EL5191ACS [INTERSIL]
1GHz Current Feedback Amplifier with Enable; 1GHz的电流反馈放大器启用型号: | EL5191ACS |
厂家: | Intersil |
描述: | 1GHz Current Feedback Amplifier with Enable |
文件: | 总17页 (文件大小:409K) |
中文: | 中文翻译 | 下载: | 下载PDF数据表文档文件 |
EL5191, EL5191A
®
ata Sheet
Augus t 3, 2005
FN7180.2
1GHz Current Feedback Amplifier with
Enable
Features
• 1GHz -3dB bandwidth
• 9mA supply current
The EL5191 and EL5191A amplifiers are of the current
feedback variety and exhibit a very high bandwidth of 1GHz.
This makes these amplifiers ideal for today’s high speed
video and monitor applications, as well as a number of RF
and IF frequency designs.
• Single and dual supply operation, from 5V to 10V supply
span
• Fast enable/disable (EL5191A only)
• Available in SOT-23 packages
With a supply current of just 9mA and the ability to run from
a single supply voltage from 5V to 10V, these amplifiers offer
very high performance for little power consumption.
• High speed, 600MHz product available (EL5192, EL5292,
and EL5392)
The EL5191A also incorporates an enable and disable
function to reduce the supply current to 100µA typical per
amplifier. Allowing the CE pin to float or applying a low logic
level will enable the amplifier.
• Lower power, 300MHz product available (EL5193,
EL5293, EL5393)
• Pb-Free plus anneal available (RoHS compliant)
The EL5191 is offered in the 5-pin SOT-23 package and the
EL5191A is available in the 6-pin SOT-23 as well as the
industry-standard 8-pin SO packages. Both operate over the
industrial temperature range of -40°C to +85°C.
Applications
• Video amplifiers
• Cable drivers
• RGB amplifiers
Ordering Information
TAPE &
REEL
• Test equipment
• Instrumentation
• Current to voltage converters
PART NUMBER
PACKAGE
PKG. DWG. #
MDP0027
EL5191CS
8-Pin SO
-
-
EL5191CSZ
(See Note)
8-Pin SO
(Pb-free)
MDP0027
Pinouts
EL5191CSZ-T7
(See Note)
8-Pin SO
(Pb-free)
7”
MDP0027
MDP0027
EL5191CSZ-T13
(See Note)
8-Pin SO
(Pb-free)
13”
EL5191A
(8-PIN SO)
TOP VIEW
EL5191CW-T7
5-Pin SOT-23
7”
7”
MDP0038
MDP0038
EL5191CWZ-T7
(See Note)
5-Pin SOT-23
(Pb-free)
NC
IN-
1
2
3
4
8
7
6
5
CE
EL5191ACW-T7
EL5191ACW-T7A
6-Pin SOT-23 7” (3K pcs)
6-Pin SOT-23 7” (250 pcs)
MDP0038
MDP0038
MDP0038
V
+
S
-
+
EL5191ACWZ-T7
(See Note)
6-Pin SOT-23 7” (3K pcs)
(Pb-free)
IN+
OUT
NC
V
-
S
EL5191ACWZ-T7A 6-Pin SOT-23 7” (250 pcs)
MDP0038
(See Note)
(Pb-free)
8-Pin SO
8-Pin SO
8-Pin SO
EL5191ACS
-
7”
13”
-
MDP0027
MDP0027
MDP0027
MDP0027
EL5191
(5-PIN SOT-23)
TOP VIEW
EL5191A
(6-PIN SOT-23)
TOP VIEW
EL5191ACS-T7
EL5191ACS-T13
EL5191ACSZ
(See Note)
8-Pin SO
(Pb-free)
OUT
1
6
5
4
VS+
CE
OUT
1
5
4
V +
S
V
-
2
3
V
-
2
3
S
EL5191ACSZ-T7
(See Note)
8-Pin SO
(Pb-free)
7”
MDP0027
MDP0027
S
+
-
+
-
IN+
IN-
IN+
IN-
EL5191ACSZ-T13
(See Note)
8-Pin SO
(Pb-free)
13”
NOTE: Intersil Pb-free plus anneal products employ special Pb-free material sets;
molding compounds/die attach materials and 100% matte tin plate termination finish,
which are RoHS compliant and compatible with both SnPb and Pb-free soldering
operations. Intersil Pb-free products are MSL classified at Pb-free peak reflow
temperatures that meet or exceed the Pb-free requirements of IPC/JEDEC J STD-020.
