Page 1
EL2160C
180MHz Current Feedback Amplifier
EL2160C
Features
• 130MHz 3dB bandwidth (AV=+2)
• 180MHz 3dB bandwidth (AV=+1)
• 0.01% differential gain, R
• 0.01° differential phase, R
=500Ω
L
=500Ω
L
• Low supply current, 8.5mA
• Wide supply range, ±2V to ±15V
• 80mA output current (peak)
• Low cost
• 1500V/µs slew rate
• Input common mode range to
within 1.5V of supplies
• 35ns settling time to 0.1%
Applications
• Video amplifiers
• Cable drivers
• RGB amplifiers
• Test equipment amplifiers
• Current to voltage converters
Ordering Information
Part No. Package Tape & Reel Outline#
EL2160CN 8-Pin PDIP - MDP0031
EL2160CS-T7 8-Pin SO 7” MDP0027
EL2160CS-T13 8-Pin SO 13” MDP0027
EL2160CM 16-Pin SO (0.300”) - MDP0027
EL2160CM-T13 16-Pin SO (0.300”) 13” MDP0027
General Description
The EL2160C is a current feedback operational amplifier with -3dB
bandwidth of 130MHz at a gain of +2. Built using the Elantec proprietary monolithic complementary bipolar process, this amplifier uses
current mode feedback to achieve more bandwidth at a given gain than
a conventional voltage feedback operational amplifier.
The EL2160C is designed to drive a double terminated 75Ω coax
cable to video levels. Differential gain and phase are excellent when
driving both loads of 500Ω (<0.01%/<0.01°) and double terminated
75Ω cables (0.025%/0.1°).
The amplifier can operate on any supply voltage from 4V (±2V) to
33V (±16.5V), yet consume only 8.5mA at any supply voltage. Using
industry-standard pinouts, the EL2160C is available in 8-pin PDIP and
SO packages, as well as a 16-pin SO (0.300”) package. All are specified for operation over the full -40°C to +85°C temperature range. For
dual and quad applications, please see the EL2260C/EL2460C
datasheet.
Connection Diagrams
+IN
1
NC
2
NC
3
-IN
-
4
NC
+
5
16
NC
15
NC
14
VS+
13
NC
12
OUT
1
NC
8
NC
+IN
VS-
2
-IN
-
+
3
4
8-Pin PDIP/SO16-Pin SO (0.300”)
6
NC
7
VS-
8 9
NC
Note: All information contained in this data sheet has been carefully checked and is believed to be accurate as of the date of publication; however, this data sheet cannot be a “controlled document”. Current revisions, if any, to these
specifications are maintained at the factory and are available upon your request. We recommend checking the revision level before finalization of your design documentation.
© 2001 Elantec Semiconductor, Inc.
11
NC
10
NC
NC
7
VS+
6
OUT
5
NC
September 26, 2001
Page 2
EL2160C
180MHz Current Feedback Amplifier
EL2160C
Absolute Maximum Ratings (T
Voltage between VS+ and VS- +33V
Voltage between +IN and -IN ±6V
Current into +IN or -IN 10mA
Internal Power Dissipation See Curves
= 25°C)
A
Operating Junction Temperature
Plastic Packages 150°C
Output Current ±50mA
Storage Temperature Range -65°C to +150°C
Operating Ambient Temperature Range -40°C to +85°C
Important Note:
All parameters having Min/Max specifications are guaranteed. Typ values are for information purposes only. Unless otherwise noted, all tests are at the
specified temperature and are pulsed tests, therefore: TJ = TC = TA.
Open Loop DC Electrical Characteristics
VS = ±15V, R
Parameter Description Conditions Temp
V
OS
TC V
+I
IN
-I
IN
CMRR Common Mode Rejection Ratio
-ICMR -Input Current Common Mode Rejection
PSRR Power Supply Rejection Ratio
-IPSR -Input Current Power Supply Rejection
R
OL
+R
+C
CMIR Common Mode Input Range VS = ±15V 25°C ±13.5 V
V
O
I
SC
I
S
1. Measured from T
2. VCM = ±10V for VS = ±15V and TA = 25°C, VCM = ±3V for VS = ±5V and TA = 25°C
3. The supplies are moved from ±2.5V to ±15V
4. V
5. A heat sink is required to keep junction temperature below absolute maximum when an output is shorted
= 150Ω, T
L
Input Offset Voltage VS = ±5V, ±15V 25°C 2 10 mV
OS
Average Offset Voltage Drift
+Input Current VS = ±5V, ±15V 25°C 0.5 5 µA
-Input Current VS = ±5V, ±15V 25°C 5 25 µA
Transimpedance
IN
IN
+Input Resistance 25°C 1.5 3.0 MΩ
+Input Capacitance 25°C 2.5 pF
Output Voltage Swing R
Output Short Circuit Current
Supply Current VS = ±15V 25°C 8.5 12.0 mA
= ±7V for VS = ±15V, and V
OUT
= 25°C unless otherwise specified.
