Intersil EL5293ACY-T7 Dual 300mhz current feedback amplifier with enable Datasheet

W
R NE
D FO 5263
E
D
EL
EN
260,
OMM
REC SEE EL5
T
O
N
®
Data Sheet
EL5293, EL5293A
September 30, 2005
Dual 300MHz Current Feedback Amplifier
with Enable
The EL5293 and EL5293A represent dual current feedback
amplifiers with a bandwidth of 300MHz. This makes these
amplifiers ideal for today’s high speed video and monitor
applications.
With a supply current of just 4mA per amplifier and the ability
to run from a single supply voltage from 5V to 10V, these
amplifiers are also ideal for hand held, portable or battery
powered equipment.
The EL5293A 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.
The EL5293 is offered in the industry-standard 8-pin SO
package and the space-saving 8-pin MSOP package. The
EL5293A is available in a 10-pin MSOP package and all
operate over the industrial temperature range of -40°C to
+85°C.
FN7193.2
Features
• 300MHz -3dB bandwidth
• 4mA supply current (per amplifier)
• Single and dual supply operation, from 5V to 10V
• Fast enable/disable (EL5293A only)
• Single (EL5193) and triple (EL5393) available
• High speed, 1GHz product available (EL5191)
• High speed, 6mA, 600MHz product available (EL5192,
EL5292, and EL5392)
• Pb-free plus anneal available (RoHS compliant)
Applications
• Battery-powered equipment
• Hand-held, portable devices
• Video amplifiers
• Cable drivers
• RGB amplifiers
Ordering Information
PART
PART NUMBER MARKING
IGNS
DES
PACKAGE
TAPE &
REEL
PKG.
DWG. #
• Test equipment
• Instrumentation
EL5293CS
5293CS
8-Pin SO
-
MDP0027
• Current to voltage converters
EL5293CS-T7
5293CS
8-Pin SO
7”
MDP0027
Pinouts
EL5293CS-T13
5293CS
8-Pin SO
13”
MDP0027
EL5293CSZ
(See Note)
5293CSZ
8-Pin SO
(Pb-free)
-
MDP0027
EL5293CSZ-T7
(See Note)
5293CSZ
8-Pin SO
(Pb-free)
7”
MDP0027
EL5293CSZ-T13 5293CSZ
(See Note)
8-Pin SO
(Pb-free)
13”
MDP0027
OUTA 1
INA- 2
8 VS+
+
7 OUTB
6 INB-
INA+ 3
EL5293CY
V
8-Pin MSOP
-
MDP0043
EL5293CY-T7
V
8-Pin MSOP
7”
MDP0043
EL5293CY-T13
V
8-Pin MSOP
13”
MDP0043
EL5293ACY
Y
10-Pin MSOP
-
MDP0043
EL5293ACY-T7
Y
10-Pin MSOP
7”
MDP0043
EL5293ACY-T13 Y
10-Pin MSOP
13”
MDP0043
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.
1
EL5293
(8-PIN SO, MSOP)
TOP VIEW
+
VS- 4
5 INB+
EL5293A
(10-PIN MSOP)
TOP VIEW
INA+ 1
CEA 2
10 INA+
8 VS+
VS- 3
CEB 4
INB+ 5
9 OUTA
+
-
7 OUTB
6 INB-
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. 2003, 2005. All Rights Reserved
All other trademarks mentioned are the property of their respective owners.
EL5293, EL5293A
Absolute Maximum Ratings (TA = 25°C)
Supply Voltage between VS+ and VS- . . . . . . . . . . . . . . . . . . . . .11V
Maximum Continuous Output Current . . . . . . . . . . . . . . . . . . . 50mA
Operating Junction Temperature . . . . . . . . . . . . . . . . . . . . . . . 125°C
Power Dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . See Curves
Pin Voltages. . . . . . . . . . . . . . . . . . . . . . . . .VS- - 0.5V to VS+ +0.5V
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: TJ = TC = TA
Electrical Specifications
VS+ = +5V, VS- = -5V, RF = 750Ω for AV = 1, RF = 375Ω for AV = 2, RL = 150Ω, TA = 25°C unless otherwise
specified.
