Datasheet

75 W
S-VideoY'1Out
CVBS1Out
CVBS
R
SOC/DAC/Encoder
S-Video Y’
R
S-Video C’
R
Y'/G'
R
1
2
3
4
5
6
7
8
9
10
20
19
18
17
16
15
14
13
12
11
SD1OUT
SD2OUT
SD3OUT
DisableSD
GND
DisableHD
SF1OUT
SF2OUT
SF3OUT
BypassSF
SD1IN
SD2IN
SD3IN
NC
V
S+
NC
SF1IN
SF2IN
SF3IN
BypassSD
THS7360
Bypass
SDLPF
Bypass
SFLPF
P' /B'
B
R
P' /R'
R
R
75 W
75 W
S-VideoC'1Out
75 W
75 W
75 W
Y'/G'1Out
75 W
P’ /B'1Out
B
75 W
75 W
P' /R'1Out
R
75 W
75 W
75 W
75 W
S-VideoY'1Out
CVBS1Out
75 W
75 W
S-VideoC'1Out
75 W
75 W
75 W
Y'/G'1Out
75 W
P' /B'1Out
B
75 W
75 W
P’ /R'1Out
R
75 W
75 W
75 W
+2.7Vto
+5V
DisableSF
DisableSD
THS7360
SLOS674 –JUNE 2010 www.ti.com
(1) SF indicates selectable filter.
Figure 47. Typical Six-Channel System with DC-Coupled Line Driving and Two Outputs Per Channel
One concern of dc-coupling arises, however, if the but power and thermal analysis should always be
line is terminated to ground. If the ac-bias input examined in any system to ensure that no issues
configuration is used, the output of the THS7360 has arise. Be sure to use RMS power and not
a dc bias on the output, such as 1.6 V. With two lines instantaneous power when evaluating the thermal
terminated to ground, this configuration allows a dc performance.
current path to flow, such as 1.6 V/75 Ω = 21.3 mA.
Note that the THS7360 can drive the line with
The result of this configuration is a slightly decreased
dc-coupling regardless of the input mode of
high-output voltage swing and an increase in power
operation. The only requirement is to make sure the
dissipation of the THS7360. While the THS7360 was
video line has proper termination in series with the
designed to operate with a junction temperature of up
output (typically 75 Ω). This requirement helps isolate
to +125°C, care must be taken to ensure that the
capacitive loading effects from the THS7360 output.
junction temperature does not exceed this level or
Failure to isolate capacitive loads may result in
else long-term reliability could suffer. Using a 5-V
instabilities with the output buffer, potentially causing
supply, this configuration can result in an additional
ringing or oscillations to appear. The stray
dc power dissipation of (5 V – 1.6 V) × 21.3 mA =
capacitance that appears directly at the THS7360
72.5 mW per channel. With a 3.3-V supply, this
output pins should be kept below 20 pF for the fixed
dissipation reduces to 36.2 mW per channel. The
SD filter channels and below 15 pF for the selectable
overall low quiescent current of the THS7360 design
minimizes potential thermal issues even when using
the TSSOP package at high ambient temperatures,
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