AMIS-720649 Datasheet, PDF (3/10 Pages) AMI SEMICONDUCTOR – Contact Image Sensor

AMIS-720649: Contact Image Sensor
Data Sheet
4.4 Power Saving
Each sensor incorporates a power-saving feature when multiple sensors are cascaded together to form a linear imaging array. The SIC
on each sensor selects a unique feature of powering up a particular sensor’s output amplifier when it’s selected and powering it down
when not selected. For the AMIS-720649, only the first sensors’ amplifier is used and all subsequent sensors have their amplifiers
turned off. The pixels from each sensor are transferred onto a common video line which is connected to the amplifier of the first sensor.
The advantage of using only one active amplifier is two-fold; saving on power consumption and reducing sensor-to-sensor FPN.
4.5 Common Reference Voltage Between Cascaded Sensors
Each sensor has an input/output bias control (VR), which serves as an offset voltage reference. Each bias control pad is connected to
an internal bias source and 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.
5.0 Functional Description
5.1 Input / Output Terminals
The AMIS-720649 image sensor has 13 input and output (I/O) pads. Their symbols and function descriptions are listed in Table 1.
Table 1: Input and Output Terminals
Symbol
I/O Description
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)
SI
I
Start pulse:
Input to start a line scan. (See discussion of the sensors unique features for further details)
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)
CLK
I
Clock:
Clock input for the shift register.
AVDD
I Analog power supply
DVDD
I Digital power supply
AVSS
I Analog signal ground
DVSS
I Digital signal ground
VOUT
O
Video output voltage:
Output video signal from the amplifier.
OR
O Differential reference output
OS
O Differential video output
VR
I Reference voltage: Reference input voltage for the amplifier output, sets the output’s reset (dark) level.
SO
O
End of scan pulse:
Output from the shift register at the end of a scan.
AMI Semiconductor – Dec. 05, M-20488-001
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