-02
2.00E-02
1.00E-02
0.00E+00
Exposure (MicroJoules/cm^2)
Figure 7: Vpavg as a Function of Exposure
6.0 Absolute Maximum Ratings
Table 3: Absolute Maximum Ratings
Parameters
Power supply voltage
Power supply current
Input clock pulse (high level)
Input clock pulse (low level)
Operating temperature
Operating humidity
Storage temperature
Storage humidity
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Symbol
VDD
IDD
Vih
Vil
Top
Hop
Tstg
Hstg
Maximum Rating
10
<2.0
Vdd + 0.5
-0.25
0 to 50
10 to 85
-25 to 75
10 to 90
7
Units
V
mA
V
V
°
C
RH %
°
C
RH %
AMIS-720233-B: Contact Image Sensor
Data Sheet
7.0 Recommended Operating Conditions at Room Temperature
Table 4: Recommended Operating Conditions at Room Temperature
Parameters
Symbol
Power supply
VDD
(1)
Input clock pulses high level
Vih
(1)
Input clock pulse low level
Vil
(2)
Operating high level exposed output
IOUT
(3)
Clock frequency
Fclk
(4)
Clock pulse duty cycle
Duty
Clock pulse high durations
tw
Integration time
Tint
Operating temperature
Top
Notes:
1.
2.
3.
4.
Min.
4.5
3.0
0
0.1
Typ.
5.0
5.0
0
See Note 2
2.0
25
0.125
0.864
25
Max.
5.5
VDD
0.8
Units
V
V
V
5.0
MHz
%
µsec
ms
°
C
10
50
Applies to both CP and SP
The output is a current that is proportional to the charges, which are integrated on the phototransistor’s base via photon-to-electron conversion. For its conversion
to voltage pixels see Figure 4.
Although the clock frequency, Fclk, will operate the device at less than 100kHz, it is recommended that the device be operated above 500kHz to avoid
complication of leakage current build-up. In applications using long CIS module length, such as an array of image sensor > 27, increases in the readout time, i.e.,
increases tint, hence, leakage current build-up occurs.
The clock duty cycle is normally set to 25 percent. However, it can operate with duty cycle as large as 50 percent, which will allow more reset time at the expense
of video pixel readout time.
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AMIS-720233-B: Contact Image Sensor
Data Sheet
8.0 Switching Characteristics at 25°C
The timing relationships of the video output voltage and its two input clocks, the start pulse (SP) and the shift register clock (CP), along
with the shift register EOS output clock, are shown in Figure 8. The switch timing specification for the symbols on the timing diagram is
given in Table 5. The digital clocks' levels are +5V CMOS compatible. The video, IOUT, is specified in Figure 4.
Figure 8: Timing Diagram of the AMIS-720233-B Sensor
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AMIS-720233-B: Contact Image Sensor
Table 5: Timing Symbol's Definition
Item
Clock cycle time
(1)
Clock pulse width
Clock duty cycle
Data setup time
Data hold time
(2)
Prohibit crossing time
EOS rise delay
EOS fall delay
(3)
Signal delay time
(3)
Signal settling time
Notes:
1.
2.
3.
Symbol
to
tw
tds
tdh
tprh
terdl
tefdl
tdl
ts/h
Min.
200
50
25
20
20
Mean
Max.
10000
50
75
20
60
70
20
120
Data Sheet
Units
ns
ns
%
ns
ns
ns
ns
ns
ns
ns
Since the clock pulse width varies with the frequency, tw will vary according to duty cycle.
Prohibit crossing time is to insure that no two SPs are locked into the shift register for any single scan time. Since the SP is entered into the shift register during its
active high level when the CP clock edges falls, the active high of the SP is permitted only during one falling, CP clock edges for any given scan. Otherwise,
multiple SPs will load into the shift register.
Pixel delay times and settling time depend on the output amplifier, which is employed. These values, tdl and ts/h, are measured with the amplifier see in Figure 9
using the AMIS-720233-B sensors. Note: The impulse signal current out of the device has pulse width ~ 30ns. Hence, the faster the amplifier with a faster settling
time will yield a signal video pulse with faster rise and settle times.
9.0 Typical A6 CIS Module Circuit
Figure 9 depicts a typical A6 CIS module circuit using the AMIS-720233-B sensors. The circuit is provided as a reference to illustrate
the interconnection of the AMIS-720233-B with a serially cascaded line of image sensors. It is a typical A6 size CIS module produced
by AMIS. It provides the first-time user with additional insight for designing a CIS module and supplements the circuit descriptions
given in Section 5.
The difference is in the arrangement of the two shunt switches - U2D and U2A. U2D is a counterpart to SW in
Figure 5. A DC restoration capacitor, C20, with value of 100pf is added between the shunt’s switch. The first, U2D, clamps the video
line to ground to reset the image sensors. Simultaneously the second, U2A, clamps the node between C20 and amplifier input to an
output reference bias voltage that is on the node between R4 and R9. These resistors are voltage dividers that set the DC operating
level of the amplifier’s output by applying same bias voltage to both inputs of the amplifier. See Figure 9.
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AMIS-720233-B: Contact Image Sensor
Figure 9: Typical A6 CIS Module Circuit
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Data Sheet
AMIS-720233-B: Contact Image Sensor
Data Sheet
10.0 Company or Product Inquiries
For more information about AMI Semiconductor, our technology and our product, visit our Web site at: http://www.amis.com
North America
Tel: +1.208.233.4690
Fax: +1.208.234.6795
Europe
Tel: +32 (0) 55.33.22.11
Fax: +32 (0) 55.31.81.12
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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