DATASHEET

EL2186, EL2286
®
Data Sheet
September 26, 2001
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 cabledriver, 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.
Ordering Information
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 150Ω
• 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
TEMP. RANGE
PACKAGE
PKG. NO.
• Cable drivers
EL2186CN
-40°C to +85°C
8-Pin PDIP
MDP0031
• RGB amplifiers
EL2186CS
-40°C to +85°C
8-Pin SOIC
MDP0027
• Test equipment amplifiers
EL2286CN
-40°C to +85°C
14-Pin PDIP
MDP0031
• Current to voltage converters
EL2286CS
-40°C to +85°C
14-Pin SOIC
MDP0027
PART NUMBER
FN7056
Pinouts
EL2286*
(14-PIN SO, PDIP)
TOP VIEW
EL2186*
(8-PIN SO, PDIP)
TOP VIEW
*Manufactured under U.S. Patent No. 5,418,495
1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 321-724-7143 | Intersil (and design) is a registered trademark of Intersil Americas Inc.
Copyright © Intersil Americas Inc. 2003. All Rights Reserved. Elantec is a registered trademark of Elantec Semiconductor, Inc.
All other trademarks mentioned are the property of their respective owners.
EL2186, EL2286
Absolute Maximum Ratings (TA = 25°C)
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
Voltage between VS+ and VS- . . . . . . . . . . . . . . . . . . . . . . . . +12.6V
Common-Mode Input Voltage . . . . . . . . . . . . . . . . . . . . . VS- to VS+
Differential Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .±6V
Current into +IN or -IN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .±7.5mA
Internal Power Dissipation . . . . . . . . . . . . . . . . . . . . . . . See Curves
Operating Ambient
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: TJ = TC = TA
DC Electrical Specifications
PARAMETER
VS = ±5V, RL = 150Ω, ENABLE = 0V, TA = 25°C unless otherwise specified
DESCRIPTION
CONDITIONS
MIN
TYP
MAX
UNIT
2.5
15
mV
VOS
Input Offset Voltage
TCVOS
Average Input Offset Voltage Drift
Measured from TMIN to TMAX
dVOS
VOS Matching
EL2286 only
+IIN
+ Input Current
d+IIN
+ IIN Matching
-IIN
- Input Current
d-IIN
-IIN Matching
EL2286 only
CMRR
Common Mode Rejection Ratio
VCM = ±3.5V
-ICMR
- Input Current Common Mode Rejection VCM = ±3.5V
PSRR
Power Supply Rejection Ratio
VS is moved from ±4V to ±6V
-IPSR
- Input Current Power Supply Rejection
VS is moved from ±4V to ±6V
ROL
Transimpedance
VOUT = ±2.5V
120
300
kΩ
+RIN
+ Input Resistance
VCM = ±3.5V
0.5
2
MΩ
+CIN
+ Input Capacitance
1.2
pF
CMIR
Common Mode Input Range
±3.5
±4.0
V
VO
Output Voltage Swing
±3.5
±4.0
V
VS = +5 Single-Supply, High
4.0
V
VS = +5 Single-Supply, Low
0.3
V
IO
5
µV/°C
0.5
mV
1.5
EL2286 only
20
16
Output Current
VS = ±5
15
45
nA
40
µA
2
µA
50
dB
5
60
µA
30
70
1
µA/V
dB
15
µA/V
EL2186 only
80
100
mA
EL2286 only, per Amplifier
50
55
mA
IOUT, OFF
Output Current Disable
VOUT ±2V, AV = [email protected]°C
IS
Supply Current
ENABLE = 2.0V, per Amplifier
IS(DIS)
Supply Current (Disabled)
COUT(DIS)
10
µA
3
6
mA
ENABLE = 4.5V
0
50
µA
Output Capacitance (Disabled)
ENABLE = 4.5V
4.4
pF
REN
Enable Pin Input Resistance
Measured at ENABLE = 2.0V, 4.5V
85
kΩ
IIH
Logic “1” Input Current
Measured at ENABLE, ENABLE = 4.5V
-0.04
µA
IIL
Logic “0” Input Current
Measured at ENABLE, ENABLE = 0V
-53
µA
VDIS
Minimum Voltage at ENABLE to Disable
VEN
Maximum Voltage at ENABLE to Enable