A
[1]
[2]
[3]
[4]
[5]
to T
MIN
MAX
= ±2V for VS = ±5V
OUT
Limits
UnitMin Typ Max
Full 10 µV/°C
[2]
[3]
VS = ±5V, ±15V 25°C 50 55 dB
VS = ±5V, ±15V 25°C 0.2 5 µA/V
25°C 75 95 dB
25°C 0.2 5 µA/V
VS = ±15V
R
= 400Ω
L
VS = ±5V
R
= 150Ω
L
25°C 500 2000 kΩ
25°C 500 1800 kΩ
VS = ±5V 25°C ±3.5 V
= 400Ω
L
25°C ±12 ±13.5 V
VS =±15V
R
= 150Ω
L
25°C ±12 V
VS =±15V
R
= 150Ω
L
25°C ±3.0 ±3.7 V
VS =±5V
VS = ±5V, 25°C 60 100 150 mA
VS = ±15V
VS = ±5V 25°C 6.4 9.5 mA
2
Page 3
Closed Loop AC Electrical Characteristics
VS = ±15V, AV = +2, R
Parameter Description Conditions
BW -3dB Bandwidth
SR Slew Rate
tr, t
f
t
pd
OS Overshoot
t
s
dG Differential Gain
dP Differential Phase
1. All AC tests are performed on a “warmed up” part, except for Slew Rate, which is pulse tested
2. Slew Rate is with V
3. DC offset from -0.714V through +0.714V, AC amplitude 286mV
= 560Ω, RL = 150Ω, T
F
[1]
[2] [1]
Rise Time, Fall Time
Propagation Delay
[1]
0.1% Settling Time
[3] [1]
[3] [1]
from +10V to -10V and measured at the 25% and 75% points
OUT
= 25°C unless otherwise noted.
A
VS = ±15V, AV = +2 130 MHz
VS = ±15V, AV = +1 180 MHz
VS = ±5V, AV = +2 100 MHz
VS = ±5V, AV = +1 110 MHz
R
= 400Ω 1000 1500 V/µs
L
R
= 1KΩ, RG = 110Ω
F
R
= 400Ω
[1]
[1]
[1]
L
V
= ±500mV 2.7 ns
OUT
V
= ±500mV 0 %
OUT
V
= ±10V
OUT
AV = -1, RL = 1k
R
= 150Ω 0.025 %
L
R
= 500Ω 0.006 %
L
R
= 150Ω 0.1 °
L
R
= 500Ω 0.005 °
L
, f = 3.58MHz
p-p
EL2160C
EL2160C
180MHz Current Feedback Amplifier
Limits
UnitMin Typ Max
1500 V/µs
3.2 ns
35 ns
3
Page 4
EL2160C
180MHz Current Feedback Amplifier
EL2160C
Typical Performance Curves
Non-Inverting Frequency
Response (Gain)
Inverting Frequency
Response (Gain)
Non-Inverting Frequency
Response (Phase)
Inverting Frequency
Response (Phase)
Frequency Response
for Various R
Frequency Response for
Various RF and R
L
G
R
F
3dB Bandwidth vs Supply
Voltage for AV = -1
Peaking vs Supply Voltage
for AV = -1
4
3dB Bandwidth vs
Temperature for AV = - 1
Page 5
EL2160C
180MHz Current Feedback Amplifier
EL2160C
3dB Bandwidth vs Supply
Voltage for AV = +1
3dB Bandwidth vs Supply
Voltage for AV = +2
Peaking vs Supply Voltage
for AV = +1
Peaking vs Supply Voltage
for AV = +2
3dB Bandwidth vs Temperature
for AV = +1
3dB Bandwidth vs Temperature
for AV = +2
3dB Bandwidth vs Supply
Voltage for AV = +10
Peaking vs Supply Voltage
for AV = +10
5
3dB Bandwidth vs Temperature
for AV = +10
Page 6
EL2160C
180MHz Current Feedback Amplifier
EL2160C
Frequency Response
for Various C
2nd and 3rd Harmonic
Distortion vs Frequency
L
Frequency Response
for Various C
Transimpedance (ROL)
vs Frequency
IN-
PSRR and CMRR
vs Frequency
Voltage and Current Noise
vs Frequency
Closed-Loop Output
Impedance vs Frequency
Transimpedance (ROL)
vs Die Temperature
6
Page 7
EL2160C
180MHz Current Feedback Amplifier
EL2160C
Offset Voltage
vs Die Temperature
(4 Samples)
+Input Resistance
vs Die Temperature
Supply Current
vs Die Temperature
Input Current
vs Die Temperature
Supply Current
vs Supply Voltage
+Input Bias Current
vs Input Voltage
Output Voltage Swing
vs Die Temperature
Short Circuit Current
vs Die Temperature
PSRR & CMRR
vs Die Temperature
7
Page 8
EL2160C
180MHz Current Feedback Amplifier
EL2160C
Differential Gain
vs DC Input Voltage,
RL = 150
Differential Gain
vs DC Input Voltage,
RL = 500
Differential Phase
vs DC Input Voltage,
RL = 150
Differential Phase
vs DC Input Voltage,
RL = 500
