DATASHEET

EL5493, EL5493A
®
Data Sheet
April, 2003
Quad 300MHz Current Feedback Amplifier
with Enable
FN7202.1
Features
• 300MHz -3dB bandwidth
The EL5493 and EL5493A are quad
current feedback amplifiers with a
bandwidth of 300MHz. This makes
these amplifiers ideal for today’s high speed video and
monitor applications.
• 4mA supply current (per amplifier)
• Single and dual supply operation, from 5V to 10V
• Fast enable/disable (EL5493A only)
• Single (EL5193), dual (EL5293), and triple (EL5393)
available
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.
• High speed, 1GHz product available (EL5191)
• High speed, 6mA, 600MHz product available (EL5192,
EL5292, EL5392 & EL5492)
The EL5493A 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.
Applications
• Battery-powered equipment
• Hand-held, portable devices
The EL5493 is offered in the industry-standard 14-pin SO
(0.150") package and the EL5493A in the ultra-small 24-pin
LPP package. Both operate over the industrial temperature
range of -40°C to +85°C.
• Video amplifiers
• Cable drivers
• RGB amplifiers
Pinouts
• Test equipment
EL5493
[14-PIN SO (0.150")]
TOP VIEW
20 IND-
21 OUTD
22 NC
23 OUTA
24 INA-
EL5493A
(24-PIN LPP)
TOP VIEW
NC 1
• Instrumentation
• Current to voltage converters
Ordering Information
19 NC
OUTA 1
PART NUMBER
INA+ 2
18 IND+
INA- 2
CEA 3
17 CED
INA+ 3
16 VS-
VS+ 4
15 CEC
INB+ 5
VS+ 4
Thermal Pad
CEB 5
INB+ 6
14 INC+
OUTB 7
TAPE &
REEL
A
D
- +
+ -
- +
B
+ C
13 IND-
PKG. NO.
EL5493CS
14-Pin SO (0.150")
-
MDP0027
12 IND+
EL5493CS-T7
14-Pin SO (0.150")
7”
MDP0027
11 VS-
EL5493CS-T13
14-Pin SO (0.150")
13”
MDP0027
10 INC+
EL5493ACL
24-Pin LPP
-
MDP0046
9 INC-
EL5493ACL-T7
24-Pin LPP
7”
MDP0046
EL5493ACL-T13
24-Pin LPP
13”
MDP0046
8 OUTC
INC- 12
OUTC 11
NC 10
OUTB 9
13 NC
INB- 8
NC 7
INB- 6
PACKAGE
14 OUTD
1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 321-724-7143 | Intersil (and design) is a registered trademark of Intersil Americas Inc.
Copyright © Intersil Americas Inc. 2003. All Rights Reserved. Elantec is a registered trademark of Elantec Semiconductor, Inc.
All other trademarks mentioned are the property of their respective owners.