2
45
4.5
V
2.0
V
EL2186, EL2286
AC Electrical Specifications
PARAMETER
VS = ±5V, RF = RG = 750Ω, RL = 150Ω, ENABLE = 0V, TA = 25°C unless otherwise specified
DESCRIPTION
CONDITIONS
MIN
TYP
MAX
UNIT
-3dB BW
-3dB Bandwidth
AV = +1
250
MHz
-3dB BW
-3dB Bandwidth
AV = +2
180
MHz
0.1dB BW
0.1dB Bandwidth
AV = +2
50
MHz
SR
Slew Rate
VOUT = ±2.5V, AV = +2
1200
V/µs
tR, tF
Rise and Fall Time
VOUT = ±500mV
1.5
ns
tPD
Propagation Delay
VOUT = ±500mV
1.5
ns
OS
Overshoot
VOUT = ±500mV
3.0
%
tS
0.1% Settling
VOUT = ±2.5V, AV = -1
15
ns
dG
Differential Gain
AV = +2, RL = 150Ω (Note1)
0.05
%
dP
Differential Phase
AV = +2, RL = 150Ω (Note1)
0.05
dG
Differential Gain
AV = +1, RL = 500Ω (Note1)
0.01
%
dP
Differential Phase
AV = +1, RL = 500Ω (Note1)
0.01
°
tON
Turn-On Time
AV = +2, VIN = +1V, RL = 150Ω (Note 2)
40
100
ns
tOFF
Turn-Off Time
AV = +2, VIN = +1V, RL = 150Ω (Note 2)
1500
2000
ns
CS
Channel Separation
EL2286 only, f = 5MHz
600
85
NOTES:
1. DC offset from 0V to 0.714V, AC amplitude 286mVP-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.
3
dB
EL2186, EL2286
Test Circuit (per Amplifier)
Simplified Schematic (per Amplifier)
4
EL2186, EL2286
Typical Performance Curves
Non-Inverting Frequency
Response (Gain)
Inverting Frequency
Response (Gain)
Transimpedance (ROL)
vs Frequency
5
Non-Inverting Frequency
Response (Phase)
Inverting Frequency
Response (Phase)
PSRR and CMRR
vs Frequency
Frequency Response
for Various RF and RG
Frequency Response
for Various RL and CL
Frequency Response for
Various CIN-
EL2186, EL2286
Typical Performance Curves
(Continued)
Voltage and Current
Noise vs Frequency
-3dB Bandwidth and Peaking
vs Supply Voltage for
Various Non-Inverting Gains
Supply Current vs
Supply Voltage
6
2nd and 3rd Harmonic
Distortion vs Frequency
Output Voltage
Swing vs Frequency
-3dB Bandwidth and Peaking
vs Supply Voltage for
Various Inverting Gains
Output Voltage Swing
vs Supply Voltage
Common-Mode Input Range
vs Supply Voltage
Slew Rate vs
Supply Voltage
EL2186, EL2286
Typical Performance Curves
(Continued)
Input Bias Current
vs Die Temperature
Short-Circuit Current
vs Die Temperature
Transimpedance (ROL)
vs Die Temperature
-3dB Bandwidth and Peaking
vs Die Temperature for
Various Non-Inverting Gains
-3dB Bandwidth vs
Die Temperature for
Various Inverting Gains
Input Offset Voltage
vs Die Temperature
Supply Current vs
Die Temperature
Input Voltage Range
vs Die Temperature
Slew Rate vs
Die Temperature
7
EL2186, EL2286
Typical Performance Curves
(Continued)
Differential Gain and
Phase vs DC Input
Voltage at 3.58MHz
Small-Signal Step Response
Differential Gain and
Phase vs DC Input
Voltage at 3.58MHz
Settling Time vs
Settling Accuracy
Large-Signal Step Response
8-Pin Plastic DIP
Maximum Power Dissipation
vs Ambient Temperature
14-Pin Plastic DIP
Maximum Power Dissipation
vs Ambient Temperature
8
8-Pin SO
Maximum Power Dissipation
vs Ambient Temperature
14-Pin SO
Maximum Power Dissipation
vs Ambient Temperature
Channel Separation
vs Frequency (EL2286)
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 gainbandwidth 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
9
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 750Ω 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 RF and RG, and Frequency Response
for Various CIN-.
