INTERSIL EL5371IUZ

EL5171, EL5371
®
Data Sheet
August 10, 2010
FN7307.7
250MHz Differential Twisted-Pair Drivers
Features
The EL5171 and EL5371 are single and triple bandwidth
amplifiers with an output in differential form. They are primarily
targeted for applications such as driving twisted-pair lines in
component video applications. The input signal is single-ended
and the outputs are always differential.
• Fully differential outputs and feedback
On the EL5171 and EL5371, two feedback inputs provide
the user with the ability to set the gain of each device (stable
at minimum gain of one). For a fixed gain of two, please see
EL5170 and EL5370.
• Low distortion at 5MHz
The output common mode level for each channel is set by
the associated VREF pin, which have a -3dB bandwidth of
over 50MHz. Generally, these pins are grounded but can be
tied to any voltage reference.
• Low power - 8mA per channel
All outputs are short circuit protected to withstand temporary
overload condition.
• Twisted-pair driver
The EL5171 and EL5371 are specified for operation over the
full -40°C to +85°C temperature range.
• VGA over twisted-pair
PART
MARKING
• 250MHz 3dB bandwidth
• 800V/µs slew rate
• Single 5V or dual ±5V supplies
• 90mA maximum output current
• Pb-free available (RoHS compliant)
Applications
• Differential line driver
• ADSL/HDSL driver
Ordering Information
PART
NUMBER
• Input range ±2.3V typ.
• Single-ended to differential amplification
PACKAGE
PKG.
DWG. #
EL5171IS*
5171IS
8 Ld SOIC
MDP0027
EL5171ISZ*
(Note)
5171ISZ
8 Ld SOIC
(Pb-free)
MDP0027
EL5371IU*
EL5371IU
28 Ld QSOP
MDP0040
EL5371IUZ*
(Note)
EL5371IUZ
28 Ld QSOP
(Pb-free)
MDP0040
*Add “-T7” or “-T13” suffix for tape and reel. Please refer to TB347
for details on reel specifications.
NOTE: These Intersil Pb-free plastic packaged products employ
special Pb-free material sets, molding compounds/die attach
materials, and 100% matte tin plate plus anneal (e3 termination
finish, which is 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.
• Transmission of analog signals in a noisy environment
Pinouts
EL5371
(28 LD QSOP)
TOP VIEW
EL5171
(8 LD SOIC)
TOP VIEW
FBP 1
IN+ 2
REF 3
FBN 4
8 OUT+
+
-
NC 1
7 VS-
INP1 2
6 VS+
INN1 3
5 OUT-
REF1 4
+
-
27 FBP1
26 FBN1
25 OUT1B
NC 5
24 VSP
INP2 6
23 VSN
INN2 7
22 OUT2
REF2 8
NC 9
+
-
21 FBP2
20 FBN2
INP3 10
19 OUT2B
INN3 11
18 OUT3
REF3 12
NC 13
EN 14
1
28 OUT1
+
-
17 FBP3
16 FBN3
15 OUT3B
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. 2004-2006, 2010. All Rights Reserved
All other trademarks mentioned are the property of their respective owners.
EL5171, EL5371
Absolute Maximum Ratings (TA = +25°C)
Thermal Information
Supply Voltage (VS+ to VS-) . . . . . . . . . . . . . . . . . . . . . . . . . . . .12V
Supply Voltage Rate-of-rise (dV/dT) . . . . . . . . . . . . . . . . . . . . 1V/µs
Input Voltage (IN+, IN- to VS+, VS-). . . . . . VS- - 0.3V to VS+ + 0.3V
Differential Input Voltage (IN+ to IN-) . . . . . . . . . . . . . . . . . . . . ±4.8V
Maximum Output Current. . . . . . . . . . . . . . . . . . . . . . . . . . . . ±60mA
Operating Junction Temperature . . . . . . . . . . . . . . . . . . . . . . +135°C
Ambient Operating Temperature . . . . . . . . . . . . . . . .-40°C to +85°C
Storage Temperature Range . . . . . . . . . . . . . . . . . .-65°C to +150°C
Power Dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . See Curves
Pb-Free Reflow Profile. . . . . . . . . . . . . . . . . . . . . . . . .see link below
http://www.intersil.com/pbfree/Pb-FreeReflow.asp
CAUTION: Do not operate at or near the maximum ratings listed for extended periods of time. Exposure to such conditions may adversely impact product reliability and
result in failures not covered by warranty.