EL5493, EL5493A
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
BW1
0.1dB Bandwidth
SR
Slew Rate
VO = -2.5V to +2.5V, AV = +2
20
MHz
2200
V/µs
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
-10
TCVOS
Input Offset Voltage Temperature
Coefficient
ROL
Transimpediance
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
V
OUTPUT CHARACTERISTICS
VO
Output Voltage Swing
RL = 150Ω to GND
±3.4
±3.7
RL = 1kΩ to GND
±3.8
±4.0
V
IOUT
Output Current
RL = 10Ω to GND
95
120
mA
Supply Current - Enabled (per amplifier)
No load, VIN = 0V
3
4
5
mA
ISOFF
Supply Current - Disabled
No load, VIN = 0V
100
150
µA
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
SUPPLY
IsON
2
75
dB
2
µA/V
EL5493, EL5493A
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
MAX
UNIT
ENABLE (EL5493A ONLY)
tEN
Enable Time
40
ns
tDIS
Disable Time (Note 2)
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
VS+ -3
V
VS+ -1
V
NOTES:
1. Standard NTSC test, AC signal amplitude = 286mVP-P, f = 3.58MHz
2. Measured from the application of CE logic signal until the output voltage is at the 50% point between initial and final values
3
EL5493, EL5493A
Typical Performance Curves
Non-Inverting Frequency Response (Phase)
Non-Inverting Frequency Response (Gain)
90
6
AV=1
0
2
AV=2
AV=2
-2
Phase (°)
Normalized Magnitude (dB)
AV=1
AV=5
-6
-90
AV=5
-180
AV=10
AV=10
-270
-10
RF=750Ω
RL=150Ω
-14
1M
RF=750Ω
RL=150Ω
10M
100M
-360
1M
1G
10M
Inverting Frequency Response (Gain)
Inverting Frequency Response (Phase)
6
90
AV=-1
2
AV=-1
AV=-2
0
-2
Phase (°)
Normalized Magnitude (dB)
1G
Frequency (Hz)
Frequency (Hz)
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 (Hz)
6
2pF added
1pF added
2
-2
0pF added
AV=2
RF=500Ω
RL=150Ω
Normalized Magnitude (dB)
6
-10
1M
1G
Frequency Response for Various RL
10
-6
100M
Frequency (Hz)
Frequency Response for Various CIN-
Normalized Magnitude (dB)
100M
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
EL5493, EL5493A
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)
100M
Group Delay vs Frequency
Frequency Response for Various Common-Mode Input
Voltages
6
VCM=3V
Normalized Magnitude (dB)
3
AV=2
RF=500Ω
2.5
Delay (ns)
1G
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
-270
Gain
Phase (°)
-90
PSRR/CMRR (dB)
1M
Magnitude (Ω)
475Ω
2
PSRR+
-20
PSRR-40
CMRR
-60
1k
-360
100
1k
10k
100k
1M
Frequency (Hz)
5
10M
100M
1G
-80
10k
100k
1M
10M
Frequency (Hz)
100M
1G
EL5493, EL5493A
Typical Performance Curves
(Continued)
-3dB Bandwidth vs Supply Voltage for Non-Inverting Gains
-3dB Bandwidth vs Supply Voltage for Inverting Gains
250
400
RF=750Ω
RL=150Ω
350
AV=1
-3dB Bandwidth (MHz)
-3dB Bandwidth (MHz)
200
300
250
200
AV=2
150
AV=5
100
AV=-1
150
AV=-2
100
AV=-5
50
50
RF=500Ω
RL=150Ω
AV=10
0
0
5
7
6
8
9
5
10
6
7
Total Supply Voltage (V)
9
10
Total Supply Voltage (V)
Peaking vs Supply Voltage for Non-Inverting Gains
Peaking vs Supply Voltage for Inverting Gains
4
2.5
RF=750Ω
RL=150Ω
3.5
RF=500Ω
RL=150Ω
2
AV=1
Peaking (dB)
3
Peaking (dB)
8
2.5
2
1.5
1.5
AV=-1
1
AV=2
1
AV=-2
0.5
0.5
AV=10
0
5
6
7
8
9
0
5
10
6
7
Total Supply Voltage (V)
250
RF=750Ω
RL=150Ω
AV=-1
200
AV=1
-3dB Bandwidth (MHz)
-3dB Bandwidth (MHz)
400
300
0
-40
10
-3dB Bandwidth vs Temperature for Inverting Gains
500
100
9
Total Supply Voltage (V)
-3dB Bandwidth vs Temperature for Non-Inverting Gains
200
8
AV=2
AV=5
AV=-2
150
100
AV=-5
50
RF=500Ω
RL=150Ω
AV=10
10
60
Ambient Temperature (°C)
6
110
160
0
-40
10
60
Ambient Temperature (°C)
110
160
EL5493, EL5493A
Typical Performance Curves
(Continued)
Peaking vs Temperature
Voltage and Current Noise vs Frequency
2.5
1k
RL=150Ω
2
Voltage Noise (nV/√Hz)
Current Noise (pA/√Hz)
AV=1
Peaking (dB)
1.5
1
0.5
AV=-1
100
i n+
in-
10
en
0
-0.5
-40
60
10
110
1
100
160
1k
10k
1M
10M
Supply Current vs Supply Voltage
100
10
10
8
Supply Current (mA)
