Datasheet

AD9920A
Rev. B | Page 62 of 112
SUBCK PROGRAMMABLE SETTINGS:
1. PULSE POLARITY USING THE SUBCK_POL REGISTER.
2. NUMBER OF PULSES WITHIN THE FIELD USING THE SUBCKNUM REGISTER (SUBCKNUM = 3 IN THIS EXAMPLE).
3. PIXEL LOCATION OF PULSE WITHIN THE LINE AND PULSE WIDTH PROGRAMMED USING THE SUBCK_TOG1 TOGGLE POSITION REGISTER.
VD
SUBCK
t
EXP
VSG
HD
t
EXP
06878-081
Figure 81. Normal SUBCK Operation
VD
S
UBCK
NOTES
1. SECOND SUBCK PULSE IS ADDED IN THE LAST SUBCK LINE.
2. LOCATION OF SECOND PULSE IS FULLY PROGRAMMABLE USING THE SUBCKHP TOGGLE POSITION REGISTERS.
VSG
HD
t
EXP
t
EXP
0
6878-082
Figure 82. High Precision SUBCK Operation
VD
SUBCK
VSG
TRIGGE
R
EXPOSURE
(0x70)
t
EXP
NOTES
1. SUBCK CAN BE SUPPRESSED FOR MULTIPLE FIELDS BY PROGRAMMING THE EXPOSURE REGISTER TO BE GREATER THAN 0.
2. THIS EXAMPLE USES EXPOSURE = 1.
3. TRIGGER REGISTER MUST ALSO BE USED TO START THE LOW SPEED EXPOSURE.
4. VD/HD OUTPUTS CAN ALSO BE SUPPRESSED USING THE VDHD_MASK REGISTER = 1.
06878-083
Figure 83. Low Speed SUBCK Operation (SUBCKMASK_SKIP1 = 1)