Cirrus Logic CS4955 - Manual (Page 54)

CS4954 CS4955
54 DS278F6
This reduces the total power that the CS4954/5 re-
quires, and eliminates the impedance mismatch
presented by an unused connector. The analog out-
puts should not overlay the analog power plane in
order to maximize high frequency power supply re-
jection.
9.5 Analog Output Protection
To minimize the possibility of damage to the ana-
log output sections, make sure that all video con-
nectors are well grounded. The connector should
have a good DC ground path to the analog and dig-
ital power supply grounds. If no DC (and low fre-
quency) path is present, improperly grounded
equipment can impose damaging reverse currents
on the video out lines. Therefore, it is also a good
idea to use output filters that are AC coupled to
avoid any problems.
9.6 ESD Protection
All MOS devices are sensitive to Electro Static
Discharge (ESD). When manipulating these devic-
es, proper ESD precautions are recommended to
avoid performance degradation or permanent dra-
mage.
9.7 External DAC Output Filter
If an output filter is required, the low pass filter
shown in Figure
30 can be used.
2.2 μH
330pF 220pF
OUT IN
C
1
C
2
Figure 30. External Low Pass Filter
NOTE:
C
2
should be chosen so that C
1
= C
2
+ C
cable
33pF