PARAMETER
DESCRIPTION
CONDITIONS
MIN
TYP
MAX
UNIT
AC PERFORMANCE
BW
-3dB Bandwidth
AV = +1
300
MHz
AV = +2
200
MHz
20
MHz
2200
V/µs
BW1
0.1dB Bandwidth
SR
Slew Rate
VO = -2.5V to +2.5V, AV = +2
tS
0.1% Settling Time
VOUT = -2.5V to +2.5V, AV = -1
12
ns
CS
Channel Separation
f = 5MHz
60
dB
eN
Input Voltage Noise
4.4
nV/√Hz
iN-
IN- Input Current Noise
17
pA/√Hz
iN+
IN+ Input Current Noise
50
pA/√Hz
dG
Differential Gain Error (Note 1)
AV = +2
0.03
%
dP
Differential Phase Error (Note 1)
AV = +2
0.04
°
1900
DC PERFORMANCE
VOS
Offset Voltage
TCVOS
Input Offset Voltage Temperature
Coefficient
ROL
Transimpediance
-10
Measured from TMIN to TMAX
1
10
mV
5
µV/°C
300
600
kΩ
INPUT CHARACTERISTICS
CMIR
Common Mode Input Range
±3
±3.3
V
CMRR
Common Mode Rejection Ratio
42
50
dB
+IIN
+ Input Current
-60
1
80
µA
-IIN
- Input Current
-35
1
35
µA
RIN
Input Resistance
45
kΩ
CIN
Input Capacitance
0.5
pF
OUTPUT CHARACTERISTICS
VO
RL = 150Ω to GND
±3.4
±3.7
V
RL = 1kΩ to GND
±3.8
±4.0
V
Output Current
RL = 10Ω to GND
95
120
mA
ISON
Supply Current - Enabled (per amplifier)
No load, VIN = 0V
3
4
5
mA
ISOFF
Supply Current - Disabled (per amplifier)
No load, VIN = 0V
100
150
µA
IOUT
Output Voltage Swing
SUPPLY
2
EL5293, EL5293A
Electrical Specifications
VS+ = +5V, VS- = -5V, RF = 750Ω for AV = 1, RF = 375Ω for AV = 2, RL = 150Ω, TA = 25°C unless otherwise
specified. (Continued)
PARAMETER
DESCRIPTION
CONDITIONS
MIN
TYP
75
PSRR
Power Supply Rejection Ratio
DC, VS = ±4.75V to ±5.25V
55
-IPSR
- Input Current Power Supply Rejection
DC, VS = ±4.75V to ±5.25V
-2
MAX
UNIT
dB
2
µA/V
ENABLE (EL5293A ONLY)
tEN
Enable Time
40
ns
tDIS
Disable Time
600
ns
IIHCE
CE Pin Input High Current
CE = VS+
0.8
6
µA
IILCE
CE Pin Input Low Current
CE = VS-
0
-0.1
µA
VIHCE
CE Input High Voltage for Power-down
VILCE
CE Input Low Voltage for Power-down
NOTE:
1. Standard NTSC test, AC signal amplitude = 286mVP-P, f = 3.58MHz
3
VS+ - 1
V
VS+ - 3
V
EL5293, EL5293A
Typical Performance Curves
Non-Inverting Frequency Response (Gain)
Non-Inverting Frequency Response (Phase)
6
90
AV=1
0
2
AV=2
AV=2
Phase (°)
Normalized Magnitude (dB)
AV=1
-2
AV=5
-6
-90
AV=5
-180
AV=10
AV=10
-10
-270
RF=750Ω
RL=150Ω
-14
1M
RF=750Ω
RL=150Ω
10M
100M
-360
1M
1G
10M
Frequency (Hz)
Inverting Frequency Response (Gain)
90
AV=-1
2
AV=-1
AV=-2
0
Phase (°)
Normalized Magnitude (dB)
1G
Inverting Frequency Response (Phase)
6
-2
AV=-3
-6
-10
-90
AV=-2
AV=-3
-180
-270
RF=500Ω
RL=150Ω
-14
1M
RF=500Ω
RL=150Ω
10M
100M
-360
