Datasheet TCD2905CF (Toshiba) - 6

TCD2905CF 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 Output waveform (effective pixels under 200 ns dark condition) 200 ns ∆V 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 ∆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). 30 1 30 ∆V = ∑ ∆Vi σ = 1 ∑(∆Vi ∆ 2 − V ) 30 i=1 30 i=1 (5) Procedure (2), (3) and (4) are repeated 10 times to get sigma value. (6) 10 sigma values are averaged. 10 σ = 1 ∑σj 10 j=1 (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. = 1 ND σ σ 2 6 2003-2-3