Small Signal
Pulse Response
Large Signal
Pulse Response
Slew Rate
vs Supply Voltage
Slew Rate
vs Temperature
Settling Time
vs Settling Accuracy
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Page 9
EL2160C
180MHz Current Feedback Amplifier
EL2160C
Long Term Settling Error
Burn-In Circuit
Package Power Dissipation vs Ambient Temp.
JEDEC JESD51-3 Low Effective Thermal Conductivity Test Board
1.6
1.344
1.4
1.2
1.250
1
0.8
781m
0.6
Power Dissipation (W)
0.4
0.2
0
0 25 50 75 100 125 15085
SO16 (0.300”)
θJA=93°C/W
SO8
θJA=160°C/W
Ambient Temperature (°C)
PDIP8
θJA=100°C/W
EL2160C
9
Page 10
EL2160C
180MHz Current Feedback Amplifier
EL2160C
Differential Gain and Phase Test Circuit
Simplified Schematic (One Amplifier)
10
Page 11
Applications Information
EL2160C
EL2160C
180MHz Current Feedback Amplifier
Product Description
The EL2160C is a current mode feedback amplifier that
offers wide bandwidth and good video specifications at a
moderately low supply current. It is built using Elantec's
proprietary complimentary bipolar process and is
offered in industry standard pin-outs. Due to the current
feedback architecture, the EL2160C closed-loop 3dB
bandwidth is dependent on the value of the feedback
resistor. First the desired bandwidth is selected by
choosing the feedback resistor, RF, and then the gain is
set by picking the gain resistor, RG. The curves at the
beginning of the Typical Performance Curves section
show the effect of varying both RF and RG. The 3dB
bandwidth is somewhat dependent on the power supply
voltage. As the supply voltage is decreased, internal
junction capacitances increase, causing a reduction in
closed loop bandwidth. To compensate for this, smaller
values of feedback resistor can be used at lower supply
voltages.
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, below ¼.
The power supply pins must be well bypassed to reduce
the risk of oscillation. A 1.0µF tantalum capacitor in
parallel with a 0.01µF ceramic capacitor is adequate for
each supply pin.
For good AC performance, parasitic capacitances should
be kept to a minimum, especially at the inverting input
(see Capacitance at the Inverting Input section). This
implies keeping the ground plane away from this pin.
Carbon resistors are acceptable, while use of wirewound resistors should not be used because of their parasitic inductance. Similarly, capacitors should be low
inductance for best performance. Use of sockets, particularly for the SO package, should be avoided. Sockets
add parasitic inductance and capacitance which will
result in peaking and overshoot.
Capacitance at the Inverting Input
Due to the topology of the current feedback amplifier,
stray capacitance at the inverting input will affect the
AC and transient performance of the EL2160C when
operating in the non-inverting configuration. The characteristic curve of gain vs. frequency with variations of
CIN- emphasizes this effect. The curve illustrates how
the bandwidth can be extended to beyond 200MHz with
some additional peaking with an additional 2pF of
capacitance at the VIN- pin for the case of AV = +2.
Higher values of capacitance will be required to obtain
similar effects at higher gains.
In the inverting gain mode, added capacitance at the
inverting input has little effect since this point is at a virtual ground and stray capacitance is therefore not “seen”
by the amplifier.