IMPORTANT NOTE: All parameters having Min/Max specifications are guaranteed. Typ values are for information purposes only. Unless otherwise noted, all tests are
at the specified temperature and are pulsed tests, therefore: TJ = TC = TA
Electrical Specifications
VS+ = +5V, VS- = -5V, TA = +25°C, VIN = 0V, RLD = 1kΩ, RF = 0, RG = OPEN, CLD = 2.7pF, Unless Otherwise
Specified.
PARAMETER
DESCRIPTION
CONDITIONS
MIN
TYP
MAX
UNIT
AC PERFORMANCE
BW
-3dB Bandwidth
AV = 1, CLD = 2.7pF
250
MHz
AV = 2, RF = 500, CLD = 2.7pF
60
MHz
AV = 10, RF = 500, CLD = 2.7pF
10
MHz
BW
±0.1dB Bandwidth
AV = 1, CLD = 2.7pF
50
MHz
SR
Slew Rate (EL5171)
VOUT = 3VP-P, 20% to 80%
600
800
1000
V/µs
Slew Rate (EL5371)
VOUT = 3VP-P, 20% to 80%
540
700
1000
V/µs
tSTL
Settling Time to 0.1%
VOUT = 2VP-P
tOVR
GBWP
10
ns
Output Overdrive Recovery Time
20
ns
Gain Bandwidth Product
100
MHz
AV =1, CLD = 2.7pF
50
MHz
VREFBW (-3dB) VREF -3dB Bandwidth
VREFSR+
VREF Slew Rate - Rise
VOUT = 2VP-P, 20% to 80%
90
V/µs
VREFSR-
VREF Slew Rate - Fall
VOUT = 2VP-P, 20% to 80%
50
V/µs
VN
Input Voltage Noise
at 10kHz
26
nV/√Hz
IN
Input Current Noise
at 10kHz
2
pA/√Hz
HD2
Second Harmonic Distortion
VOUT = 2VP-P, 5MHz
-94
dBc
VOUT = 2VP-P, 20MHz
-94
dBc
VOUT = 2VP-P, 5MHz
-77
dBc
VOUT = 2VP-P, 20MHz
-75
dBc
HD3
Third Harmonic Distortion
dG
Differential Gain at 3.58MHz
RL = 300Ω, AV = 2
0.1
%
dθ
Differential Phase at 3.58MHz
RL = 300Ω, AV = 2
0.5
°
eS
Channel Separation
at f = 1MHz
90
dB
INPUT CHARACTERISTICS
VOS
Input Referred Offset Voltage
IIN
Input Bias Current (VIN+, VIN-)
IREF
Input Bias Current (VREF)
RIN
Differential Input Resistance
±25
mV
-14
-6
-3
µA
0.5
1.3
4
µA
300
CIN
Differential Input Capacitance
DMIR
Differential Mode Input Range
CMIR+
Common Mode Positive Input Range at VIN+, VIN-
CMIR-
Common Mode Negative Input Range at VIN+, VIN- Tested only for EL5371
2
±1.5
kΩ
1
Tested only for EL5371
±2.1
±2.3
3.1
3.4
-4.5
pF
±2.5
V
V
-4.2
V
FN7307.7
August 10, 2010
EL5171, EL5371
Electrical Specifications
VS+ = +5V, VS- = -5V, TA = +25°C, VIN = 0V, RLD = 1kΩ, RF = 0, RG = OPEN, CLD = 2.7pF, Unless Otherwise
Specified. (Continued)
PARAMETER
DESCRIPTION
CONDITIONS
VREFIN +
Positive Reference Input Voltage Range (EL5371)
VIN+ = VIN- = 0V
VREFIN -
Negative Reference Input Voltage Range (EL5371)
VIN+ = VIN- = 0V
VREFOS
Output Offset Relative to VREF (EL5371)
CMRR
Input Common Mode Rejection Ratio (EL5371)
VIN = ±2.5V
Gain
Gain Accuracy
MIN
TYP
3.5
±3.8
