Rainbow Electronics TH7888A - Manual (Page 9)

EXPOSURE TIME REDUCTION
TH7888A allows exposure time control (electronic shutter function).
The exposure time reduction is achieved by pulsing all the F Pi gates to 0 volt so as to remove continuously all the photoge-
nerated electrons through antiblooming drain VA.
Figure 10 : Timing diagram for electronic shutter
TABLE 2 - DRIVE CLOCK CHARACTERISTICS
Parameter Symbol Value Unit Remarks
Min Typ Max
Image zone clocks F P1,2, 3,4
Typical input capacitance
15 nF
See figure 11
High level 7.5 8 8.5 V
Low level 0 0.5 0.8 V
Memory zone clocks F M1,2,3,4
Typical input capacitance
15.5 nF
See figure 11
High level 7.5 8 8.5 V
Low level 0 0.5 0.8 V
Memory to register clocks F M
Typical input capacitance
10 pF
High level 8.5 9 9.5 V
Low level 0 0.5 0.8 V
Antiblooming gate F A
Typical input capacitance
14 nF
See figures 11 & 13
High level (integration) 3 4 7 V
Low level (transfer) 0 0.5 0.8 V
Reset gate
F
R
Typical input capacitance
10 pF
High level 10 12 13 V
Low level 0 2 3 V
Readout register clocks F L1,2
High level 8.5 9 9.5 V
Low level 0 0.5 0.8 V
Maximum readout register frequency FH 20 23 MHz See figure 7
Image zone to memory zone transfer
frequency
FV 1.25 1.7 MHz See figure 12
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TH7888A
Fall times & rise times : see fig. 5 & 6