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 1-888-468-3774 | Intersil (and design) is a registered trademark of Intersil Americas Inc.
Copyright Intersil Americas Inc. 2004, 2005. All Rights Reserved
1
All other trademarks mentioned are the property of their respective owners.
EL5191, EL5191A
Absolute Maximum Ratings (T = 25°C)
A
Supply Voltage between V + and V -. . . . . . . . . . . . . . . . . . . . .11V
Pin Voltages. . . . . . . . . . . . . . . . . . . . . . . . . V - -0.5V to V + +0.5V
S S
S
S
Maximum Continuous Output Current . . . . . . . . . . . . . . . . . . . 50mA
Operating Junction Temperature . . . . . . . . . . . . . . . . . . . . . . .125°C
Power Dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . See Curves
Storage Temperature. . . . . . . . . . . . . . . . . . . . . . . .-65°C to +150°C
Ambient Operating Temperature . . . . . . . . . . . . . . . .-40°C to +85°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 = T
A
J
C
Electrical Specifications V + = +5V, V - = -5V, R = 392Ω for A = 1, R = 250Ω for A = 2, R = 150Ω, T = 25°C unless otherwise
S
S
F
V
F
V
L
A
specified.
PARAMETER
AC PERFORMANCE
BW
DESCRIPTION
CONDITIONS
MIN
TYP
MAX
UNIT
-3dB Bandwidth
A
A
= +1
= +2
1000
600
30
MHz
MHz
MHz
V/µs
ns
V
V
BW1
SR
0.1dB Bandwidth
Slew Rate
V
V
= -2.5V to +2.5V, A = +2
2400
2800
7
O
V
t
0.1% Settling Time
= -2.5V to +2.5V, A = -1
OUT V
S
e
Input Voltage Noise
3.8
nV/√Hz
pA/√Hz
pA/√Hz
%
N
i -
IN- Input Current Noise
IN+ Input Current Noise
Differential Gain Error (Note 1)
Differential Phase Error (Note 1)
25
N
i +
N
55
dG
A
A
= +2
0.035
0.04
V
V
dP
= +2
°
DC PERFORMANCE
V
Offset Voltage
-15
1
5
15
mV
OS
T V
Input Offset Voltage Temperature
Coefficient
Measured from T
to T
MAX
µV/°C
C
OS
MIN
R
Transimpedance
150
300
kΩ
OL
INPUT CHARACTERISTICS
CMIR
Common Mode Input Range
Common Mode Rejection Ratio
±3
42
±3.3
50
V
dB
CMRR
-ICMR
- Input Current Common Mode Rejection
+ Input Current
-6
6
µA/V
µA
+I
-120
-60
40
5
120
60
IN
-I
- Input Current
µA
IN
R
Input Resistance
27
0.5
kΩ
pF
IN
IN
C
Input Capacitance
OUTPUT CHARACTERISTICS
V
Output Voltage Swing
R = 150Ω to GND
±3.4
±3.8
95
±3.7
±4.0
120
V
V
O
L
R = 1kΩ to GND
L
I
Output Current
R = 10Ω to GND
mA
OUT
L
SUPPLY
I
I
Supply Current - Enabled
Supply Current - Disabled
No load, V = 0V
IN
8
9
11
mA
µA
SON
No load, V = 0V
IN
100
150
SOFF
2
EL5191, EL5191A
Electrical Specifications V + = +5V, V - = -5V, R = 392Ω for A = 1, R = 250Ω for A = 2, R = 150Ω, T = 25°C unless otherwise
S
S
F
V
F
V
L
A
specified. (Continued)
PARAMETER
PSRR
-IPSR
ENABLE (EL5191A ONLY)
DESCRIPTION
CONDITIONS
MIN
55
TYP
MAX
UNIT
dB
Power Supply Rejection Ratio
DC, V = ±4.75V to ±5.25V
75
S
- Input Current Power Supply Rejection DC, V = ±4.75V to ±5.25V
-2
2
µA/V
S
t
t
I
I
Enable Time
40
600
0.8
0
ns
ns
µA
µA
V
EN
Disable Time
DIS
CE Pin Input High Current
CE Pin Input Low Current
CE Input High Voltage for Power-down
CE Input Low Voltage for Power-down
CE = V +
6
IHCE
ILCE
