µPD3778
10. Random noise (CDS): σCDS
Random noise (CDS) σCDS is defined as the standard deviation of a valid pixel output signal with 100 times (=
100 lines) data sampling at dark (light shielding). This is measured 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 “VCDSi = VDi – VOi”.
5. Repeat the above procedure (1 to 4) for 100 times (= 100 lines).
6. Calculate the standard deviation σCDS using the following formula.
σCDS (mV) =
100
Σ (VCDSi – V)2
i=1
100
Σ 1 100
, V=
VCDSi
100 i=1
Reset feed-through
VOUT
Video output
Data Sheet S14374EJ1V0DS00
13