Rainbow Electronics TH7804A - Manual (Page 7)

7
TH7804A
1989A–IMAGE–05/02
Figure 4. CTF Typical Curves (2854 K Source)
Electro-optical Performance Without Infrared Cut-off Filtering
The TH7804A’s special semiconductor process enables it to exploit the silicon's high
near infrared sensitivity while maintaining good imaging performance in terms of
response uniformity and resolution. Typical changes in performance with and without IR
filtering are summarized below.
Complementary
Operating Modes TH7804A may be used in several configurations in regards to video output sampling and
charge sensing reset.
1. Sampling Options:
Inhibition of internal sampling pulses allows for two possibilities:
a. no sampling: video output delivered in unsampled form,
b. sampling by external clocks: external sampling pulses directly applied to
Φ
ECHA
, Φ
ECHB
inputs.
If internal sampling clocks S Φ
ECHA
and S Φ
ECHB
are not used, it is recommended of
unpower the corresponding clock drivers, as this will greatly reduce on-chip power
consumption.
2. External Reset Option:
The position and period of the charge reset clocks may be optimized by using external
clocks on
Φ
RA
and Φ
RB
inputs. This is specially interesting to optimize the video outputs
for Correlated Double Sampling (in order to reduce noise and improve S/N ratio).
Control signals to be applied in the different configurations are shown in Table 6.
With IR Cut-off Filter No IR Cut-off Filter
Average Video Signal Due to a Given Scene Illumination V
OS
V
OS
x 4
PRNU (Single Defects Excluded) ±5% ±5%
CTF at Nyquist Frequency 70% 50%