EL5462ISZ Intersil, EL5462ISZ Datasheet - Page 7

• Manufacturer Part Number: EL5462ISZ
• Description: IC AMP LOW PWR 500MHZ 14-SOIC
• Manufacturer: Intersil

Specifications of EL5462ISZ

• Amplifier Type: Current Feedback
• Number Of Circuits: 4
• Slew Rate: 4000 V/µs
• -3db Bandwidth: 500MHz
• Current - Input Bias: 2µA
• Voltage - Input Offset: 1500µV
• Current - Supply: 1.5mA
• Current - Output / Channel: 100mA
• Voltage - Supply, Single/dual (±): 5 V ~ 12 V, ±2.5 V ~ 6 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 14-SOIC (3.9mm Width), 14-SOL
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Output Type: -
• Gain Bandwidth Product: -

Feedback Resistor Values
The EL5462 has been designed and specified at a gain of +1
with R
gives 500MHz of -3dB bandwidth at A
peaking. With A
300MHz of bandwidth with 1dB of peaking. Since the
EL5462 is a current-feedback amplifier, it is also possible to
change the value of R
the curve of Frequency Response for Various R
bandwidth and peaking can be easily modified by varying the
value of the feedback resistor.
Because the EL5462 is a current-feedback amplifier, its
gain-bandwidth product is not a constant for different closed-
loop gains. This feature actually allows the EL5462 to
maintain about the same -3dB bandwidth. As gain is
increased, bandwidth decreases slightly while stability
increases. Since the loop stability is improving with higher
closed-loop gains, it becomes possible to reduce the value
of R
resulting in only a slight loss of bandwidth with increased
closed-loop gain.
Supply Voltage Range and Single-Supply
Operation
The EL5462 has been designed to operate with supply
voltages having a span of greater than 5V and less than 10V.
In practical terms, this means that they will operate on dual
supplies ranging from ±2.5V to ±5V. With single-supply, the
EL5462 will operate from 5V to 10V.
As supply voltages continue to decrease, it becomes
necessary to provide input and output voltage ranges that
can get as close as possible to the supply voltages. The
EL5462 has an input range which extends to within 2V of
either supply. So, for example, on +5V supplies, the EL5462
has an input range which spans ±3V. The output range of the
EL5462 is also quite large, extending to within 1V of the
supply rail. On a ±5V supply, the output is therefore capable
of swinging from -4V to +4V. Single-supply output range is
larger because of the increased negative swing due to the
external pull-down resistor to ground.
Video Performance
For good video performance, an amplifier is required to
maintain the same output impedance and the same
frequency response as DC levels are changed at the output.
This is especially difficult when driving a standard video load
of 150Ω, because of the change in output current with DC
level. Previously, good differential gain could only be
achieved by running high idle currents through the output
transistors (to reduce variations in output impedance.)
These currents were typically comparable to the entire 1mA
supply current of the EL5462 amplifier. Special circuitry has
been incorporated in the EL5462 to reduce the variation of
output impedance with current output. This results in dG and
F
below the specified TBDΩ and still retain stability,
F
approximately 606Ω. This value of feedback resistor
V
= -2, an R
F
to get more bandwidth. As seen in
F
of approximately 600Ω gives
7
V
= 1 with 0.5dB of
F
and R
G
,
EL5462
dP specifications of 0.1% and 0.1°, while driving 150Ω at a
gain of 2.
Video performance has also been measured with a 500Ω
load at a gain of +1. Under these conditions, the EL5462 has
dG and dP specifications of 0.1% and 0.1°.
Output Drive Capability
In spite of its low 1.5mA of supply current, the EL5462 is
capable of providing a minimum of ±50mA of output current.
With a minimum of ±50mA of output drive, the EL5462 is
capable of driving 50Ω loads to both rails, making it an
excellent 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 EL5462 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
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 value of the feedback
resistor (R
Current Limiting
The EL5462 has 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 EL5462, it is
possible to exceed the 125°C Absolute Maximum junction
temperature under certain very high load current conditions.
Generally speaking when R
important to calculate the maximum junction temperature
(TJ
voltages, load conditions, or package type need to be
modified for the EL5462 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
JMAX
the package
MAX
JA
MAX
MAX
= Thermal resistance of the package
=
) for the application to determine if power supply
= Maximum ambient temperature
T
F
= Maximum power dissipation of each amplifier in
MAX
) to reduce the peaking.
+
(
θ
JA
×
n
×
PD
L
falls below about 25Ω, it is
MAX
)
G
) can then be chosen to
February 14, 2005
FN7492.0