MAX
UNIT
V
-3.3
-3
V
±60
±100
mV
70
82
dB
VIN = 1 (EL5171)
0.981
0.996
1.011
V
VIN = 1 (EL5371)
0.978
0.993
1.008
V
OUTPUT CHARACTERISTICS
Output Voltage Swing
VOUT
IOUT(Max)
ROUT
RL = 500Ω to GND (EL5171)
Maximum Output Current
±3.4
V
V
RL = 500Ω to GND (EL5371)
±3.6
±3.9
RL = 10Ω, VIN = ±3.24 (EL5171)
±70
±90
±120
mA
RL = 10Ω, VIN = ±3.24 (EL5371)
±50
±70
±90
mA
Output Impedance
130
mΩ
SUPPLY
VSUPPLY
Supply Operating Range
IS(ON)
Power Supply Current - Per Channel
VS+ to VS-
IS(OFF)+
Positive Power Supply Current - Disabled (EL5371) EN pin tied to 4.8V
IS(OFF)-
Negative Power Supply Current - Disabled (EL5371)
PSRR
Power Supply Rejection Ratio
4.75
6.8
11
V
7.5
8.2
mA
1.7
10
µA
-200
-120
µA
VS from ±4.5V to ±5.5V (EL5171)
70
84
dB
VS from ±4.5V to ±5.5V (EL5371)
65
83
dB
ns
ENABLE (EL5371 ONLY)
tEN
Enable Time
215
tDS
Disable Time
0.95
VIH
EN Pin Voltage for Power-Up
VIL
EN Pin Voltage for Shutdown
IIH-EN
EN Pin Input Current High
At VEN = 5V
IIL-EN
EN Pin Input Current Low
At VEN = 0V
µs
VS+ 1.5
VS+ 0.5
V
122
-10
V
-8
130
µA
µA
Pin Descriptions
EL5171
EL5371
PIN NAME
PIN FUNCTION
1
FBP
Feedback from non-inverting output
2
IN+
Non-inverting input
3
REF
Reference input, sets common-mode output voltage
4
FBN
Feedback from inverting output
5
OUT-
Inverting output
6
VS+
Positive supply
7
VS-
Negative supply
8
OUT+
17, 21, 27
FBP3, FBP2, FBP1
2, 6, 10
INP1, INP2, INP3
4, 8, 12
REF1, REF2, REF3
3
Non-inverting output
Feedback from non-inverting output
Non-inverting inputs
Reference input, sets common-mode output voltage
FN7307.7
August 10, 2010
EL5171, EL5371
Pin Descriptions (Continued)
EL5171
EL5371
PIN NAME
3, 7, 11
INN1, INN2, INN3
16, 20, 26
FBN3, FBN2, FBN1
15, 19, 25
PIN FUNCTION
Inverting inputs, note that on EL5171, this pin is also the REF pin
Feedback from inverting output
OUT3B, OUT2B, OUT1B Inverting outputs
24
VSP
Positive supply
23
VSN
Negative supply
18, 22, 28
OUT3, OUT2, OUT1
1, 5, 9, 13
NC
No connects, grounded for best crosstalk performance
14
EN
ENABLE
4
Non-inverting outputs
FN7307.7
August 10, 2010
Connection Diagrams
RF1
CL1
5pF
-5V
INP
RG
REF
5
RS1
50Ω
RS1
50Ω
1 FBP
OUT 8
2 INP
VSN 7
3 REF
VSP 6
4 FBN
OUTB 5
RF3
OUT
RLD
1kΩ
OUTB
+5V
CL2
5pF
FIGURE 1. EL5171
+5V
INN1
REF1
INP2
INN2
REF2
INP3
INN3
REF3
RSP1
50Ω
RSN1
50Ω
RSR1
50Ω
RSP2
50Ω
RSN2
50Ω
RSR2
50Ω
RSP3
50Ω
RSN3
50Ω
RSR3
50Ω
1 NC
OUT1 28
2 INP1
FBP1 27
3 INN1
FBN1 26
4 REF1
OUT1B 25
5 NC
VSP 24
6 INP2
VSN 23
7 INN2
OUT2 22
