EL4093C Elantec Semiconductor, Inc. (acquired by Intersil), EL4093C Datasheet - Page 15

• Manufacturer Part Number: EL4093C
• Description: 300MHz Dc-restored Video Amplifier
• Manufacturer: Elantec Semiconductor, Inc. (acquired by Intersil)

Applications Information
If the video does not contain any AC components
during the autozero level (e g RGB video) then
the above networks are not needed and the CFA
output can be connected directly to the S H in-
put
Power Dissipation
The EL4093 current feedback amplifier has an
absolute maximum of
drive This is slightly more than the current re-
quired to drive
the junction temperature is raised in this worst
case we refer to the equations below
T
where
T
PD
PD
can be calculated as follows
PD
JA
JMAX
MAX
MAX
MAX
MAX
e
e
for either the CFA or the S H amplifier
(2 V
a
e
e
e
T
(V
Maximum Ambient Temperature
Thermal Resistance of the Package
Maximum Power Dissipation of the
CFA and S H amplifier in the Pack-
age
MAX
S
S
b
g
V
2V into 75
a
I
OUTMAX
SMAX
(
JA
g
)
) (V
30 mA output current
PD
OUTMAX
To see how much
MAX
)
R
L
Contd
)
300 MHz DC-Restored Video Amplifier
15
where
V
I
V
R
For the EL4093 the maximum supply current is
11 5 mA on V
case the CFA output swings
Since the S H has a current output we assume
that it is at maximum current swing (
but at a mid-rail output voltage (0V) With the
above assumptions PD
223 mW and using the thermal resistance of a
narrow SO package (120 C W) this yields a tem-
perature increase of 27 C Since the maximum
ambient temperature is 85 C the resulting junc-
tion temperature of 112 C is still below the maxi-
mum
Please note that there is no short-circuit protec-
tion on the EL4093 CFA output and hence the
minimum short circuit current (60 mA) is greater
than the absolute maximum output current
Maintaining the EL4093 in this state for more
than a few seconds may cause the part to exceed
T
SMAX
S
OUTMAX
JMAX
L
in addition to metal migration problems
e
e
e
e
S
e
Supply Voltage
Maximum Supply Current of
Amplifier
Maximum Output Voltage of
Application
Load Resistance
g
5V Assume that in the worst
MAX
EL4093C
for the EL4093 is
g
2V into 75
g
5 5 mA)