FN7056

CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.

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EL2186, EL2286

250MHz/3mA Current Mode Feedback
Amp w/Disable

The EL2186/EL2286 are single/dual
current-feedback operational
amplifiers which achieve a -3dB

bandwidth of 250MHz at a gain of +1 while consuming only
3mA of supply current per amplifier. They will operate with
dual supplies ranging from ±1.5V to ±6V, or from single
supplies ranging from +3V to +12V. The EL2186/EL2286
also include a disable/power-down feature which reduces
current consumption to 0mA while placing the amplifier
output in a high impedance state. In spite of its low supply
current, the EL2286 can output 55mA while swinging to ±4V
on ±5V supplies. The EL2186 can output 100mA with similar
output swings. These attributes make the EL2186/EL2286
excellent choices for low power and/or low voltage cable-
driver, HDSL, or RGB applications.

For Single, Dual and Quad applications without disable,
consider the EL2180 (8-Pin Single), EL2280 (8-Pin Dual) or
EL2480 (14-Pin Quad). For lower power applications where
speed is still a concern, consider the EL2170/EL2176 family
which also comes in similar Single, Dual and Quad
configurations. The EL2170/EL2176 family provides a -3dB
bandwidth of 70MHz while consuming 1mA of supply current
per amplifier.

Features

· Single (EL2186) and dual (EL2286) topologies

· 3mA supply current (per amplifier)

· 250MHz -3dB bandwidth

· Low cost

· Fast disable

· Powers down to 0mA

· Single- and dual-supply operation down to ±1.5V

· 0.05%/0.05° diff. gain/diff. phase into 150

· 1200V/µs slew rate

· Large output drive current:

-100mA (EL2186)
-55mA (EL2286)

· Also available without disable in single (EL2180), dual

(EL2280) and quad (EL2480)

· Lower power EL2170/EL2176 family also available

(1mA/70MHz) in single, dual and quad

Applications

· Low power/battery applications

· HDSL amplifiers

· Video amplifiers

· Cable drivers

· RGB amplifiers

· Test equipment amplifiers

· Current to voltage converters

Ordering Information

PART NUMBER

TEMP. RANGE

PACKAGE

PKG. NO.

EL2186CN

-40°C to +85°C

8-Pin PDIP

MDP0031

EL2186CS

-40°C to +85°C

8-Pin SOIC

MDP0027

EL2286CN

-40°C to +85°C

14-Pin PDIP

MDP0031

EL2286CS

-40°C to +85°C

14-Pin SOIC

MDP0027

Pinouts

EL2186*

(8-PIN SO, PDIP)

TOP VIEW

EL2286*

(14-PIN SO, PDIP)

TOP VIEW

*Manufactured under U.S. Patent No. 5,418,495

Data Sheet

September 26, 2001

Absolute Maximum Ratings

= 25°C)

Voltage between V

+ and V

- . . . . . . . . . . . . . . . . . . . . . . . . +12.6V

Common-Mode Input Voltage . . . . . . . . . . . . . . . . . . . . . V

- to V

Differential Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .±6V
Current into +IN or -IN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .±7.5mA
Internal Power Dissipation . . . . . . . . . . . . . . . . . . . . . . . See Curves
Operating Ambient

Temperature Range . . . . . . . . . . . . . . . . . . . . . . . . . . -40°C to +85°C
Operating Junction Temperature
Plastic Packages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150°C
Output Current (EL2186) . . . . . . . . . . . . . . . . . . . . . . . . . . . ±120mA
Output Current (EL2286) . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±60mA
Storage Temperature Range . . . . . . . . . . . . . . . . . . -65°C to +150°C

CAUTION: Stresses above those listed in "Absolute Maximum Ratings" may cause permanent damage to the device. This is a stress only rating and operation of the
device at these or any other conditions above those indicated in the operational sections of this specification is not implied.