S
CE = V -
S
-0.1
V
V
V + - 1
S
IHCE
ILCE
V + - 3
V
S
NOTE:
1. Standard NTSC test, AC signal amplitude = 286mV
, f = 3.58MHz
P-P
3
EL5191, EL5191A
Typical Performance Curves
Non-Inverting Frequency Response (Gain)
SOT-23 Package
Non-Inverting Frequency Response (Phase)
6
2
90
0
A
= 1
A = 2
V
V
A
= 1
V
A
= 2
V
-2
-90
A
= 5
V
A
= 5
V
-6
-180
-270
-360
A
=10
V
A
= 10
V
-10
-14
R
R
= 390Ω
= 150Ω
F
L
R
R
= 390Ω
= 150Ω
F
L
1M
10M
100M
Frequency (Hz)
1G
1M
10M
100M
Frequency (Hz)
1G
Inverting Frequency Response (Gain)
SOT-23 Package
Inverting Frequency Response (Phase)
6
2
90
0
A
=-1
V
A
= -1
V
-2
-90
A
A
=-2
=-5
A = -2
V
V
A
= -5
V
-6
-180
-270
-360
V
-10
R
R
= 250Ω
= 150Ω
F
L
R
R
= 250Ω
= 150Ω
F
L
-14
1M
10M
100M
Frequency (Hz)
1G
1M
10M
100M
1G
Frequency (Hz)
Frequency Response for Various C
-
Frequency Response for Various R
L
IN
10
6
6
2
2pF added
1pF added
R
= 100Ω
= 500Ω
L
R
= 150Ω
L
R
2
-2
L
-2
-6
-10
-6
0pF added
-10
-14
A
R
R
= 2
= 250Ω
= 150Ω
V
F
L
A
R
= 2
= 250Ω
V
F
1M
10M
100M
1G
1M
10M
100M
1G
Frequency (Hz)
Frequency (Hz)
4
EL5191, EL5191A
Typical Performance Curves (Continued)
Frequency Response for Various C
Frequency Response for Various R
L
F
14
10
6
6
2
150Ω
250Ω
6pF added
4pF added
-2
375Ω
2
-6
500Ω
-2
-6
-10
-14
A
R
= 2
= 250Ω
0pF added
A
R
R
= 2
= R
= 150Ω
V
F
V
G
L
F
R =150Ω
L
1M
10M
100M
1G
1M
10M
100M
Frequency (Hz)
1G
Frequency (Hz)
Group Delay vs Frequency
Frequency Response for Various Common-Mode
Input Voltages
3.5
3
6
2
V
= 3V
V
= 0V
CM
CM
2.5
2
-2
A
= 2
A = 1
V
F
V
V
= -3V
CM
R
= 250Ω
R
= 390Ω
F
1.5
1
-6
-10
A
R
R
= 2
= 250Ω
= 150Ω
V
F
L
0.5
0
-14
1M
10M
100M
1G
1M
10M
100M
Frequency (Hz)
1G
Frequency (Hz)
Transimpedance (ROL) vs Frequency
PSRR and CMRR vs Frequency
10M
1M
20
0
0
Phase
PSRR+
-90
100k
10k
1k
-20
-40
-60
-80
PSRR-
-180
-270
-360
Gain
CMRR
10M
100
1k
10k
100k
1M
10M
100M
1G
10k
100k
1M
100M
1G
Frequency (Hz)
Frequency (Hz)
5
EL5191, EL5191A
Typical Performance Curves (Continued)
-3dB Bandwidth vs Supply Voltage for Non-
Inverting Gains
-3dB Bandwidth vs Supply Voltage for Inverting
Gains
1200
1000
800
600
400
200
0
600
500
400
300
200
100
0
R
R
= 390Ω
= 150Ω
F
L
A
= -2
V
A
= 1
A
A
= -1
= -5
V
V
V
A
A
= 2
= 5
V
V
A
9
= 10
V
R
R
= 250Ω
= 150Ω
F
L
5
6
7
8
10
5
6
7
8
9
10
Total Supply Voltage (V)
Total Supply Voltage (V)
Peaking vs Supply Voltage for Non-Inverting Gains
Peaking vs Supply Voltage for Inverting Gains
4
3.5
3
4
R
= 390Ω
F
R =150Ω
L
A
= 1
3
2
1
0
V
A
A
= -1
= -2
V
2.5
2
V
1.5
1
A
A
= 2
V
R
R
= 250Ω
= 150Ω
A
= -5
F
L
V
0.5
0
= 10
8
V
5
6
7
9
10
5
6
7
8
9
10
Total Supply Voltage (V)
Total Supply Voltage (V)
Non-Inverting Frequency Response (Gain)
SO8 Package
Non-Inverting Frequency Response (Phase)
SO8 Package
6
2
90
0
A
= 1
A = 2
V
V
A
= 1
A = 2
V
V
-2
-90
A
= 5
V
-6
-180
-270
-360
A
= 5
V
A
= 10
V
A
= 10
-10
V
R
R
= 392Ω
= 150Ω
R = 392Ω
F
F
L
R= 150Ω
L
-14
1M
10M
100M
1G 1.6G
1M
10M
100M
Frequency (Hz)
1G
Frequency (Hz)
6
EL5191, EL5191A
Typical Performance Curves (Continued)
