AMIS-720658 Datasheet, PDF (8/15 Pages) AMI SEMICONDUCTOR – Contact Image Sensor

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
Symbol
Min. Typ. Max.
Units
Clock (CLK) period
CLKp
330
ns
Clock (CLK) pulse width
CLKpw
165
ns
Clock (CLK) duty cycle
Data setup time ⁽¹⁾
50
%
Tset
20
ns
Data hold time ⁽¹⁾
Thold
25
ns
Clock (CLK) rise time ⁽²⁾
CLKrt
35
ns
Clock (CLK) fall time ⁽²⁾
CLKft
30
ns
End-of-scan (SO) rise time ⁽²⁾
SOrt
50
ns
End-of-scan (SO) fall time ⁽²⁾
SOft
50
ns
Global start (GBST) rise time ⁽³⁾
GBSTrt
35
ns
Global start (GBST) fall time ⁽³⁾
GBSTft
30
ns
Pixel transition time ⁽⁴⁾
ptt
155
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 83^rd 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.
AMI Semiconductor – Jul 06, M-20503-007
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