IMPORTANT NOTE: All parameters having Min/Max specifications are guaranteed. Typical values are for information purposes only. Unless otherwise noted, all tests
are at the specified temperature and are pulsed tests, therefore: T

= T

DC Electrical Specifications

= ±5V, R

= 150

, ENABLE = 0V, T

= 25°C unless otherwise specified

PARAMETER

DESCRIPTION

CONDITIONS

MIN

TYP

MAX

UNIT

Input Offset Voltage

2.5

TCV

Average Input Offset Voltage Drift

Measured from T

MIN

to T

MAX

µV/°C

Matching

EL2286 only

0.5

+ Input Current

1.5

µA

d+I

+ I

Matching

EL2286 only

-I

- Input Current

µA

d-I

-I

Matching

EL2286 only

µA

CMRR

Common Mode Rejection Ratio

= ±3.5V

-ICMR

- Input Current Common Mode Rejection V

= ±3.5V

µA/V

PSRR

Power Supply Rejection Ratio

is moved from ±4V to ±6V

-IPSR

- Input Current Power Supply Rejection

is moved from ±4V to ±6V

µA/V

Transimpedance

OUT

= ±2.5V

120

300

+ Input Resistance

= ±3.5V

0.5

+ Input Capacitance

1.2

CMIR

Common Mode Input Range

±3.5

±4.0

Output Voltage Swing

= ±5

±3.5

±4.0

= +5 Single-Supply, High

4.0

= +5 Single-Supply, Low

0.3

Output Current

EL2186 only

100

EL2286 only, per Amplifier

OUT, OFF

Output Current Disable

OUT

±2V, A

= +1@25°C

µA

Supply Current

ENABLE = 2.0V, per Amplifier

S(DIS)

Supply Current (Disabled)

ENABLE = 4.5V

µA

OUT(DIS)

Output Capacitance (Disabled)

ENABLE = 4.5V

4.4

Enable Pin Input Resistance

Measured at ENABLE = 2.0V, 4.5V

Logic "1" Input Current

Measured at ENABLE, ENABLE = 4.5V

-0.04

µA

Logic "0" Input Current

Measured at ENABLE, ENABLE = 0V

-53

µA

DIS

Minimum Voltage at ENABLE to Disable

4.5

Maximum Voltage at ENABLE to Enable

2.0

EL2186, EL2286

AC Electrical Specifications

= ±5V, R

= R

= 750

, R

= 150

, ENABLE = 0V, T

= 25°C unless otherwise specified

PARAMETER

DESCRIPTION

CONDITIONS

MIN

TYP

MAX

UNIT

-3dB BW

-3dB Bandwidth

= +1

250

MHz

-3dB BW

-3dB Bandwidth

= +2

180

MHz

0.1dB BW

0.1dB Bandwidth

= +2

MHz

Slew Rate

OUT

= ±2.5V, A

= +2

600

1200

V/µs

, t

Rise and Fall Time

OUT

= ±500mV

1.5

Propagation Delay

OUT

= ±500mV

1.5

Overshoot

OUT

= ±500mV

3.0

0.1% Settling

OUT

= ±2.5V, A

= -1

Differential Gain

= +2, R

= 150

(Note1)

0.05

Differential Phase

= +2, R

= 150

(Note1)

0.05

Differential Gain

= +1, R

= 500

(Note1)

0.01

Differential Phase

= +1, R

= 500

(Note1)

0.01

Turn-On Time

= +2, V

= +1V, R

= 150

(Note 2)

100

OFF

Turn-Off Time

= +2, V

= +1V, R

= 150

(Note 2)

1500

2000

Channel Separation

EL2286 only, f = 5MHz

NOTES:

1. DC offset from 0V to 0.714V, AC amplitude 286mV

P-P

, f = 3.58MHz.

2. Measured from the application of the logic signal until the output voltage is at the 50% point between initial and final values.

EL2186, EL2286

Applications Information

Product Description

The EL2186/EL2286 are current-feedback operational
amplifiers that offer a wide -3dB bandwidth of 250MHz, a low
supply current of 3mA per amplifier and the ability to disable
to 0mA. Both products also feature high output current drive.
The EL2186 can output 100mA, while the EL2286 can
output 55mA per amplifier. The EL2186/EL2286 work with
supply voltages ranging from a single 3V to ±6V, and they
are also capable of swinging to within 1V of either supply on
the input and the output. Because of their current-feedback
topology, the EL2186/EL2286 do not have the normal gain-
bandwidth product associated with voltage-feedback
operational amplifiers. This allows their -3dB bandwidth to
remain relatively constant as closed-loop gain is increased.
This combination of high bandwidth and low power, together
with aggressive pricing make the EL2186/EL2286 the ideal
choice for many low-power/high-bandwidth applications such
as portable computing, HDSL, and video processing.

For Single, Dual and Quad applications without disable,
consider the EL2180 (8-Pin Single), EL2280 (8-Pin Dual)
and EL2480 (14-Pin Quad). If lower power is required, refer
to the EL2170/EL2176 family which provides Singles, Duals,
and Quads with 70MHz of bandwidth while consuming 1mA
of supply current per amplifier.