Feedback Resistor Values
The EL2160C has been designed and specified with
R
=560Ω for A
F
yields extremely flat frequency response with little to no
peaking out to 130MHz. As is the case with all current
feedback amplifiers, wider bandwidth, at the expense of
slight peaking, can be obtained by reducing the value of
the feedback resistor. Inversely, larger values of feedback resistor will cause rolloff to occur at a lower
frequency. By reducing R
extended to 170MHz with under 1dB of peaking. Further reduction of R
195MHz with about 2.5dB of peaking. See the curves in
the Typical Performance Curves section which show
3dB bandwidth and peaking vs. frequency for various
feedback resistors and various supply voltages.
= +2. This value of feedback resistor
V
to 430Ω, bandwidth can be
F
to 360Ω increases the bandwidth to
F
Bandwidth vs Temperature
Whereas many amplifier's supply current and consequently 3dB bandwidth drop off at high temperature, the
EL2160C was designed to have little supply current
variations with temperature. An immediate benefit from
this is that the 3dB bandwidth does not drop off drastically with temperature. With VS = ±15V and AV = +2,
the bandwidth only varies from 150MHz to 110MHz
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Page 12
EL2160C
180MHz Current Feedback Amplifier
EL2160C
over the entire die junction temperature range of 0°C < T
< 150°C.
Supply Voltage Range
The EL2160C has been designed to operate with supply
voltages from ±2V to ±15V. Optimum bandwidth, slew
rate, and video characteristics are obtained at higher supply voltages. However, at ±2V supplies, the 3dB
bandwidth at AV = +2 is a respectable 70MHz. The following figure is an oscilloscope plot of the EL2160C at
±2V supplies, AV = +2, RF = R
= 560Ω, driving a load
G
of 150Ω, showing a clean ±600mV signal at the output.
If a single supply is desired, values from +4V to +30V
can be used as long as the input common mode range is
not exceeded. When using a single supply, be sure to
either 1) DC bias the inputs at an appropriate common
mode voltage and AC couple the signal, or 2) ensure the
driving signal is within the common mode range of the
EL2160C.
Settling Characteristics
The EL2160C offers superb settling characteristics to
0.1%, typically in the 35ns to 40ns range. There are no
aberrations created from the input stage which often
cause longer settling times in other current feedback
amplifiers. The EL2160C is not slew rate limited, therefore any size step up to ±10V gives approximately the
same settling time.
As can be seen from the Long Term Settling Error curve,
for AV = +1, there is approximately a 0.035% residual
which tails away to 0.01% in about 40µs. This is a thermal settling error caused by a power dissipation
differential (before and after the voltage step). For AV =
-1, due to the inverting mode configuration, this tail does
not appear since the input stage does not experience the
large voltage change as in the non-inverting mode. With
AV = -1, 0.01% settling time is slightly greater than
100ns.
Power Dissipation
The EL2160C amplifier combines both high speed and
large output current drive capability at a moderate supply current in very small packages. It is possible to
exceed the maximum junction temperature allowed
under certain supply voltage, temperature, and loading
conditions. To ensure that the EL2160C remains within
its absolute maximum ratings, the following discussion
will help to avoid exceeding the maximum junction
temperature.
The maximum power dissipation allowed in a package is
determined by its thermal resistance and the amount of
temperature rise according to:
T
–
JMAXTAMAX
DMAX
2V
---------------------------------------------
=
θ
JA
SV(SVOUT
V
OUT
)
---------------×–+×=
R
L
P
The maximum power dissipation actually produced by
an IC is the total quiescent supply current times the total
power supply voltage plus the power in the IC due to the
load, or:
P
DMAX
where IS is the supply current. (To be more accurate, the
quiescent supply current flowing in the output driver
transistor should be subtracted from the first term
because, under loading and due to the class AB nature of
the output stage, the output driver current is now
included in the second term.)
In general, an amplifier's AC performance degrades at
higher operating temperature and lower supply current.
Unlike some amplifiers, the EL2160C maintains almost
constant supply current over temperature so that AC performance is not degraded as much over the entire
operating temperature range. Of course, this increase in
performance doesn't come for free. Since the current has
increased, supply voltages must be limited so that maximum power ratings are not exceeded.
