Page 1
EL2160C December 1995 Rev B
EL2160C
130 MHz Current Feedback Amplifier
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.
©
1993 Elantec, Inc.
Features
# 130 MHz 3 dB bandwidth
(A
V
ea
2)
# 180 MHz 3 dB bandwidth
(A
V
ea
1)
# 0.01% differential gain,
R
L
e
500X
# 0.01
§
differential phase,
R
L
e
500X
# Low supply current, 8.5 mA
# Wide supply range,
g
2V tog15V
# 80 mA output current (peak)
# Low cost
# 1500 V/ms slew rate
# Input common mode range to
within 1.5V of supplies
# 35 ns settling time to 0.1%
Applications
# Video amplifiers
# Cable drivers
# RGB amplifiers
# Test equipment amplifiers
# Current to voltage converter
Ordering Information
Part No. Temp. Range Package Outline
Ý
EL2160CNb40§Ctoa85§C 8-Pin P-DIP MDP0031
EL2160CSb40§Ctoa85§C 8-Pin SOIC MDP0027
General Description
The EL2160C is a current feedback operational amplifier with
b
3 dB bandwidth of 130 MHz at a gain ofa2. Built using the
Elantec proprietary monolithic complementary bipolar process,
this amplifer 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 75X coax
cable to video levels. Differential gain and phase are excellent
when driving both loads of 500X (
k
0.01%/k0.01§) and double
terminated 75X cables (0.025%/0.1
§
).
The amplifier can operate on any supply voltage from 4V
(
g
2V) to 33V (g16.5V), yet consume only 8.5 mA at any supply voltage. Using industry standard pinouts, the EL2160C is
available in 8-pin P-DIP and 8-pin SO packages. For dual and
quad applications, please see the EL2260C/EL2460C datasheet.
Elantec’s facilities comply with MIL-I-45208A and offer applicable quality specifications. See the Elantec document, QRA-2:
Elantec’s Military ProcessingÐMonolithic Products.
Connection Diagram
EL2160C SO, P-DIP
Packages
2060– 1
Top View
Page 2
EL2160C
130 MHz Current Feedback Amplifier
Absolute Maximum Ratings
(T
A
e
25§C)
Voltage between V
S
a
and V
S
b
a
33V
Voltage between
a
IN andbIN
g
6V
Current into
a
IN orbIN 10 mA
Internal Power Dissipation See Curves
Operating Ambient Temperature Range
b
40§Ctoa85§C
Operating Junction Temperature
Plastic Packages 150
§
C
Output Current
g
50 mA
Storage Temperature Range
b
65§Ctoa150§C
Important Note:
All parameters having Min/Max specifications are guaranteed. The Test Level column indicates the specific device testing actually
performed during production and Quality inspection. Elantec performs most electrical tests using modern high-speed automatic test
equipment, specifically the LTX77 Series system. Unless otherwise noted, all tests are pulsed tests, therefore T
J
e
T
C
e
TA.
Test Level Test Procedure
I 100% production tested and QA sample tested per QA test plan QCX0002.
II 100% production tested at T
A
e
25§C and QA sample tested at T
A
e
25§C,
T
MAX
and T
MIN
per QA test plan QCX0002.
III QA sample tested per QA test plan QCX0002.
IV Parameter is guaranteed (but not tested) by Design and Characterization Data.
V Parameter is typical value at T
A
e
25§C for information purposes only.
Open Loop DC Electrical Characteristics
V
S
e
g
15V, R
L
e
150X,T
A
e
25§C unless otherwise specified
Parameter Description Conditions Temp
Limits Test Level
Units
Min Typ Max EL2160C
V
OS
Input Offset Voltage V
S
e
g
5V,g15V 25§C 2 10 I mV
TC V
OS
Average Offset Voltage
Full 10 V mV/
§
C
Drift (Note 1)
a
I
IN
a
Input Current V
S
e
g
5V,g15V 25§C 0.5 5 I mA
b
I
IN
b
Input Current V
S
e
g
5V,g15V 25§C 5 25 I mA
CMRR Common Mode Rejection V
S
e
g
5V,g15V
25
§
C5055 II dB
Ratio (Note 2)
b
ICMR
b
Input Current Common V
S
e
g
5V,g15V
25
§
C 0.2 5 I mA/V
Mode Rejection (Note 2)
PSRR Power Supply Rejection
25
§
C7595 II dB
Ratio (Note 3)
b
IPSR
b
Input Current Power
25
§
C 0.2 5 I mA/V
Supply Rejection (Note 3)
2
TDis 2.5in
Page 3
EL2160C
130 MHz Current Feedback Amplifier
Open Loop DC Electrical Characteristics
Ð Contd.