8 REF2
FBP2 21
9 NC
FBN2 20
10 INP3
OUT2B 19
11 INN3
OUT3 18
12 REF3
FBP3 17
13 NC
FBn3 16
14 EN
OUT3B 15
RF
RG
FN7307.7
August 10, 2010
FIGURE 2. EL5371
RLD1
1kΩ
RF
RF
RG
RLD2
1kΩ
RF
RF
RG
-5V
ENABLE
EL5171, EL5371
INP1
RLD3
1kΩ
RF
CL1
5pF
CL1B
5pF
CL2
5pF
CL2B
5pF
CL3
5pF
CL3B
5pF
EL5171, EL5371
Typical Performance Curves
AV = 1, RLD = 1kΩ, CLD = 2.7pF
RLD = 1kΩ, CLD = 2.7pF
4
4
NORMALIZED MAGNITUDE (dB)
3
MAGNITUDE (dB)
2
1
0
VOP-P = 200mV
-1
-2
-3
VOP-P = 1VP-P
-4
-5
-6
1M
10M
100M
3
2
1
0
-1
AV = 1
-2
AV = 5
-3
-4
AV = 10
-5
-6
1M
1G
FIGURE 3. FREQUENCY RESPONSE
1G
AV = 1, RLD = 1kΩ
5
3
4
2
3
1
RLD = 1kΩ
0
RLD = 500Ω
-1
-2
RLD = 200Ω
MAGNITUDE (dB)
NORMALIZED GAIN (dB)
AV = 1, CLD = 2.7pF
CLD = 56pF
CLD = 34pF
2
CLD = 23pF
1
0
-1
CLD = 9pF
-2
CLD = 2.7pF
-3
-5
-4
-6
1M
10M
100M
-5
1M
1G
FREQUENCY (Hz)
10
9
9
NORMALIZED GAIN (dB)
8
RF = 1kΩ
RF = 500Ω
5
4
3
2
RF = 200Ω
1
0
1M
1G
AV = 2, RF = 1kΩ, CLD = 2.7pF
AV = 2, RLD = 1kΩ, CLD = 2.7pF
6
100M
FIGURE 6. FREQUENCY RESPONSE vs CLD
10
7
10M
FREQUENCY (Hz)
FIGURE 5. FREQUENCY RESPONSE vs RLD
NORMALIZED GAIN (dB)
100M
FIGURE 4. FREQUENCY RESPONSE FOR VARIOUS GAIN
4
-4
10M
FREQUENCY (Hz)
FREQUENCY (Hz)
-3
AV = 2
8
7
6
RLD = 1kΩ
5
4
RLD = 500Ω
3
2
RLD = 200Ω
1
10M
100M
FREQUENCY (Hz)
FIGURE 7. FREQUENCY RESPONSE
6
400M
0
1M
10M
100M
400M
FREQUENCY (Hz)
FIGURE 8. FREQUENCY RESPONSE vs RLD
FN7307.7
August 10, 2010
EL5171, EL5371
Typical Performance Curves
(Continued)
5
100
4
2
IMPEDANCE (Ω)
MAGNITUDE (dB)
3
1
0
-1
-2
10
1
-3
-4
-5
100k
1M
10M
0.1
10k
100M
100k
FREQUENCY (Hz)
0
100
-10
90
-20
80
100M
70
-30
-40
PSRR-
-50
PSRR+
-60
60
50
40
30
-70
20
-80
10
100k
10k
1M
10M
0
100k
100M
1M
FREQUENCY (Hz)
10M
100M
1G
FREQUENCY (Hz)
FIGURE 11. PSRR vs FREQUENCY
FIGURE 12. CMRR vs FREQUENCY
-30
1k
-40
-50
100
GAIN (dB)
VOLTAGE NOISE (nV/√Hz),
CURRENT NOISE (pA/√Hz)
10M
FIGURE 10. OUTPUT IMPEDANCE vs FREQUENCY
CMRR (dB)
PSRR (dB)
FIGURE 9. FREQUENCY RESPONSE - VREF
-90
1k
1M
FREQUENCY (Hz)
EN
10
CH1 <=> CH2, CH2 <=> CH3
-70
-80
100
1k
10k
100k
1M
10M
FREQUENCY (Hz)
FIGURE 13. VOLTAGE AND CURRENT NOISE vs FREQUENCY
7
CH1 <=> CH3
-90
IN
1
10
-60
-100
100k
1M
10M
100M
1G
FREQUENCY (Hz)
FIGURE 14. CHANNEL ISOLATION vs FREQUENCY
FN7307.7
August 10, 2010
EL5171, EL5371
Typical Performance Curves
(Continued)
VS = ±5V, AV = 1, RLD = 1kΩ
VS = ±5V, AV = 1, RLD = 1kΩ
-50
-50
-55
-55
-60
DISTORTION (dB)
DISTORTION (dB)
-60
-65
-70
HD3 (f = 20MHz)
-75
HD3 (f = 5MHz)
-80