Output Impedance (Ω)
Closed Loop Output Impedance vs Frequency
1
0.1
0.01
6
4
2
0.001
0
100
1k
10k
100k
1M
10M
100M
1G
0
2
Frequency (Hz)
4
6
8
10
12
Supply Voltage (V)
2nd and 3rd Harmonic Distortion vs Frequency
Two-Tone 3rd Order
Input Referred Intermodulation Intercept (IIP3)
-20
25
AV=+2
VOUT=2VP-P
RL=100Ω
20
Input Power Intercept (dBm)
-30
Harmonic Distortion (dBc)
100k
Frequency (Hz)
Ambient Temperature (°C)
-40
2nd Order
Distortion
-50
-60
3rd Order
Distortion
-70
-80
15
10
5
0
-5
-90
1
10
Frequency (MHz)
7
100
AV=+2
RL=150Ω
AV=+2
RL=100Ω
-10
10
100
Frequency (MHz)
EL5493, EL5493A
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
dP
0.02
0
dG (%) or dP (°)
0.01
dG (%) or dP (°)
AV=1
RF=750Ω
RL=500Ω
0.03
dG
-0.01
-0.02
0.01
-0.01
-0.03
-0.02
-0.04
-0.03
-0.05
dG
0
-0.04
-1
-0.5
0
0.5
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
8
Output Voltage Swing (VPP)
Output Voltage Swing (VPP)
RL=500Ω
RL=150Ω
6
4
2
8
RL=500Ω
6
RL=150Ω
4
2
AV=2
AV=2
0
0
1
10
100
1
Frequency (MHz)
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)
10ns/div
EL5493, EL5493A
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 (%)
110
160
110
160
Die Temperature (°C)
PSRR and CMRR vs Temperature
ICMR and IPSR vs Temperature
90
2
80
PSRR
1.5
ICMR+
ICMR/IPSR (µA/V)
70
PSRR/CMRR (dB)
60
60
CMRR
50
40
1
IPSR
0.5
30
ICMR-
0
20
10
-40
10
60
110
-0.5
-40
160
10
60
Die Temperature (°C)
Die Temperature (°C)
Offset Voltage vs Temperature
Input Current vs Temperature
2
60
40
Input Current (µA)
VOS (mV)
1
0
20
IB0
IB+
-20
-1
-40
-2
-40
10
60
Die Temperature (°C)
9
110
160
-60
-40
10
60
Temperature (°C)
110
160
EL5493, EL5493A
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
10
60
110
0
-40
160
60
10
Temperature (°C)
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
4
-3.7
3.9
-3.8
VOUT (V)
VOUT (V)
1kΩ
3.8
3.7
-3.9
-4
150Ω
1kΩ
3.6
-4.1
3.5
-40
10
60
110
-4.2
-40
160
60
10
Temperature (°C)
110
160
Temperature (°C)
Output Current vs Temperature
Slew Rate vs Temperature
130
4000
Sink
Slew Rate (V/µS)
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
EL5493, EL5493A
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 (Single
Layer) Test Board
Disable Response
1
833mW
Power Dissipation (W)
0.8
500mV/div
714mW
0.6
SO14 (0.150”)
120°C/W
LPP24
140°C/W
0.4
0.2
5V/div
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 (4 layer) Test
Board - LPP exposed diepad soldered to PCB per JESD51-5
3
2.703W
4
P2
LP
/W
°C
37
Power Dissipation (W)
2.5
2
1.5
1.136W
SO
14
(0
1
88°
C/
.15
0”)
W
0.5
0
0
25
50
75 85
100
Ambient Temperature (°C)
11
125
150
125
150
EL5493, EL5493A
Pin Descriptions
14-PIN SO
(0.150")
24-PIN LPP
PIN NAME
1
23
OUTA
FUNCTION
EQUIVALENT CIRCUIT
Output, channel A
VS+
OUT
VSCircuit 1
2
24
INA-
Inverting input, channel A
VS+
IN+
IN-
VSCircuit 2
3
2
INA+
Non-inverting input, channel A
3
CEA
Chip enable, channel A
(see circuit 2)
VS+
CE
VSCircuit 3
4
4
VS+
Positive supply
5
CEB
Chip enable, channel B
(see circuit 3)
5
6
INB+
Non-inverting input, channel B
(see circuit 2)
6
8
INB-
Inverting input, channel B
(see circuit 2)
7
9
OUTB
Output, channel B
(see circuit 1)
8
11
OUTC
Output, channel C
(see circuit 1)
9
12
INC-
Inverting input, channel C
(see circuit 2)
10
14
INC+
Non-inverting input, channel C
(see circuit 2)
15
CEC
Chip enable, channel C
(see circuit 3)
16
VS-
Negative supply
17
CED
Chip enable, channel D
(see circuit 3)
12
18
IND+
Non-inverting input, channel D
(see circuit 2)
13
20
IND-
Inverting input, channel D
(see circuit 1)
14
21
OUTD
Output, channel D
(see circuit 1)
1, 7, 10, 13,
19, 22
NC
11
12
No connection
EL5493, EL5493A
Applications Information
Product Description
The EL5493 is a current-feedback operational amplifier that
offers a wide -3dB bandwidth of 300MHz and a low supply
