ncs2561 ON Semiconductor, ncs2561 Datasheet - Page 8

• Manufacturer Part Number: ncs2561
• Description: 3.3v Single Channel Video Driver With Recontruction Filter And Sag Correction
• Manufacturer: ON Semiconductor

even as the value increases. A value of 22 mF is
recommended for optimal performance.
capacitor value Cout = 220 mF (no sag) the nominal
equivalent sag combination is Csag = 22 mF and Cout =
67 mF. A value of 47 mF for Cout will yield equivalent
results. If we consider a coupling cap of 470 mF, the best
compromise for sag combination is Csag = 22 mF and Cout
= 100 mF. A value of 67 mF for Cout will yield equivalent
results.
Video
DAC
The Csag value has no significant impact on the coupling
To achieve similar behavior to an output coupling
Figure 13. No sag, Cout = 220 mF
1 V
0 V
(Top : Input, Bottom : Output)
Rs
IN
NCS2561
Figure 15. NCS2561 in an AC-Coupled Configuration with no sag
Shifter
Level
2-pole
filter
GND
2.7V to 3.3V
Vcc
Vcc
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NCS2561
+
-
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capacitor on a video signal corresponding to a worst case
situation regarding the low frequency bandwidth. The video
signal used is a 50 Hz 1/2 black - 1/2 white video pattern.
This signal is obtained using the PAL Flat Field Square wave
signal option available with the video generator TG700 from
Tektronix. These measurements show how the sag function
can help to reduce the field tilt problem using lower value
coupling capacitor than traditional approach.
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Figures 13 and 14 show the impact of the output coupling
Figure 14. Csag = 22 mF, Cout = 47 mF
SAG
OUT
(Top : Input, Bottom : Output)
220mF / 470mF
75 W
TV
75 W