EL2360C
Triple 130 MHz Current Feedback Amplifier
Applications Information Ð Contd.
[ ]
[ ]
If we set the two PD
equations, 1 and 2 ,
Current Limit
MAX
equal to each other, and solve for V , we can get a
S
family of curves for various loads and output
[ ]
voltages according to 3 :
The EL2360C has internal current limits that
protect the circuit in the event of an output being
shorted to ground. This limit is set at 100 mA
nominally and reduces with the junction temper-
e
65 mA. If any one output is shorted to ground,
the power dissipation could be well over 1W, and
much greater if all outputs are shorted. Heat re-
moval is required in order for the EL2360C to
survive an indefinite short.
b
R *(T
JMAX
T
)
L
AMAX
ature. At T
150 C, the current limits at about
2
(V )
OUT
§
a
J
N*i
JA
(I *R )
e
[ ]
3
V
S
a
V
OUT
S
L
The figures below show total supply voltage V
S
vs R for various output voltage swings for the
L
PDIP and SOIC packages. The curves assume
e a
11.3 mA per amplifier. The curves do not
WORST CASE conditions of T
e
85 C and
§
Driving Cables and Capacitive Loads
A
I
S
When used as a cable driver, double termination
is always recommended for reflection-free per-
formance. For those applications, the back-termi-
nation series resistor will de-couple the EL2360C
from the cable and allow extensive capacitive
drive. However, other applications may have
high capacitive loads without a back-termination
resistor. In these applications, a small series resis-
tor (usually between 5X and 50X) can be placed
in series with the output to eliminate most peak-
include heat removal or forcing air, or the simple
fact that the package will be attached to a circuit
board, which can also provide some form of heat
removal. Larger temperature and voltage ranges
are possible with heat removal and forcing air
past the part.
Supply Voltage vs R
for Various V
L
(PDIP Package)
OUT
ing. The gain resistor (R ) can then be chosen to
G
make up for any gain loss which may be created
by this additional resistor at the output. In many
cases it is also possible to simply increase the val-
ue of the feedback resistor (R ) to reduce the
F
peaking.
2360–12
Supply Voltage vs R
for Various V
L
(SOIC Package)
OUT
2360–13
13
ELANTEC [ ELANTEC SEMICONDUCTOR ]