-85
= 20M
HD2 (f
-90
Hz )
(f
HD2
-95
-100
1.0
1.5
2.0
2.5
3.0
=
4.0
z)
HD3 (f = 20MH
-70
-75
-80
HD2 (f = 5M
-85
z)
5M H
3.5
HD3 (f = 5MHz)
-65
HD2 (f = 20MHz)
-90
4.5
-95
1
5.0
2
3
4
VOP-P, DM (V)
5
6
7
8
9
10
VOP-P, DM (V)
FIGURE 15. HARMONIC DISTORTION vs DIFFERENTIAL
OUTPUT VOLTAGE
FIGURE 16. HARMONIC DISTORTION vs DIFFERENTIAL
OUTPUT VOLTAGE
VS = ±5V, AV = 2, VOP-P, DM = 2V
VS = ±5V, AV = 1, VOP-P, DM = 1V
-40
-50
-55
HD
-65
-70
-75
3
(f
HD
3
=
HD
-80
-85
20
M
2 (f
HD2
(f
-90
(f
=
5M
Hz
)
=2
HD3 (f = 20MHz)
-50
0M
H
DISTORTION (dB)
-60
DISTORTION (dB)
Hz)
Hz
)
z)
= 5M
Hz)
HD3 (f = 5MHz)
-60
-70
HD2 (f
-80
-90
= 20M H
z)
HD2 (f = 5MHz)
-95
-100
100
200
300
400
600
500
700
800
900 1000
-100
200
FIGURE 17. HARMONIC DISTORTION vs RLD
500
600
700
800
900
1000
FIGURE 18. HARMONIC DISTORTION vs RLD
VS = ±5V, RLD = 1kΩ, VOP-P, DM = 1V for AV = 1,
VOP-P, DM = 2V for AV = 2
HD3 (AV = 1)
-50
DISTORTION (dB)
400
RLD (Ω)
RLD (Ω)
-40
300
-60
3
HD
-70
(A V
)
=2
HD2 (AV =
HD2 (AV
2)
50mV/DIV
= 1)
-80
-90
-100
0
10
20
30
40
50
60
10ns/DIV
FREQUENCY (MHz)
FIGURE 19. HARMONIC DISTORTION vs FREQUENCY
8
FIGURE 20. SMALL SIGNAL TRANSIENT RESPONSE
FN7307.7
August 10, 2010
EL5171, EL5371
Typical Performance Curves
(Continued)
M = 100ns, CH1 = 500mV/DIV, CH2 = 5V/DIV
CH1
0.5V/DIV
CH2
100ns/DIV
10ns/DIV
FIGURE 21. LARGE SIGNAL TRANSIENT RESPONSE
FIGURE 22. ENABLED RESPONSE
JEDEC JESD51-3 LOW EFFECTIVE THERMAL
CONDUCTIVITY TEST BOARD
M = 200ns, CH1 = 500mV/DIV, CH2 = 5V/DIV
POWER DISSIPATION (W)
1.2
CH1
CH2
1.010W
1.0
QSOP28
θJA =+99°C/W
0.8
625mW
0.6
0.4
SO8
θJA = +160°C/W
0.2
0
200ns/DIV
0
25
50
75 85 100
125
150
AMBIENT TEMPERATURE (°C)
FIGURE 24. PACKAGE POWER DISSIPATION vs AMBIENT
TEMPERATURE
FIGURE 23. DISABLED RESPONSE
POWER DISSIPATION (W)
1.4
JEDEC JESD51-7 HIGH EFFECTIVE THERMAL
CONDUCTIVITY TEST BOARD
1.2
1.266W
1.0
909mW
QSOP28
θJA = +79°C/W
0.8
0.6
SO8
θJA = +110°C/W
0.4
0.2
0
0
25
50
75 85 100
125
150
AMBIENT TEMPERATURE (°C)
FIGURE 25. PACKAGE POWER DISSIPATION vs AMBIENT TEMPERATURE
9
FN7307.7
August 10, 2010
EL5171, EL5371
Simplified Schematic
VS+
R1
IN+
IN-
R3
R2
FBP
R4
R7
R8
FBN
VB1
OUT+
RCD
REF
RCD
VB2
CC
OUT-
R9
R10
CC
R5
R6
VS-
Description of Operation and Application
Information
Product Description
The EL5171 and EL5371 are wide bandwidth, low power
and single-ended to differential output amplifiers. The
EL5171 is a single channel differential amplifier. Since the
IN- pin and REF pin are tied together internally, the EL5171
