AK8448 Datasheet, PDF (42/53 Pages) Asahi Kasei Microsystems – 6-Channel Linear Sensor compatible 10 Bit 40 MSPS x 3 Analog Pre-Processor

ASAHI KASEI
[AK8448]
„ Clamp Operation
In CDS mode and Clamp mode, Clamping is made in order to adjust the reference DC
level of sensor signal to match the internal reference level of the AK8448.
Clamp operation is controlled by CLPB and SHR.
Clamp switch closes during CLPB = Low and SHR = High ( “ Low “ when SHR, SHD
polarities are inverted ), and CCDINn ( n = 0 ~ 5 ) pin signal is pulled toward the internal
clamp level.
REFINn ( n = 0 ~ 5 ) is also clamped in the same way.
In CDS mode, fix CLPB to low so that clamping is always enabled.
CCDINn Clamp Level
Sensor
CCDINn
CLPB .AND. SHR
0: Open
1: Close
CDS
(Sample
& Hold)
Figure 7 Clamp Circuit Outline
CCD
Effective Pixel
Optical Black
SHR
CLPB
Clamp is active
Internal Clamp Level
CCDINn
Pull in reference level to clamp level
Figure 8 Clamp Operation Timing Outline
Effective Pixel
MS1513-E-00
42
2013/02