Inverting Frequency Response (Gain)
SO8 Package
Inverting Frequency Response (Phase)
SO8 Package
6
2
90
0
A
= -1
A = -2
V
V
A
= -1
A = -2
V
V
-2
-90
A
= -5
V
A
= -5
V
-6
-180
-270
-360
-10
-14
R
R
= 250Ω
= 150Ω
R
R
= 250Ω
= 150Ω
F
L
F
L
1M
10M
100M
1G
1M
10M
100M
1G
Frequency (Hz)
Frequency (Hz)
-3dB Bandwidth vs Temperature for Non-Inverting
Gains
-3dB Bandwidth vs Temperature for Inverting
Gains
2000
1500
1000
500
0
700
600
500
400
300
200
100
0
R
R
= 250Ω
= 150Ω
F
L
A
= -1
V
A
A
=1
=5
V
A
A
= -2
= -5
V
A
=2
V
V
A
=10
V
V
R =250Ω
F
R =150Ω
L
-40
10
60
110
160
-40
10
60
110
160
Ambient Temperature (°C)
Ambient Temperature (°C)
Peaking vs Temperature
Voltage and Current Noise vs Frequency
3
2.5
2
1k
100
10
R
= 150Ω
L
A
= 1
V
i
+
N
i
-
N
1.5
1
A
= -1
V
e
N
0.5
0
A
= -2
110
V
1
100
-40
10
60
160
1k
10k
100k
1M
10M
Ambient Temperature (°C)
Frequency (Hz)
7
EL5191, EL5191A
Typical Performance Curves (Continued)
Closed Loop Output Impedance vs Frequency
Supply Current vs Supply Voltage
100
10
10
8
1
6
0.1
4
0.01
2
0.001
0
100
1k
10k 100k
1M
10M 100M
1G
200
1
0
2
4
6
8
10
12
200
1
Frequency (Hz)
Supply Voltage (V)
2nd and 3rd Harmonic Distortion vs Frequency
Two-Tone 3rd Order
Input Referred Intermodulation Intercept (IIP3)
-10
-20
-30
-40
-50
-60
-70
-80
-90
-100
30
25
20
15
10
5
A
V
= +2
V
= 2V
= 100Ω
OUT
P-P
R
L
2nd Order
Distortion
0
3rd Order
Distortion
-5
A
R
= +2
= 100Ω
-10
-15
V
L
1
10
Frequency (MHz)
100
10
100
Frequency (MHz)
Differential Gain/Phase vs DC Input
Voltage at 3.58MHz
Differential Gain/Phase vs DC Input
Voltage at 3.58MHz
0.03
0.01
0.03
0.02
0.01
0
A
R
R
= 2
A
R
R
= 1
= 375Ω
= 500Ω
V
F
L
V
F
L
dP
dG
= R = 250Ω
= 150Ω
G
dP
dG
-0.01
-0.03
-0.05
-0.01
-0.02
-0.03
-0.04
-1
-0.5
0
0.5
-1
-0.5
0
0.5
DC Input Voltage
DC Input Voltage
8
EL5191, EL5191A
Typical Performance Curves (Continued)
Output Voltage Swing vs Frequency
THD < 1%
Output Voltage Swing vs Frequency
THD < 0.1%
10
8
10
8
R
= 500Ω
= 150Ω
R
= 500Ω
= 150Ω
L
L
R
R
L
L
6
6
4
4
2
2
A
= 2
A = 2
V
V
0
0
1
10
Frequency (MHz)
100 200
1
10
100
Frequency (MHz)
Small Signal Step Response
Large Signal Step Response
V
= ±5V
= 150Ω
= 2
S
V
= ±5V
= 150Ω
= 2
S
R
A
R
L
V
F
R
A
R
L
V
F
= R = 250Ω
G
= R = 250Ω
G
200mV/div
1V/div
10ns/div
10ns/div
Transimpedance (ROI) Vs Temperature
Settling Time vs Settling Accuracy
375
350
325
300
275
250
225
200
25
20
15
10
5
A
R
= 2
V
F
= R = 250Ω
G
R = 150Ω
L
V
= 5V
output
P-P
STEP
0
-40
10
60
110
160
0.01
0.1
Settling Accuracy (%)
1
Die Temperature (°C)
9
EL5191, EL5191A
Typical Performance Curves (Continued)
PSRR and CMRR vs Temperature
ICMR and IPSR vs Temperature
ICMR+
90
70
50
30
10
2.5
2
PSRR
CMRR
1.5
1
IPSR
0.5
0
ICMR-
-0.5
-1
-40
10
60
Die Temperature (°C)
110
160
160
160
-40
10
60
110
110
110
160
160
160
Die Temperature (°C)
Offset Voltage vs Temperature
Input Current vs Temperature
2
1
140
120
100
80
60
IB+
IB-
40
0
20
0
-1
-40
-20
-40
10
60
110
10
60
Die Temperature (°C)
Temperature (°C)