V
S
e
g
15V, R
L
e
150X,T
A
e
25§C unless otherwise specified
Parameter Description Conditions Temp
Limits Test Level
Units
Min Typ Max EL2160C
R
OL
Transimpedance V
S
e
g
15V
25
§
C 500 2000 I kX
(Note 4) R
L
e
400X
V
S
e
g
5V
25
§
C 500 1800 I kX
R
L
e
150X
a
R
IN
a
Input Resistance 25§C 1.5 3.0 II MX
a
C
IN
a
Input Capacitance 25§C 2.5 V pF
CMIR Common Mode Input Range V
S
e
g
15V 25§C
g
13.5 V V
V
S
e
g
5V 25§C
g
3.5 V V
V
O
Output Voltage Swing R
L
e
400X,
25
§
C
g
12
g
13.5 I V
V
S
e
g
15V
R
L
e
150X,
25
§
C
g
12 V V
V
S
e
g
15V
R
L
e
150X,
25
§
C
g
3.0
g
3.7 I V
V
S
e
g
5V
I
SC
Output Short Circuit V
S
e
g
5V,
25
§
C 60 100 150 I mA
Current (Note 5) V
S
e
g
15V
I
S
Supply Current V
S
e
g
15V 25§C 8.5 12.0 I mA
V
S
e
g
5V 25§C 6.4 9.5 I mA
3
TDis 3.4in
Page 4
EL2160C
130 MHz Current Feedback Amplifier
Closed Loop AC Electrical Characteristics
V
S
e
g
15V, A
V
ea
2, R
F
e
560X,R
L
e
150X,T
A
e
25§C unless otherwise noted
Parameter Description Conditions
Limits Test Level
Units
Min Typ Max EL2160C
BW
b
3 dB Bandwidth V
S
e
g
15V, A
V
ea
2 130 V MHz
(Note 8)
V
S
e
g
15V, A
V
ea
1 180 V MHz
V
S
e
g
5V, A
V
ea
2 100 V MHz
V
S
e
g
5V, A
V
ea
1 110 V MHz
SR Slew Rate R
L
e
400X 1000 1500 IV V/ms
(Notes 6, 8)
R
F
e
1KX,R
G
e
110X
1500 V V/m s
R
L
e
400X
tr,t
f
Rise Time, V
OUT
e
g
500mV
2.7 V ns
Fall Time, (Note 8)
t
pd
Propagation Delay
3.2 V ns
(Note 8)
OS Overshoot (Note 8) V
OUT
e
g
500 mV 0 V %
t
s
0.1% Settling Time V
OUT
e
g
10V
35 V ns
(Note 8) A
V
eb
1, R
L
e
1K
dG Differential Gain R
L
e
150X 0.025 V %
(Notes 7, 8)
R
L
e
500X 0.006 V %
dP Differential Phase R
L
e
150X 0.1 V deg (§)
(Notes 7, 8) R
L
e
500X 0.005 V deg (§)
Note 1: Measured from T
MIN
to T
MAX
.
Note 2: V
CM
e
g
10V for V
S
e
g
15V and T
A
e
25§C
V
CM
e
g
3V for V
S
e
g
5V and T
A
e
25§C
Note 3: The supplies are moved from
g
2.5V tog15V.
Note 4: V
OUT
e
g
7V for V
S
e
g
15V, and V
OUT
e
g
2V for V
S
e
g
5V.
Note 5: A heat sink is required to keep junction temperature below absolute maximum when an output is shorted.
Note 6: Slew Rate is with V
OUT
froma10V tob10V and measured at the 25% and 75% points.
Note 7: DC offset from
b
0.714V througha0.714V, AC amplitude 286 mV
p-p
,fe3.58 MHz.
Note 8: All AC tests are performed on a ‘‘warmed up’’ part, except for Slew Rate, which is pulse tested.
4
TDis 3.5in
Page 5
EL2160C
130 MHz Current Feedback Amplifier
Typical Performance Curves
Response (Gain)
Non-Inverting Frequency
Response (Phase)
Non-Inverting Frequency
for Various R
L
Frequency Response
Response (Gain)
Inverting Frequency
Response (Phase)
Inverting Frequency
Various R
F
and R
G
Frequency Response for
Voltage for A
V
eb
1
3 dB Bandwidth vs Supply
for A
V
eb
1
Peaking vs Supply Voltage
Temperature for A
V
eb
1
3 dB Bandwidth vs
2060– 2
5
Page 6
EL2160C
130 MHz Current Feedback Amplifier
Typical Performance Curves
Ð Contd.
