FMS6364A Datasheet, PDF (9/12 Pages) Fairchild Semiconductor – Low-Cost Four-Channel Standard Definition (SD) & High (HD) Definition Video Filter Driver

The same method can be used for biased signals. The
Pb and Pr channels are biased to set the DC level to
500mV.
The same circuits can be used with AC-coupled outputs
if desired.
DVD or
STB
SoC
DAC
Output
0V - 1.4V
0.1μ
LCVF
Clamp
Active
75Ω ^220μ
Figure 17. AC-Coupled Inputs and Outputs
External video
source must
be AC coupled
0V - 1.4V
0.1μ
75Ω
LCVF
Clamp
Active
75Ω ^220μ
Figure 18. Biased SCART with AC-Coupled Outputs
Note:
5. The video tilt or line time distortion is dominated by
the AC-coupling capacitor. The value may need to
be increased beyond 220μF to obtain satisfactory
operation in some applications.
Power Dissipation
The FMS6364A output drive configuration must be
considered when calculating overall power dissipation.
Care must be taken not to exceed the maximum die
junction temperature. The following equations can be
used to calculate the power dissipation and internal
temperature rise.
TJ = TA + PD • JA
(1)
where:
PD = PCH1 + PCH2 + PCH3 and
(2)
PCHx = VCC • ICH - (VO2/RL)
(3)
where:
VO = 2VIN + 0.280V
(4)
ICH = (ICC/3) + (VO/RL)
(5)
VIN = RMS value of input signal
ICC = 50mA
VCC = 3.3V
RL = channel load resistance.
Board layout can also affect thermal characteristics.
Refer to the Layout Considerations section for details.
The FMS6364A is specified to operate with output
currents typically less than 50mA, more than sufficient
for a dual (75Ω) video load. Internal amplifiers are
current limited to a maximum of 100mA and should
withstand brief-duration short-circuit conditions. This
capability is not guaranteed.
© 2010 Fairchild Semiconductor Corporation
FMS6364A • Rev. 3.0.1
9
www.fairchildsemi.com