Positive Input Resistance vs Temperature
Supply Current vs Temperature
35
30
25
20
15
10
5
10
9
0
-40
8
-40
10
60
110
10
60
Temperature (°C)
Temperature (°C)
10
EL5191, EL5191A
Typical Performance Curves (Continued)
Positive Output Swing vs Temperature for Various
Loads
Negative Output Swing vs Temperature for Various
Loads
4.2
4.1
4
-3.5
-3.6
-3.7
-3.8
-3.9
-4
150Ω
1kΩ
3.9
3.8
3.7
3.6
3.5
1kΩ
150Ω
-4.1
-4.2
-40
10
60
110
160
-40
10
60
110
160
Temperature (°C)
Temperature (°C)
Output Current vs Temperature
Slew Rate vs Temperature
140
135
130
125
120
115
5000
4500
4000
3500
3000
A
R
R
= 2
V
F
L
= R = 250Ω
= 150Ω
G
Sink
Source
-40
10
60
110
160
-40
10
60
Die Temperature (°C)
110
160
Die Temperature (°C)
Enable Response
Disable Response
500mV/div
5V/div
500mV/div
5V/div
20ns/div
400ns/div
Typical Performance Curves (Continued)
11
EL5191, EL5191A
JEDEC JESD51-7 HIGH EFFECTIVE
JEDEC JESD51-7 HIGH EFFECTIVE
THERMAL CONDUCTIVITY TEST BOARD
THERMAL CONDUCTIVITY TEST BOARD
1.4
1.2
1
0.5
0.45
0.4
0.35
0.3
0.25
0.2
0.15
0.1
435mW
909mW
SO8
SOT23-5/6
0.8
0.6
0.4
0.2
0
θ
=230°C/W
JA
θ
=110°C/W
JA
0.05
0
0
25
50
75 85 100
125
150
0
25
50
75 85 100
125
150
AMBIENT TEMPERATURE (°C)
AMBIENT TEMPERATURE (°C)
JEDEC JESD51-3 LOW EFFECTIVE
JEDEC JESD51-3 LOW EFFECTIVE
THERMAL CONDUCTIVITY TEST BOARD
391mW
THERMAL CONDUCTIVITY TEST BOARD
0.45
0.4
1
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
0.35
0.3
0.25
0.2
0.15
0.1
0.05
0
625mW
SO8
θ
=160°C/W
JA
0
25
50
75 85 100
125
150
0
25
50
75 85 100
125
150
AMBIENT TEMPERATURE (°C)
AMBIENT TEMPERATURE (°C)
12
EL5191, EL5191A
Pin Des criptions
8-PIN SO
5-PIN SOT-23 6-PIN SOT-23 PIN NAME
FUNCTION
Not connected
EQUIVALENT CIRCUIT
1, 5
2
NC
IN-
4
4
Inverting input
V
+
S
IN+
IN-
V
-
S
Circuit 1
(See circuit 1)
3
4
6
3
2
1
3
2
1
IN+
Non-inverting input
Negative supply
Output
V -
S
OUT
V
+
S
OUT
V
-
S
+
-
Circuit 2
7
8
5
6
5
V +
S
Positive supply
Chip enable
CE
V
S
CE
V
S
Circuit 3
13
EL5191, EL5191A
enabled when CE is 2V or less, and disabled when CE is
Applications Information
above 4V. Although the logic levels are not standard TTL,
this choice of logic voltages allows the EL5191A to be
enabled by tying CE to ground, even in 5V single supply
applications. The CE pin can be driven from CMOS outputs.
Product Des cription
The EL5191 is a current-feedback operational amplifier that
offers a wide -3dB bandwidth of 1GHz and a low supply
current of 9mA per amplifier. The EL5191 works with supply
voltages ranging from a single 5V to 10V and they are also
capable of swinging to within 1V of either supply on the
output. Because of their current-feedback topology, the
EL5191 does not have the normal gain-bandwidth product
associated with voltage-feedback operational amplifiers.
Instead, its -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 EL5191 the ideal choice for many low-power/high-
bandwidth applications such as portable, handheld, or
battery-powered equipment.
