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IC-LF1401 Datasheet, PDF (7/10 Pages) List of Unclassifed Manufacturers – 128x1 Linear Image Sensor
iC-LF1401
128x1 LINEAR IMAGE SENSOR
DESCRIPTION OF FUNCTIONS
Rev B1, Page 7/10
Normal operation
Following an internal power-on reset the integration
and hold capacitors are discharged and the sample
and hold circuit is set to sample mode. A high signal
at SI and a rising edge at CLK triggers a readout cycle
and with it a new integration cycle.
In this process the hold capacitors of pixels 1 to 127
are switched to hold mode immediately (SNH = 1),
with pixel 128 (SNH128 = 1) following suit one clock
pulse later. This special procedure allows all pixels to
be read out with just 128 clock pulses. The integration
capacitors are discharged by a one clock long reset
signal (NRCI = 0) which occurs between the 2nd and
3rd falling edge of the readout clock pulse (cf. Figure
4). After the 127 pixels have been read out these are
again set to sample mode (SNH = 0), likewise for pixel
128 one clock pulse later (SNH128 = 0).
126 127 128 1
2
3
4
...
CLK
127 128 1
2
SI
V(AO)
Pix126 Pix127 Pix128 Pix1
Pix2
Pix3
...
Pix127 Pix128 Pix1
SNH
SNH128
NRCI
integration time pixel 1−127
integration time pixel 128
Figure 4: Readout cycle and integration sequence
If prior to the 128th clock pulse a high signal occurs
at SI the present readout is halted and immediately
reinitiated with pixel 1. In this instance the hold ca-
pacitors retain their old value i.e. hold mode prevails
(SNH/SNH128 = 0).
126 127 128 1
2
3
4
5
1
2
3
4
...
128 1
2
CLK
SI
V(AO)
SNH
SNH128
NRCI
Pix126 Pix127 Pix128 Pix1
Pix2
Pix3
Pix4
Pix5 Pix1
Pix2
Pix3
Pix4
... Pix128 Pix1
Figure 5: Restarting a readout cycle