EL2186, EL2286
Feedback Resistor Values
The EL2186/EL2286 have been designed and specified at
gains of +1 and +2 with RF = 750Ω. This value of feedback
resistor gives 250MHz of -3dB bandwidth at AV = +1 with
about 2.5dB of peaking, and 180MHz of -3dB bandwidth at
AV = +2 with about 0.1dB of peaking. Since the
EL2186/EL2286 are current-feedback amplifiers, it is also
possible to change the value of RF to get more bandwidth.
As seen in the curve of Frequency Response For Various RF
and RG, 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 RF below
the specified 750Ω 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 150Ω, 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
10
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 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
EL2186/EL2286 have dG and dP specifications of 0.01%
and 0.01° respectively while driving 500Ω at AV = +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 50Ω 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 50Ω 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 5Ω and 50Ω) can be placed in series with the
output to eliminate most peaking. The gain resistor (RG) 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 (RF) 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 RL falls below about
25Ω, it is important to calculate the maximum junction
temperature (TJmax) 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
TJMAX = TMAX + (θJA * n * PDMAX) [1]
where:
TMAX=Maximum Ambient Temperature
θJA=Thermal Resistance of the Package
n=Number of Amplifiers in the Package
PDMAX=Maximum Power Dissipation of Each Amplifier in
the Package.
PDMAX for each amplifier can be calculated as follows:
PDMAX = (2 * VS * ISMAX) + (VS - VOUTMAX) *
(VOUTMAX/RL) [2]
where:
VS=Supply Voltage
ISMAX=Maximum Supply Current of 1 Amplifier
VOUTMAX=Max. Output Voltage of the Application
RL=Load Resistance
Typical Application Circuits
LOW POWER MULTIPLEXER WITH SINGLE-ENDED TTL INPUT
11
EL2186, EL2286
Typical Application Circuits
(Continued)
INVERTING 200mA OUTPUT CURRENT DISTRIBUTION
AMPLIFIER
FAST-SETTLING PRECISION AMPLIFIER
50
50
50
50
DIFFERENTIAL LINE-DRIVER/RECEIVER
12
EL2186, EL2286
EL2186/EL2286 Macromodel
* EL2186 Macromodel
* Revision A, March 1995
* AC characteristics used: Rf = Rg = 750 ohms
* Connections:
+input
*
|
-input
*
|
|
+Vsupply
*
|
|
|
-Vsupply
*
|
|
|
| output
*
|
|
|
| |
.subckt EL2186/e. 2 7 4 6
*
* Input Stage
*
e1 10 0 3 0 1.0
vis 10 9 0V
h2 9 12 vxx 1.0
r1 2 11 400
l1 11 12 25nH
iinp 3 0 1.5uA
iinm 2 0 3uA
r12 3 0 2Meg
*
* Slew Rate Limiting
*
h1 13 0 vis 600
r2 13 14 1K
d1 14 0 dclamp
d2 0 14 dclamp
*
* High Frequency Pole
*
e2 30 0 14 0 0.00166666666
l3 30 17 150nH
c5 17 0 0.8pF
r5 17 0 165
*
* Transimpedance Stage
*
g1 0 18 17 0 1.0
rol 18 0 450K
cdp 18 0 0.675pF
*
* Output Stage
*
q1 4 18 19 qp
q2 7 18 20 qn
q3 7 19 21 qn
q4 4 20 22 qp
r7 21 6 4
r8 22 6 4
ios1 7 19 1mA
ios2 20 4 1mA
*
* Supply Current
ips 7 4 0.2mA
*
* Error Terms
*
ivos 0 23 0.2mA
13
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
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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
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14
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