1M
1G
10M
Frequency Response for Various CIN-
2pF added
1pF added
2
-2
0pF added
AV=2
RF=500Ω
RL=150Ω
Normalized Magnitude (dB)
6
6
-10
1M
1G
Frequency Response for Various RL
10
-6
100M
Frequency (Hz)
Frequency (Hz)
Normalized Magnitude (dB)
100M
Frequency (Hz)
2
RL=100Ω
-2
RL=500Ω
RL=150Ω
-6
-10
AV=2
RF=500Ω
10M
100M
Frequency (Hz)
4
1G
-14
1M
10M
100M
Frequency (Hz)
1G
EL5293, EL5293A
Typical Performance Curves
(Continued)
Frequency Response for Various CL
Frequency Response for Various RF
6
AV=2
RL=150Ω
RF=RG=500Ω
10
33pF
340Ω
Normalized Magnitude (dB)
Normalized Magnitude (dB)
14
22pF
6
15pF
2
8pF
-2
620Ω
-2
750Ω
-6
1.2kΩ
-10
AV=2
RG=RF
RL=150Ω
0pF
-6
1M
10M
100M
-14
1M
1G
10M
Frequency (Hz)
Group Delay vs Frequency
1G
Frequency Response for Various Common-Mode Input
Voltages
6
VCM=3V
Normalized Magnitude (dB)
3
AV=2
RF=500Ω
2.5
Delay (ns)
100M
Frequency (Hz)
3.5
2
1.5
AV=1
RF=750Ω
1
0
1M
10M
100M
-2
VCM=-3V
-6
-10
AV=2
RF=500Ω
RL=150Ω
-14
1M
1G
VCM=0V
2
0.5
10M
Frequency (Hz)
100M
1G
Frequency (Hz)
Transimpedance (ROL) vs Frequency
PSRR and CMRR vs Frequency
20
10M
Phase
0
0
100k
-180
10k
Gain
-270
1k
Phase (°)
-90
PSRR/CMRR (dB)
1M
Magnitude (Ω)
475Ω
2
PSRR+
-20
PSRR-40
CMRR
-60
-360
100
1k
10k
100k
1M
10M
Frequency (Hz)
5
100M
1G
-80
10k
100k
1M
10M
Frequency (Hz)
100M
1G
EL5293, EL5293A
Typical Performance Curves
(Continued)
-3dB Bandwidth vs Supply Voltage for Non-Inverting
Gains
-3dB Bandwidth vs Supply Voltage for Inverting Gains
400
250
RF=750Ω
RL=150Ω
AV=1
-3dB Bandwidth (MHz)
-3dB Bandwidth (MHz)
350
300
250
200
AV=2
150
AV=5
100
200
AV=-1
150
AV=-2
100
AV=-5
50
50
RF=500Ω
RL=150Ω
AV=10
0
5
0
6
7
8
9
10
5
6
7
Total Supply Voltage (V)
8
9
10
Total Supply Voltage (V)
Peaking vs Supply Voltage for Inverting Gains
Peaking vs Supply Voltage for Non-Inverting Gains
4
2.5
RF=750Ω
RL=150Ω
AV=1
3.5
RF=500Ω
RL=150Ω
2
Peaking (dB)
Peaking (dB)
3
2.5
2
1.5
AV=2
1
1.5
AV=-1
1
AV=-2
0.5
0.5
AV=10
0
5
6
7
8
9
0
5
10
6
7
-3dB Bandwidth vs Temperature for Non-Inverting
Gains
10
250
RF=750Ω
RL=150Ω
400
200
-3dB Bandwidth (MHz)
-3dB Bandwidth (MHz)
9
-3dB Bandwidth vs Temperature for Inverting Gains
500
AV=1
300
200
AV=2
100
AV=5
0
-40
8
Total Supply Voltage (V)
Total Supply Voltage (V)
60
110
Ambient Temperature (°C)
6
AV=-2
150
100
AV=-5
50
RF=500Ω
RL=150Ω
AV=10
10
AV=-1
160
0
-40
10
60
110
Ambient Temperature (°C)
160
EL5293, EL5293A
Typical Performance Curves
(Continued)
Peaking vs Temperature
Voltage and Current Noise vs Frequency