Power Supply Bypassing and Printed Circuit
Board Layout

As with any high-frequency device, good printed circuit
board layout is necessary for optimum performance. Ground
plane construction is highly recommended. Lead lengths
should be as short as possible. The power supply pins must
be well bypassed to reduce the risk of oscillation. The
combination of a 4.7µF tantalum capacitor in parallel with a
0.1µF capacitor has been shown to work well when placed at
each supply pin.

For good AC performance, parasitic capacitance should be
kept to a minimum especially at the inverting input (see the
Capacitance at the Inverting Input section). Ground plane
construction should be used, but it should be removed from
the area near the inverting input to minimize any stray
capacitance at that node. Carbon or Metal-Film resistors are
acceptable with the Metal-Film resistors giving slightly less
peaking and bandwidth because of their additional series
inductance. Use of sockets, particularly for the SO package
should be avoided if possible. Sockets add parasitic
inductance and capacitance which will result in some
additional peaking and overshoot.

Disable/Power-Down

The EL2186/EL2286 amplifiers can be disabled, placing
their output in a high-impedance state. When disabled, each
amplifier's supply current is reduced to 0mA. Each
EL2186/EL2286 amplifier is disabled when its ENABLE pin

is floating or pulled up to within 0.5V of the positive supply.
Similarly, each amplifier is enabled by pulling its ENABLE pin
at least 3V below the positive supply. For ±5V supplies, this
means that an EL2186/EL2286 amplifier will be enabled
when ENABLE is at 2V or less, and disabled when ENABLE
is above 4.5V. Although the logic levels are not standard
TTL, this choice of logic voltages allows the EL2186/EL2286
to be enabled by tying ENABLE to ground, even in +3V
single-supply applications. The ENABLE pin can be driven
from CMOS outputs or open-collector TTL.

When enabled, supply current does vary somewhat with the
voltage applied at ENABLE. For example, with the supply
voltages of the EL2186 at ±5V, if ENABLE is tied to -5V
(rather than ground) the supply current will increase about
15% to 3.45mA.

Capacitance at the Inverting Input

Any manufacturer's high-speed voltage- or current-feedback
amplifier can be affected by stray capacitance at the
inverting input. For inverting gains this parasitic capacitance
has little effect because the inverting input is a virtual
ground, but for non-inverting gains this capacitance (in
conjunction with the feedback and gain resistors) creates a
pole in the feedback path of the amplifier. This pole, if low
enough in frequency, has the same destabilizing effect as a
zero in the forward open-loop response. The use of large
value feedback and gain resistors further exacerbates the
problem by further lowering the pole frequency.

The EL2186/EL2286 have been specially designed to
reduce power dissipation in the feedback network by using
large 750

feedback and gain resistors. With the high

bandwidths of these amplifiers, these large resistor values
would normally cause stability problems when combined
with parasitic capacitance, but by internally canceling the
effects of a nominal amount of parasitic capacitance, the
EL2186/EL2286 remain very stable. For less experienced
users, this feature makes the EL2186/EL2286 much more
forgiving, and therefore easier to use than other products not
incorporating this proprietary circuitry.

The experienced user with a large amount of PC board
layout experience may find in rare cases that the
EL2186/EL2286 have less bandwidth than expected. In this
case, the inverting input may have less parasitic capacitance
than expected by the internal compensation circuitry of the
EL2186/EL2286. The reduction of feedback resistor values
(or the addition of a very small amount of external
capacitance at the inverting input, e.g. 0.5pF) will increase
bandwidth as desired. Please see the curves for Frequency
Response for Various R

and R

, and Frequency Response

for Various C

EL2186, EL2286

Feedback Resistor Values

The EL2186/EL2286 have been designed and specified at
gains of +1 and +2 with R

= 750

. This value of feedback

resistor gives 250MHz of -3dB bandwidth at A

= +1 with

about 2.5dB of peaking, and 180MHz of -3dB bandwidth at
A

= +2 with about 0.1dB of peaking. Since the

EL2186/EL2286 are current-feedback amplifiers, it is also
possible to change the value of R

to get more bandwidth.

As seen in the curve of Frequency Response For Various R

and R

, bandwidth and peaking can be easily modified by

varying the value of the feedback resistor.

Because the EL2186/EL2286 are current-feedback
amplifiers, their gain-bandwidth product is not a constant for
different closed-loop gains. This feature actually allows the
EL2186/EL2286 to maintain about the same -3dB
bandwidth, regardless of closed-loop gain. However, as
closed-loop 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

below

the specified 750

and still retain stability, resulting in only a

slight loss of bandwidth with increased closed-loop gain.