current of 4mA per amplifier. The EL5493 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 its current-feedback topology, the
EL5493 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 EL5493 the ideal choice for many low-power/highbandwidth applications such as portable, handheld, or
battery-powered equipment.
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 also include single, dual,
triple, and quad amp packages.
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.
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 (0.150")
package, should be avoided if possible. Sockets add
parasitic inductance and capacitance which will result in
additional peaking and overshoot.
Disable/Power-Down
The EL5493A amplifier can be disabled placing its output in
a high impedance state. When disabled, the amplifier supply
current is reduced to < 600µA. The EL5493A 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 EL5493A amplifier will be
enabled when CE is 2V or less, and disabled when CE is
13
above 4V. Although the logic levels are not standard TTL,
this choice of logic voltages allows the EL5493A 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 EL5493 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 EL5493 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
EL5493 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,
bandwidth and peaking can be easily modified by varying the
value of the feedback resistor.
Because the EL5493 is a current-feedback amplifier, its gainbandwidth product is not a constant for different closed-loop
gains. This feature actually allows the EL5493 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 EL5493 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 EL5493 will operate
on dual supplies ranging from ±2.5V to ±5V. With singlesupply, the EL5493 will operate from 5V to 10V.
As supply voltages continue to decrease, it becomes
necessary to provide input and output voltage ranges that
EL5493, EL5493A
can get as close as possible to the supply voltages. The
EL5493 has an input range which extends to within 2V of
either supply. So, for example, on +5V supplies, the EL5493
has an input range which spans ±3V. The output range of the
EL5493 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 EL5493 amplifier. Special circuitry has been
incorporated in the EL5493 to reduce the variation of output
impedance with current output. This results in dG and dP
specifications of 0.03% and 0.04°C, 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 EL5493 has
dG and dP specifications of 0.03% and 0.04°C.
Output Drive Capability
In spite of its low 4mA of supply current, the EL5493 is
capable of providing a minimum of ±95mA of output current.
With a minimum of ±95mA of output drive, the EL5493 is
capable of driving 50Ω loads to both rails, making it an
excellent choice for driving isolation transformers in
telecommunications applications.
possible to simply increase the value of the feedback resistor
(RF) to reduce the peaking.
Current Limiting
The EL5493 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 EL5493, 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 EL5493 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
PDMAX for each amplifier can be calculated as follows:
V OUTMAX
PD MAX = ( 2 × V S × I SMAX ) + ( V S - V OUTMAX ) × ---------------------------RL
where:
Driving Cables and Capacitive Loads
VS = Supply voltage
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 EL5493 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
ISMAX = Maximum supply current of 1A
VOUTMAX = Maximum output voltage (required)
RL = Load resistance
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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
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