2.5
1k
RL=150Ω
Voltage Noise (nV/√Hz)
Current Noise (pA/√Hz)
2
Peaking (dB)
AV=1
1.5
1
0.5
AV=-1
in+
100
in10
en
0
-0.5
-40
10
60
110
1
100
160
1k
10k
100
10
10
8
Supply Current (mA)
Output Impedance (Ω)
1M
10M
Supply Current vs Supply Voltage
Closed Loop Output Impedance vs Frequency
1
0.1
0.01
6
4
2
0.001
0
100
1k
10k
100k
1M
10M
100M
0
1G
2
4
6
8
10
12
Supply Voltage (V)
Frequency (Hz)
2nd and 3rd Harmonic Distortion vs Frequency
Two-Tone 3rd Order
Input Referred Intermodulation Intercept (IIP3)
-20
25
Input Power Intercept (dBm)
AV=+2
VOUT=2VP-P
RL=100Ω
-30
Harmonic Distortion (dBc)
100k
Frequency (Hz)
Ambient Temperature (°C)
-40
2nd Order
Distortion
-50
3rd Order
Distortion
-60
-70
-80
-90
1
10
Frequency (MHz)
7
100
20
AV=+2
RL=150Ω
15
10
5
0
-5
AV=+2
RL=100Ω
-10
10
100
Frequency (MHz)
EL5293, EL5293A
Typical Performance Curves
(Continued)
Differential Gain/Phase vs DC Input
Voltage at 3.58MHz
Differential Gain/Phase vs DC Input
Voltage at 3.58MHz
0.03
0.04
AV=2
RF=RG=500Ω
RL=150Ω
0.02
dP
0.02
0
dG (%) or dP (°)
0.01
dG (%) or dP (°)
AV=1
RF=750Ω
RL=500Ω
0.03
dP
dG
-0.01
-0.02
0.01
-0.01
-0.03
-0.02
-0.04
-0.03
-0.05
-1
-0.5
0
0.5
dG
0
-0.04
-1
1
-0.5
DC Input Voltage
0
0.5
1
DC Input Voltage
Output Voltage Swing vs Frequency
THD<1%
Output Voltage Swing vs Frequency
THD<0.1%
10
10
Output Voltage Swing (VPP)
Output Voltage Swing (VPP)
RL=500Ω
8
RL=150Ω
6
4
2
8
RL=500Ω
6
RL=150Ω
4
2
AV=2
AV=2
0
0
1
10
1
100
10
Small Signal Step Response
Large Signal Step Response
VS=±5V
RL=150Ω
AV=2
RF=RG=500Ω
200mV/div
VS=±5V
RL=150Ω
AV=2
RF=RG=500Ω
1V/div
10ns/div
8
100
Frequency (MHz)
Frequency (MHz)
10ns/div
EL5293, EL5293A
Typical Performance Curves
(Continued)
Settling Time vs Settling Accuracy
Transimpedance (RoI) vs Temperature
25
625
AV=2
RF=RG=500Ω
RL=150Ω
VSTEP=5VP-P output
600
15
RoI (kΩ)
Settling Time (ns)
20
10
575
550
5
0
0.01
0.1
525
-40
1
10
Settling Accuracy (%)
60
110
160
110
160
Die Temperature (°C)
PSRR and CMRR vs Temperature
ICMR and IPSR vs Temperature
90
2
80
PSRR
ICMR+
1.5
ICMR/IPSR (µA/V)
PSRR/CMRR (dB)
70
60
50
CMRR
40
30
1
IPSR
0.5
ICMR-
0
20
10
-40
10
60
110
-0.5
-40
160
10
Die Temperature (°C)
60
Die Temperature (°C)
Offset Voltage vs Temperature
Input Current vs Temperature
2
60
40
Input Current (µA)
VOS (mV)
1
0
-1
20
IB0
-20
IB+
-40
-2
-40
10
60
Die Temperature (°C)
9
110
160
-60
-40
10
60
Temperature (°C)
110
160
EL5293, EL5293A
Typical Performance Curves
(Continued)
Positive Input Resistance vs Temperature
