EL5164 Intersil Corporation, EL5164 Datasheet - Page 11

• Manufacturer Part Number: EL5164
• Description: 600MHz Current Feedback Amplifiers with Enable
• Manufacturer: Intersil Corporation

choice for driving isolation transformers in
telecommunications applications.
Driving Cables and Capacitive Loads
When used as a cable driver, double termination is always
recommended for reflection-free performance. For those
applications, the back-termination series resistor will
decouple the EL5164, EL5165, and EL5364 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
resistor (usually between 5Ω and 50Ω) can be placed in
series with the output to eliminate most peaking. The gain
resistor (R
loss which may be created by this additional resistor at the
output. In many cases it is also possible to simply increase
the value of the feedback resistor (R
peaking.
Current Limiting
The EL5164, EL5165, and EL5364 have no internal current-
limiting circuitry. If the output is shorted, it is possible to
exceed the Absolute Maximum Rating for output current or
power dissipation, potentially resulting in the destruction of
the device.
Power Dissipation
With the high output drive capability of the EL5164, EL5165,
and EL5364, it is possible to exceed the 125°C Absolute
Maximum junction temperature under certain very high load
current conditions. Generally speaking when R
about 25Ω, it is important to calculate the maximum junction
temperature (T
power supply voltages, load conditions, or package type
need to be modified for the EL5164, EL5165, and EL5364 to
remain in the safe operating area. These parameters are
calculated as follows:
T
where:
• T
• θ
• n = Number of amplifiers in the package
• PD
PD
PD
JMAX
the package
MAX
MAX
JA
MAX
MAX
= Thermal resistance of the package
=
for each amplifier can be calculated as follows:
=
= Maximum ambient temperature
T
2 (
G
= Maximum power dissipation of each amplifier in
MAX
) can then be chosen to make up for any gain
×
V
JMAX
+
S
(
×
θ
JA
I
SMAX
) for the application to determine if
×
n
×
)
PD
+
11
(
MAX
V
S
–
)
V
OUTMAX
F
) to reduce the
)
×
L
EL5164, EL5165, EL5364
V
--------------------------- -
falls below
OUTMAX
R
L
where:
• V
• I
• V
• R
Typical Application Circuits
FIGURE 23. INVERTING 200mA OUTPUT CURRENT
SMAX
S
OUTMAX
L
FIGURE 24. FAST-SETTLING PRECISION AMPLIFIER
= Load resistance
= Supply voltage
= Maximum supply current of 1A
V
IN
V
= Maximum output voltage (required)
375Ω
IN
DISTRIBUTION AMPLIFIER
375Ω
375Ω
375Ω
IN+
IN+
IN-
IN-
+5V
+5V
-5V
-5V
IN+
IN+
IN-
IN-
+5V
+5V
-5V
-5V
375Ω
375Ω
V
V
V
V
375Ω
S
S
S
S
+
-
+
-
V
V
V
V
OUT
OUT
S
S
S
S
0.1µF
0.1µF
0.1µF
0.1µF
+
-
+
-
0.1µF
OUT
0.1µF
0.1µF
OUT
0.1µF
5Ω
5Ω
V
OUT
V
OUT