Supply Voltage Range and Single-Supply
Operation

The EL2186/EL2286 have been designed to operate with
supply voltages having a span of greater than 3V, and less
than 12V. In practical terms, this means that the
EL2186/EL2286 will operate on dual supplies ranging from
±1.5V to ±6V. With a single-supply, the EL2176 will operate
from +3V to +12V.

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
EL2186/EL2286 have an input voltage range that extends to
within 1V of either supply. So, for example, on a single +5V
supply, the EL2186/EL2286 have an input range which
spans from 1V to 4V. The output range of the
EL2186/EL2286 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 even larger because of the increased negative
swing due to the external pull-down resistor to ground. On a
single +5V supply, output voltage range is about 0.3V to 4V.

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 150

, because of the change in output current with DC

level. Until the EL2186/EL2286, 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 3mA

supply current of each EL2186/EL2286 amplifier! Special
circuitry has been incorporated in the EL2186/EL2286 to
reduce the variation of output impedance with current output.
This results in dG and dP specifications of 0.05% and 0.05°
while driving 150

at a gain of +2.

Video Performance has also been measured with a 500

load at a gain of +1. Under these conditions, the
EL2186/EL2286 have dG and dP specifications of 0.01%
and 0.01° respectively while driving 500

at A

= +1.

Output Drive Capability

In spite of its low 3mA of supply current, the EL2186 is
capable of providing a minimum of ±80mA of output current.
Similarly, each amplifier of the EL2286 is capable of
providing a minimum of ±50mA. These output drive levels
are unprecedented in amplifiers running at these supply
currents. With a minimum ±80mA of output drive, the
EL2186 is capable of driving 50

loads to ±4V, making it an

excellent choice for driving isolation transformers in
telecommunications applications. Similarly, the ±50mA
minimum output drive of each EL2286 amplifier allows
swings of ±2.5V into 50

loads.

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 EL2186/EL2286 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 5

and 50

) can be placed in series with the

output to eliminate most peaking. The gain resistor (R

) can

then be chosen to 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

) to reduce the peaking.

Current Limiting

The EL2186/EL2286 have no internal current-limiting
circuitry. If any output is shorted, it is possible to exceed the
Absolute Maximum Ratings for output current or power
dissipation, potentially resulting in the destruction of the
device.

Power Dissipation

With the high output drive capability of the EL2186/EL2286,
it is possible to exceed the 150°C Absolute Maximum
junction temperature under certain very high load current
conditions. Generally speaking, when R

falls below about

, it is important to calculate the maximum junction

temperature (T

Jmax

) for the application to determine if

power-supply voltages, load conditions, or package type
need to be modified for the EL2186/EL2286 to remain in the
safe operating area. These parameters are calculated as
follows:

EL2186, EL2286

vxx 23 0 0V
e4 24 0 3 0 1.0
e5 25 0 7 0 1.0
e6 26 0 4 0 -1.0
r9 24 23 316
r10 25 23 3.2K
r11 26 23 3.2K
*
* Models
*
.model qn npn(is=5e-15 bf=200 tf=0.01nS)
*.model qp pnp(is=5e-15 bf=200 tf=0.01nS)
.model dclamp d(is=1e-30 ibv=0.266
+ bv=0.71v n=4)
.ends

EL2186/EL2286 Macromodel

EL2186, EL2286

All Intersil U.S. products are manufactured, assembled and tested utilizing ISO9000 quality systems.

Intersil Corporation's quality certifications can be viewed at www.intersil.com/design/quality

Intersil products are sold by description only. Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time without
notice. Accordingly, the reader is cautioned to verify that data sheets are current before placing orders. Information furnished by Intersil is believed to be accurate and
reliable. However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result
from its use. No license is granted by implication or otherwise under any patent or patent rights of Intersil or its subsidiaries.

For information regarding Intersil Corporation and its products, see www.intersil.com

Ð­Ð»ÐµÐºÑ‚Ñ€Ð¾Ð½Ð½Ñ‹Ð¹ ÐºÐ¾Ð¼Ð¿Ð¾Ð½ÐµÐ½Ñ‚: EL2286CS

ÐÐ»ÐµÐºÑ‚Ñ€Ð¾Ð½Ð½Ñ‹Ð¹ ÐºÐ¾Ð¼Ð¿Ð¾Ð½ÐµÐ½Ñ‚: EL2286CS