Supply Current vs Temperature
60
5
50
Supply Current (mA)
4
RIN+ (kΩ)
40
30
20
3
2
1
10
0
-40
60
10
110
0
-40
160
10
Temperature (°C)
60
110
160
Temperature (°C)
Positive Output Swing vs Temperature for Various
Loads
Negative Output Swing vs Temperature for Various
Loads
4.2
-3.5
4.1
150Ω
-3.6
1kΩ
-3.7
VOUT (V)
VOUT (V)
4
3.9
3.8
3.7
-3.8
-3.9
-4
150Ω
1kΩ
3.6
-4.1
3.5
-40
10
60
110
-4.2
-40
160
10
Temperature (°C)
60
110
160
Temperature (°C)
Output Current vs Temperature
Slew Rate vs Temperature
130
4000
Slew Rate (V/µS)
Sink
IOUT (mA)
125
Source
120
3500
3000
AV=2
RF=RG=500Ω
RL=150Ω
115
-40
10
60
Die Temperature (°C)
10
110
160
2500
-40
10
60
Die Temperature (°C)
110
160
EL5293, EL5293A
Typical Performance Curves
(Continued)
Channel-to-Channel Isolation vs Frequency
Enable Response
0
Gain (dB)
-20
500mV/div
-40
-60
5V/div
-80
-100
100k
1M
10M
100M
400M
20ns/div
Frequency (Hz)
Package Power Dissipation vs Ambient
Temperature - JEDEC JESD51-3 Low Effective
Thermal Conductivity Test Board
Disable Response
1
Power Dissipation (W)
0.9
500mV/div
5V/div
0.8
0.7
625mW
0.6
SO8
θJA=160°C/W
486mW
0.5
0.4
0.3
MSOP8/10
θJA=206°C/W
0.2
0.1
0
0
400ns/div
25
50
75 85 100
Ambient Temperature (°C)
Package Power Dissipation vs Ambient
Temperature - JEDEC JESD51-7 High Effective
Thermal Conductivity Test Board
1
Power Dissipation (W)
909mW
0.8
870mW
SO8
θJA=110°C/W
0.6
MSOP8/10
θJA=115°C/W
0.4
0.2
0
0
25
50
75 85
100
Ambient Temperature (°C)
11
125
150
125
150
EL5293, EL5293A
Pin Descriptions
8-PIN SO &
MSOP
10-PIN
MSOP
PIN NAME
1
9
OUTA
FUNCTION
EQUIVALENT CIRCUIT
Output, channel A
VS+
OUT
VSCircuit 1
2
10
INA-
Inverting input, channel A
VS+
IN+
IN-
VSCircuit 2
3
1
INA+
Non-inverting input, channel A
2
CEA
Chip enable, channel A
(see circuit 2)
VS+
CE
VSCircuit 3
4
3
VS-
Negative supply
4
CEB
Chip enable, channel B
(see circuit 3)
5
5
INB+
Non-inverting input, channel B
(see circuit 2)
6
6
INB-
Inverting input, channel B
(see circuit 2)
7
7
OUTB
Output, channel B
(see circuit 1)
8
8
VS+
Positive supply
Applications Information
Product Description
The EL5293 is a current-feedback operational amplifier that
offers a wide -3dB bandwidth of 300MHz and a low supply
current of 4mA per amplifier. The EL5293 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
EL5293 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 EL5293 the ideal choice for many low-power/highbandwidth applications such as portable, handheld, or
battery-powered equipment.
