EL4453C
Video Fader
Contd
For instance the EL4453C draws a maximum of
%
and the
21 mA With light loading R
PAR
dissipation with
g
5V supplies is 210 mW The
maximum supply voltage that the device can run
on for a given P
D
and the other parameters is
Power Supplies
x
This allows
g
15V operation over the commercial
temperature range but higher ambient tempera-
ture or output loading may require lower supply
voltages
Output Loading
The output stage of the EL4453C is very power-
ful It typically can source 80 mA and sink
120 mA Of course this is too much current to
sustain and the part will eventually be destroyed
by excessive dissipation or by metal traces on the
die opening The metal traces are completely reli-
able while delivering the 30 mA continuous out-
put given in the Absolute Maximum Ratings ta-
ble in this data sheet or higher purely transient
currents
Gain changes only 0 2% from no load to 100X
load Heavy resistive loading will degrade fre-
quency response and video distortion for loads
k
100X
Capacitive loads will cause peaking in the fre-
quency response If capacitive loads must be driv-
en a small-valued series resistor can be used to
isolate it 12X to 51X should suffice A 22X series
resistor will limit peaking to 2 5 dB with even a
220 pF load
V
S
max
e
(P
D
a
V
O2
R
PAR
) (2I
S
a
V
O
R
PAR
)
The maximum dissipation a package can offer is
P
D
max
e
(T
D
max
b
T
A
max)
i
JA
where T
D
max is the maximum die tempera-
ture 150 C for reliability less to retain
optimum electrical performace
T
A
max is the ambient temperature 70 C
for commercial and 85 C for industrial
range
i
JA
is the thermal resistance of the
mounted package obtained from data-
sheet dissipation curves
The more difficult case is the SO-14 package
With a maximum die temperature of 150 C and a
maximum ambient temperature of 70 C the 80 C
temperature rise and package thermal resistance
of 110 W gives a dissipation of 636 mW at 85 C
11
ELANTEC [ ELANTEC SEMICONDUCTOR ]