12
Page 13
EL2160C
180MHz Current Feedback Amplifier
EL2160C
The EL2160C consumes typically 8.5mA and maximum
11.0mA. The worst case power in an IC occurs when the
output voltage is at half supply, if it can go that far, or its
maximum values if it cannot reach half supply. If we set
the two P
equations equal to each other, and solve
DMAX
for VS, we can get a family of curves for various loads
and output voltages according to:
RLT
()×
MAX-TAMAX
----------------------------------------------------------
V
S
θ
JA
V
()2( I
OUT
SRL
) V
+××[]÷+=
OUT
The following curves show supply voltage (±VS) vs
R
for various output voltage swings for the 2 dif-
LOAD
ferent packages. The curves assume worst case
conditions of TA = +85°C and IS = 11mA.
Supply Voltage vs R
(8-Pin SO Package)
Supply Voltage vs R
Various V
OUT
for Various V
LOAD
for
LOAD
(PDIP Package)
OUT
The curves do not include heat removal or forcing air, or
the simple fact that the package will probably 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.
Current Limit
The EL2160C has an internal current limit that protects
the circuit in the event of the output being shorted to
ground. This limit is set at 100mA nominally and
reduces with junction temperature. At a junction temperature of 150°C, the current limits at about 65mA. If the
output is shorted to ground, the power dissipation could
be well over 1W. Heat removal is required in order for
the EL2160C to survive an indefinite short.
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 EL2160C from the capacitive cable
and allow extensive capacitive drive. However, other
applications may have high capacitive loads without termination resistors. In these applications, an additional
small value (5Ω–50Ω) resistor in series with the output
will eliminate most peaking. The gain resistor, RG, can
be chosen to make up for the gain loss created by this
additional series resistor at the output.
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Page 14
EL2160C
180MHz Current Feedback Amplifier
EL2160C
EL2160C Macromodel
* Revision A, November 1993
* AC Characteristics used CIN- (pin 2) = 1 pF; R
* Connections: +input
* | -input
* | | +Vsupply
* | | | -Vsupply
* | | | | output
* | | | | |
.subckt EL2160C/EL 3 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 11 130
l1 11 12 25nH
iinp 3 0 0.5µA
iinm 2 0 5µA
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 0.43µH
c5 17 0 0.27pF
r5 17 0 500
*
* Transimpedance Stage
*
g1 0 18 17 0 1.0
ro1 18 0 2Meg
cdp 18 0 2.285pF
*
* 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 2mA
ios2 20 4 2mA
*
* Supply Current
*
ips 7 4 3mA
*
* Error Terms
*
ivos 0 23 2mA
vxx 23 0 0V
e4 24 0 3 0 1.0
e5 25 0 7 0 1.0
= 560Ω
F
14
Page 15
e6 26 0 4 0 1.0
r9 24 23 562
r10 25 23 1K
r11 26 23 1K
*
* Models
*
.model qn npn (is=5e-15 bf=100 tf=0.1ns)
.model qp pnp (is=5e-15 bf=100 tf=0.1ns)
.model dclamp d (is=1e-30 ibv=0.266 bv=2.24 n=4)
.ends
EL2160C Macromodel
EL2160C
EL2160C
180MHz Current Feedback Amplifier
15
Page 16
EL2160C
180MHz Current Feedback Amplifier
EL2160C
16
Page 17
EL2160C
180MHz Current Feedback Amplifier
EL2160C
17
Page 18
EL2160C
180MHz Current Feedback Amplifier
EL2160C
General Disclaimer
Specifications contained in this data sheet are in effect as of the publication date shown. Elantec, Inc. reserves the right to make changes in the circuitry or specifications contained herein at any time without notice. Elantec, Inc. assumes no responsibility for the use of any circuits described
herein and makes no representations that they are free from patent infringement.
WARNING - Life Support Policy
Elantec, Inc. products are not authorized for and should not be used
within Life Support Systems without the specific written consent of
Elantec, Inc. Life Support systems are equipment intended to sup-
Elantec Semiconductor, Inc.
675 Trade Zone Blvd.
Milpitas, CA 95035
Telephone: (408) 945-1323
(888) ELANTEC
Fax: (408) 945-9305
European Office: +44-118-977-6020
Japan Technical Center: +81-45-682-5820
port or sustain life and whose failure to perform when properly used
in accordance with instructions provided can be reasonably
expected to result in significant personal injury or death. Users contemplating application of Elantec, Inc. Products in Life Support
Systems are requested to contact Elantec, Inc. factory headquarters
to establish suitable terms & conditions for these applications. Elantec, Inc.’s warranty is limited to replacement of defective
components and does not cover injury to persons or property or
other consequential damages.
September 26, 2001
18
Printed in U.S.A.
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