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 exacerbates the problem
by further lowering the pole frequency (increasing the
possibility of oscillation.)
For varying bandwidth needs, consider the EL5192 with
600MHz on a 6mA supply current or the EL5193 with
300MHz on a 4mA supply current. Versions include single,
dual, and triple amp packages with 5-pin SOT-23, 16-pin
QSOP, and 8-pin or 16-pin SO outlines.
The EL5191 has been optimized with a 250Ω feedback
resistor. With the high bandwidth of these amplifiers, these
resistor values might cause stability problems when
combined with parasitic capacitance, thus ground plane is
not recommended around the inverting input pin of the
amplifier.
Power Supply Bypas s ing and Printed Circuit
Board Layout
As with any high frequency device, good printed circuit
board layout is necessary for optimum performance. Low
impedance ground plane construction is essential. Surface
mount components are recommended, but if leaded
components are used, 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 0.01µF capacitor has
been shown to work well when placed at each supply pin.
Feedback Res is tor Values
The EL5191 has been designed and specified at a gain of +2
with R approximately 250Ω. This value of feedback resistor
F
gives 600MHz of -3dB bandwidth at A = 2 with about 2dB of
V
peaking. With A = -2, that same R gives 450MHz of
V
F
bandwidth with 0.6dB of peaking. Since the EL5191 is a
current-feedback amplifier, it is also possible to change the
value of R to get more bandwidth. As seen in the curve of
F
Frequency Response for Various R and R , bandwidth and
F
G
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) Even when
ground plane construction is used, 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 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 additional
peaking and overshoot.
peaking can be easily modified by varying the value of the
feedback resistor.
Because the EL5191 is a current-feedback amplifier, its
gain-bandwidth product is not a constant for different closed-
loop gains. This feature actually allows the EL5191 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 below the specified 250Ω and still retain stability,
F
resulting in only a slight loss of bandwidth with increased
closed-loop gain.
Dis able/Power-Down
Supply Voltage Range and Single-Supply
Operation
The EL5191A amplifier can be disabled placing its output in
a high impedance state. When disabled, the amplifier supply
current is reduced to < 150µA. The EL5191A is disabled
when its CE pin is pulled up to within 1V of the positive
supply. Similarly, the amplifier is enabled by floating or
pulling its CE pin to at least 3V below the positive supply. For
±5V supply, this means that an EL5191A amplifier will be
The EL5191 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 the EL5191 will
operate on dual supplies ranging from ±2.5V to ±5V. With
single-supply, the EL5191 will operate from 5V to 10V.