Voltage for A
V
ea
1
3 dB Bandwidth vs Supply
for A
V
ea
1
Peaking vs Supply Voltage
for A
V
ea
1
3 dB Bandwidth vs Temperature
Voltage for A
V
ea
2
3 dB Bandwidth vs Supply
for A
V
ea
2
Peaking vs Supply Voltage
for A
V
ea
2
3 dB Bandwidth vs Temperature
Voltage for A
V
ea
10
3 dB Bandwidth vs Supply
for A
V
ea
10
Peaking vs Supply Voltage
for A
V
ea
10
3 dB Bandwidth vs Temperature
2060– 3
6
Page 7
EL2160C
130 MHz Current Feedback Amplifier
Typical Performance Curves
Ð Contd.
for Various C
L
Frequency Response
for Various C
IN
b
Frequency Response
vs Frequency
PSRR and CMRR
Distortion vs Frequency
2nd and 3rd Harmonic
vs Frequency
Transimpedance (R
OL
)
vs Frequency
Voltage and Current Noise
Impedance vs Frequency
Closed-Loop Output
vs Die Temperature
Transimpedance (R
OL
)
2060– 4
7
Page 8
EL2160C
130 MHz Current Feedback Amplifier
Typical Performance Curves
Ð Contd.
(4 Samples)
vs Die Temperature
Offset Voltage
vs Die Temperature
Supply Current
vs Supply Voltage
Supply Current
vs Die Temperature
a
Input Resistance
vs Die Temperature
Input Current
vs Input Voltage
a
Input Bias Current
vs Die Temperature
Output Voltage Swing
vs Die Temperature
Short Circuit Current
vs Die Temperature
PSRR & CMRR
2060– 5
8
Page 9
EL2160C
130 MHz Current Feedback Amplifier
Typical Performance Curves
Ð Contd.
R
L
e
150
vs DC Input Voltage,
Differential Gain
R
L
e
150
vs DC Input Voltage,
Differential Phase
Pulse Response
Small Signal
R
L
e
500
vs DC Input Voltage,
Differential Gain
R
L
e
500
vs DC Input Voltage,
Differential Phase
Pulse Response
Large Signal
vs Supply Voltage
Slew Rate
vs Temperature
Slew Rate
vs Settling Accuracy
Settling Time
2060– 6
9
Page 10
EL2160C
130 MHz Current Feedback Amplifier
Typical Performance Curves
Ð Contd.
Long Term Settling Error vs Ambient Temperature
Maximum Power Dissipation
8-Lead Plastic DIP
vs Ambient Temperature
Maximum Power Dissipation
8-Lead Plastic SO
2060– 7
Burn-In Circuit
EL2160C
2060– 8
10
Page 11
EL2160C
130 MHz Current Feedback Amplifier
Differential Gain and Phase Test Circuit
2060– 9
Simplified Schematic
(One Amplifier)
2060– 10
11
Page 12
EL2160C
130 MHz Current Feedback Amplifier
Applications Information
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
3 dB bandwidth is dependent on the value of the
feedback resistor. First the desired bandwidth is
selected by choosing the feedback resistor, R
F
,
and then the gain is set by picking the gain resistor, R
G
. The curves at the beginning of the Typical Performance Curves section show the effect of
varying both R
F
and RG. The 3 dB 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 (/4
×
. The power supply pins
must be well bypassed to reduce the risk of oscillation. A 1.0 mF tantalum capacitor in parallel
with a 0.01 mF 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 wire-wound 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 noninverting configuration. The characteristic curve
of gain vs. frequency with variations of C
IN
b
emphasizes this effect. The curve illustrates how
the bandwidth can be extended to beyond
200 MHz with some additional peaking with an
additional 2 pF of capacitance at the V
IN
b
pin
for the case of A
V
ea
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
F
e
560X for A
V
ea
2. This value of
feedback resistor yields extremely flat frequency
response with little to no peaking out to
130 MHz. 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
F
to
430X, bandwidth can be extended to 170 MHz
with under 1 dB of peaking. Further reduction of
R
F
to 360X increases the bandwidth to 195 MHz
with about 2.5 dB of peaking. See the curves in
the Typical Performance Curves section which
show 3 dB bandwidth and peaking vs. frequency
for various feedback resistors and various supply
voltages.
