KAI−04070
Global Peak to Peak Non-Uniformity
Bright Field Defect Test
This test is performed with the imager illuminated to
a level such that the output is at 70% of saturation
(approximately 924 mV). Prior to this test being performed
the substrate voltage has been set such that the charge
capacity of the sensor is 1,320 mV. The sensor is partitioned
into 256 sub regions of interest, each of which is 128 by 128
pixels in size. The average signal level of each of the 256 sub
regions of interest (ROI) is calculated. The signal level of
each of the sub regions of interest is calculated using the
following formula:
This test is performed with the imager illuminated to
a level such that the output is at approximately 924 mV.
Prior to this test being performed the substrate voltage has
been set such that the charge capacity of the sensor is
1,320 mV. The average signal level of all active pixels is
found. The bright and dark thresholds are set as:
Dark Defect Threshold = Active Area Signal @ Threshold
Bright Defect Threshold = Active Area Signal @ Threshold
The sensor is then partitioned into 256 sub regions of
interest, each of which is 128 by 128 pixels in size. In each
region of interest, the average value of all pixels is found.
For each region of interest, a pixel is marked defective if it
is greater than or equal to the median value of that region of
interest plus the bright threshold specified or if it is less than
or equal to the median value of that region of interest minus
the dark threshold specified.
Signal of ROI[i] + (ROI Average in Counts *
* Horizontal Overclock Average in Counts) @
@ mV per Count
Where i = 1 to 256. During this calculation on the 144 sub
regions of interest, the maximum and minimum signal levels
are found. The global peak to peak uniformity is then
calculated as:
• Example for major bright field defective pixels:
• Average value of all active pixels is found to be 924 mV
• Dark defect threshold: 924 mV ⋅ 12% = 111 mV
• Bright defect threshold: 924 mV ⋅ 12% = 111 mV
Max. Signal * Min. Signal
Global Uniformity + 100 @ ǒ
Ǔ
Active Area Signal
Units : % pp
• Region of interest #1 selected. This region of interest is
Center Non-Uniformity
pixels 17, 17 to pixels 144, 144
This test is performed with the imager illuminated to
a level such that the output is at 70% of saturation
(approximately 924 mV). Prior to this test being performed
the substrate voltage has been set such that the charge
capacity of the sensor is 1,320 mV. Defects are excluded for
the calculation of this test. This test is performed on the
center 100 by 100 pixels of the sensor. Center uniformity is
defined as:
♦ Median of this region of interest is found to be
920 mV
♦ Any pixel in this region of interest that is
≤ (920 − 111 mV) 809 mV in intensity will be
marked defective
♦ Any pixel in this region of interest that is
≥ (920 + 111 mV) 1,031 mV in intensity will be
marked defective
Center ROI Standard Deviation
• All remaining 144 sub regions of interest are analyzed
for defective pixels in the same manner
Center ROI Uniformity + 100 @ ǒ
Ǔ
Center ROI Signal
Units : % rms
Center ROI Signal = Center ROI Average − Dark Colum Average
Dark Field Defect Test
This test is performed under dark field conditions.
The sensor is partitioned into 256 sub regions of interest,
each of which is 128 by 128 pixels in size. In each region of
interest, the median value of all pixels is found. For each
region of interest, a pixel is marked defective if it is greater
than or equal to the median value of that region of interest
plus the defect threshold specified in the “Detect
Definitions” section.
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