14
EL5191, EL5191A
As supply voltages continue to decrease, it becomes
Current Limiting
necessary to provide input and output voltage ranges that
can get as close as possible to the supply voltages. The
EL5191 has an input range which extends to within 2V of
either supply. So, for example, on ±5V supplies, the EL5191
has an input range which spans ±3V. The output range of
the EL5191 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.
The EL5191 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 Dis s ipation
With the high output drive capability of the EL5191, it is
possible to exceed the 125°C Absolute Maximum junction
temperature under certain very high load current conditions.
Generally speaking when R falls below about 25Ω, it is
L
important to calculate the maximum junction temperature
Video Performance
(T
) for the application to determine if power supply
JMAX
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 9mA
supply current of each EL5191 amplifier. Special circuitry
has been incorporated in the EL5191 to reduce the variation
of output impedance with current output. This results in dG
and dP specifications of 0.035% and 0.04°, while driving
150Ω at a gain of 2.
voltages, load conditions, or package type need to be
modified for the EL5191 to remain in the safe operating area.
These parameters are calculated as follows:
T
= T
+ (θ × n × PD
)
MAX
JMAX
MAX
JA
where:
T
= Maximum ambient temperature
MAX
θ
= Thermal resistance of the package
JA
n = Number of amplifiers in the package
PD = Maximum power dissipation of each amplifier in
MAX
the package
Video performance has also been measured with a 500Ω
load at a gain of +1. Under these conditions, the EL5191 has
dG and dP specifications of 0.02% and 0.02°, respectively.
PD for each amplifier can be calculated as follows:
MAX
V
OUTMAX
----------------------------
PD
= (2 × V × I
) + (V - V ) ×
OUTMAX
MAX
S
SMAX
S
R
L
Output Drive Capability
In spite of its low 9mA of supply current, the EL5191 is
capable of providing a minimum of ±95mA of output current.
With a minimum of ±95mA of output drive, the EL5191 is
capable of driving 50Ω loads to both rails, making it an
excellent choice for driving isolation transformers in
telecommunications applications.
where:
V = Supply voltage
S
I
= Maximum supply current of 1A
SMAX
V
= Maximum output voltage (required)
OUTMAX
Driving Cables and Capacitive Loads
R = Load resistance
L
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 EL5191 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 ) can then be chosen to
G
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.
F
15
EL5191, EL5191A
Typical Application Circuits
0.1µF
+5V
IN+
V
V
+
S
S
OUT
IN-
-
0.1µF
-5V
250Ω
5Ω
0.1µF
+
V
OUT
+5V
IN+
IN-
V
V
S
5Ω
OUT
-
S
0.1µF
-5V
250Ω
250Ω
V
IN
INVERTING 200mA OUTPUT CURRENT DISTRIBUTION AMPLIFIER
250Ω
250Ω
0.1µF
+
+5V
IN+
IN-
V
V
S
OUT
-
S
0.1µF
250Ω
250Ω
-5V
0.1µF
+
+5V
IN+
IN-
V
V
S
V
IN
OUT
V
OUT
-
S
0.1µF
-5V
FAST-SETTLING PRECISION AMPLIFIER
16
EL5191, EL5191A
Typical Application Circuits (Continued)
0.1µF
0.1µF
+5V
+5V
IN+
IN+
V
V
+
-
V
V
+
S
S
OUT
OUT
IN-
IN-
-
S
S
0.1µF
0.1µF
-5V
-5V
0.1µF
250Ω
120Ω
250Ω
250Ω
V
OUT
+
0.1µF
1kΩ
1kΩ
+5V
IN+
240Ω
0.1µF
+5V
IN+
V
V
+
S
0.1µF
120Ω
OUT
V
V
+
-
S
V
OUT
-
IN-
OUT
V
OUT
-
S
IN-
0.1µF
S
-5V
0.1µF
-5V
250Ω
250Ω
V
IN
250Ω
250Ω
Transmitter
Receiver
DIFFERENTIAL LINE DRIVER/RECEIVER
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
17
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