TCD2905D Datasheet, PDF (5/22 Pages) Toshiba Semiconductor – CCD Image Sensor CCD (charge coupled device)

TCD2905D
Note 10: Random noise is defined as the standard deviation (sigma) of the output level difference between two
adjacent effective pixels under no illumination (i.e. dark conditions) calculated by the following procedure.
Output waveform
(effective pixels under
dark condition)
video output
200 ns
video output
200 ns
DV
pixel (n)
pixel (n + 1)
(1) Two adjacent pixels (pixel n and n + 1) after reference level clamp in one reading are fixed as
measurement points.
(2) Each of the output level at video output periods averaged over 200 ns period to get V (n) and V (n + 1).
(3) V (n + 1) is subtracted from V (n) to get DV.
DV = V (n) - V (n + 1)
(4) The standard deviation of DV is calculated after procedure (2) and (3) are repeated 30 times (30
readings).
DV
=
1
30
30
Ã¥ ^DVi
i =1
s=
1
30
30
Ã¥(
i =1
DV_i－DV
)²
(5) Procedure (2), (3) and (4) are repeated 10 times to get sigma value.
(6) 10 sigma values are averaged.
s
=
1
10
10
Ã¥^s
j=1
j
(7) I value calculated using the above procedure is observed 2 times larger than that measured
relative to the ground level. So we specify random noise as follows.
N_Ds =
1
2
s
5
2002-04-03