12
For varying bandwidth needs, consider the EL5191 with
1GHz on a 9mA supply current or the EL5192 with 600MHz
on a 6mA supply current. Versions include single, dual, and
triple amp packages with 5-pin SOT23, 16-pin QSOP, and 8pin or 16-pin SO outlines.
Power Supply Bypassing 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.
EL5293, EL5293A
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.
Disable/Power-Down
The EL5293A amplifier can be disabled placing its output in
a high impedance state. When disabled, the amplifier supply
current is reduced to < 300µA. The EL5293A 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 EL5293A amplifier will be
enabled when CE is 2V or less, and disabled when CE is
above 4V. Although the logic levels are not standard TTL,
this choice of logic voltages allows the EL5293A to be
enabled by tying CE to ground, even in 5V single supply
applications. The CE pin can be driven from CMOS outputs.
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 largevalue feedback and gain resistors exacerbates the problem
by further lowering the pole frequency (increasing the
possibility of oscillation.)
The EL5293 has been optimized with a 475Ω 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.
Feedback Resistor Values
The EL5293 has been designed and specified at a gain of +2
with RF approximately 500Ω. This value of feedback resistor
gives 200MHz of -3dB bandwidth at AV=2 with 2dB of
peaking. With AV=-2, an RF of approximately 500Ω gives
175MHz of bandwidth with 0.2dB of peaking. Since the
EL5293 is a current-feedback amplifier, 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,
13
bandwidth and peaking can be easily modified by varying the
value of the feedback resistor.
Because the EL5293 is a current-feedback amplifier, its gainbandwidth product is not a constant for different closed-loop
gains. This feature actually allows the EL5293 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 RF below the
specified 475Ω 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 EL5293 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 EL5293 will operate
on dual supplies ranging from ±2.5V to ±5V. With singlesupply, the EL5293 will operate from 5V to 10V.
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
EL5293 has an input range which extends to within 2V of
either supply. So, for example, on +5V supplies, the EL5293
has an input range which spans ±3V. The output range of the
EL5293 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.
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. 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 4mA supply
current of each EL5293 amplifier. Special circuitry has been
incorporated in the EL5293 to reduce the variation of output
impedance with current output. This results in dG and dP
specifications of 0.03% and 0.04°, 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 EL5293 has
dG and dP specifications of 0.03% and 0.04°.
Output Drive Capability
In spite of its low 4mA of supply current, the EL5293 is
capable of providing a minimum of ±95mA of output current.
With a minimum of ±95mA of output drive, the EL5293 is
capable of driving 50Ω loads to both rails, making it an
EL5293, EL5293A
excellent choice for driving isolation transformers in
telecommunications applications.
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 EL5293 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.
PDMAX for each amplifier can be calculated as follows:
V OUTMAX
PD MAX = ( 2 × V S × I SMAX ) + ( V S - V OUTMAX ) × ---------------------------R
L
where:
VS = Supply voltage
ISMAX = Maximum supply current of 1A
VOUTMAX = Maximum output voltage (required)
RL = Load resistance
Current Limiting
The EL5293 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 Dissipation
With the high output drive capability of the EL5293, it is
possible to exceed the 125°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 EL5293 to remain in the safe operating area.
These parameters are calculated as follows:
T JMAX = T MAX + ( θ JA × n × PD MAX )
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
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
14