UPD8870 Datasheet, PDF (14/24 Pages) NEC – 10680 PIXELS × 3 COLOR CCD LINEAR IMAGE SENSOR

µ PD8870
9. Register imbalance : RI
The rate of the difference between the averages of the output voltage of Odd and Even pixels, against the
average output voltage of all the valid pixels.
2
n
RI (%) =
n
2
∑ (V2j –1 – V2j)
j=1
n
∑ ¹
n ^Vj
j=1
× 100
n : Number of valid pixels
Vj : Output voltage of valid pixel number j
10. Random noise (CDS) : σ CDS
Random noise σ CDS is defined as the standard deviation of a valid pixel output signal with 100 times (=100
lines) data sampling at dark (light shielding). σ CDS is calculated by the following procedure.
1. One valid photocell in one reading is fixed as measurement point.
2. The output level is measured during the reset feed-through period which is averaged over 100 ns to get
“VDi”.
3. The output level is measured during the video output time averaged over 100 ns to get “VOi”.
4. The correlated double sampling output is defined by the following formula.
VCDSi = VDi – VOi
5. Repeat the above procedure (1 to 4) for 100 times (= 100 lines).
6. Calculate the standard deviation σ CDS using the following formula equation.
σ CDS (mV) =
100
Σ ^{(VCDSi – V)2}
i=1
100
Σ ^{1 100}
, V=
VCDSi
100 _{i = 1}
Reset feed-through
Video output
14
Data Sheet S15328EJ2V0DS