Bandwidth vs Temperature
Whereas many amplifier’s supply current and
consequently 3 dB 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 3 dB
bandwidth does not drop off drastically with
temperature. With V
S
e
g
15V and A
V
ea
2,
the bandwidth only varies from 150 MHz to
110 MHz over the entire die junction temperature range of 0
§
CkTk150§C.
12
Page 13
EL2160C
130 MHz Current Feedback Amplifier
Applications Information
Ð Contd.
Supply Voltage Range
The EL2160C has been designed to operate with
supply voltages from
g
2V tog15V. Optimum
bandwidth, slew rate, and video characteristics
are obtained at higher supply voltages. However,
at
g
2V supplies, the 3 dB bandwidth at A
V
e
a
2 is a respectable 70 MHz. The following figure
is an oscilloscope plot of the EL2160C at
g
2V
supplies, A
V
ea
2, R
F
e
R
G
e
560X, driving a
load of 150X, showing a clean
g
600 mV signal at
the output.
2060– 11
If a single supply is desired, values froma4V to
a
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 35 ns to 40 ns 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
g
10V gives approximately the same settling
time.
As can be seen from the Long Term Settling Error curve, for A
V
ea
1, there is approximately a
0.035% residual which tails away to 0.01% in
about 40 ms. This is a thermal settling error
caused by a power dissipation differential (before
and after the voltage step). For A
V
eb
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 noninverting mode. With A
V
eb
1, 0.01% settling
time is slightly greater than 100 ns.
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
P
DMAX
e
T
JMAX
b
T
AMAX
i
JA
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
e
2 * VS* I
S
a
(V
S
b
V
OUT
)*
V
OUT
R
L
where ISis 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
13
Page 14
EL2160C
130 MHz Current Feedback Amplifier
Applications Information
Ð Contd.
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.
The EL2160C consumes typically 8.5 mA and
maximum 11.0 mA. 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
DMAX
equations equal to each other, and solve
for V
S
, we can get a family of curves for various
loads and output voltages according to:
V
S
e
RL* (T
JMAX
b
T
AMAX
)
i
JA
a
(V
OUT
)
2
(2 * IS* RL)aV
OUT
The following curves show supply voltage (gVS)
vs R
LOAD
for various output voltage swings for
the 2 different packages. The curves assume
worst case conditions of T
A
ea
85§C and I
S
e
11 mA.
Various V
OUT
(SO Package)
Supply Voltage vs R
LOAD
for
2060– 12
Supply Voltage vs R
LOAD
for
Various V
OUT
(PDIP Package)
2060– 13
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 100 mA
nominally and reduces with junction temperature. At a junction temperature of 150
§
C, the current limits at about 65 mA. 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 (5X –50X) resistor in series with the
output will eliminate most peaking. The gain resistor, R
G
, can be chosen to make up for the gain
loss created by this additional series resistor at
the output.
14
Page 15
EL2160C
130 MHz Current Feedback Amplifier
EL2160C Macromodel
* Revision A, November 1993
* AC Characteristics used C
IN
b
(pin 2)e1 pF; R
F
e
560X
* Connections:
a
input
*
l
b
input
*
ll
a
Vsupply
*
lll
b
Vsupply
*
llll
output
*
lllll
.subckt EL2160C/EL 3 2 7 4 6
*
* Input Stage
*
e1100301.0
vis 10 9 0V
h2 9 12 vxx 1.0
r1211130
l1 11 12 25nH
iinp 3 0 0.5m A
iinm205mA
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 0.43m H
c5 17 0 0.27pF
r5 17 0 500
*
* Transimpedance Stage
*
g10181701.0
ro1 18 0 2Meg
cdp 18 0 2.285pF
*
* Output Stage
*
q141819qp
q271820qn
q371921qn
q442022qp
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
e4240301.0
e5250701.0
e6260401.0
r9 24 23 562
r10 25 23 1K
r11 26 23 1K
*
* Models
*
.model qn npn (is
e5eb
15 bfe100 tfe0.1ns)
.model qp pnp (is
e5eb
15 bfe100 tfe0.1ns)
.model dclamp d (is
e1eb
30 ibve0.266 bve2.24 ne4)
.ends
15
TABWIDE
TDis 6.5in TDis 2.6in
Page 16
EL2160CDecember 1995 Rev B
EL2160C
130 MHz Current Feedback Amplifier
EL2160C Macromodel
Ð Contd.
2060– 14
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.
Elantec, Inc.
1996 Tarob Court
Milpitas, CA 95035
Telephone: (408) 945-1323
(800) 333-6314
Fax: (408) 945-9305
European Office: 44-71-482-4596
WARNING Ð 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 support 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.
Printed in U.S.A.16
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