TCD2704D Datasheet, PDF (5/16 Pages) Toshiba Semiconductor – High sensitive and low dark current 7500 elements x 4 line

TCD2704D
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.
video output
video output
200 ns
200 ns
∆V
pixel (n)
pixel (n + 1)
Output waveform (effective pixels under dark condition)
(1) Two adjacent pixels (pixel n and n + 1) 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 ∆V.
∆V = V (n) − V (n + 1)
(4) The standard deviation of ∆V is calculated after procedure (2) and (3) are repeated 30 times (30
readings)
∆V
=
1
30
30
∑^|
i =1
∆Vi
|
σ=
1
30
30
∑(|
i=1
∆V_i
| 㧙∆V )²
(5) Procedure (2), (3) and (4) are repeated 10 times to get sigma value.
(6) 10 sigma values are averaged.
σ
=
1
10
10
∑^σ
j=1
j
(7) σ 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_Dσ =
1
2
σ
5
2001-04-13