can be used as a single-ended to differential converter. The
EL5371 is a triple channel differential amplifier. The EL5371
has a separate IN- pin and REF pin for each channel. It can
be used as a single/differential ended to differential
converter. The EL5171 and EL5371 are internally
compensated for closed loop gain of +1 or greater.
Connected in gain of 1 and driving a 1kΩ differential load,
the EL5171 and EL5371 have a -3dB bandwidth of 250MHz.
Driving a 200Ω differential load at gain of 2, the bandwidth is
about 30MHz. The EL5371 is available with a power-down
feature to reduce the power while the amplifier is disabled.
part of the common mode signal and also part of the differential
mode signal. For the true balance differential outputs, the REF
pin must be tied to the same bias level as the IN+ pin. For a ±5V
supply, just tie the REF pin to GND if the IN+ pin is biased at 0V
with a 50Ω or 75Ω termination resistor. For a single supply
application, if the IN+ is biased to half of the rail, the REF pin
should be biased to half of the rail also.
The gain setting for EL5171 is expressed in Equation 1:
R F1 + R F2⎞
⎛
V ODM = V IN + × ⎜ 1 + ----------------------------⎟
RG
⎝
⎠
2R F⎞
⎛
V ODM = V IN + × ⎜ 1 + -----------⎟
RG ⎠
⎝
(EQ. 1)
V OCM = V REF = 0V
Where:
• VREF = 0V
Input, Output, and Supply Voltage Range
• RF1 = RF2 = RF
The EL5171 and EL5371 have been designed to operate with
a single supply voltage of 5V to 10V or split supplies with its
total voltage from 5V to 10V. The amplifiers have an input
common mode voltage range from -4.5V to 3.4V for ±5V
supply. The differential mode input range (DMIR) between the
two inputs is from -2.3V to +2.3V. The input voltage range at
the REF pin is from -3.3V to 3.8V. If the input common mode
or differential mode signal is outside the above-specified
ranges, it will cause the output signal to become distorted.
The EL5371 has a separate IN- pin and REF pin. It can be
used as a single/differential ended to differential converter.
The voltage applied at REF pin can set the output common
mode voltage and the gain is one.
The output of the EL5171 and EL5371 can swing from -3.9V
to +3.9V at 1kΩ differential load at ±5V supply. As the load
resistance becomes lower, the output swing is reduced.
The gain setting for EL5371 is expressed in Equation 2:
2R F⎞
⎛
V ODM = ( V IN + – V IN - ) × ⎜ 1 + -----------⎟
RG ⎠
⎝
V OCM = V REF
R F1 + R F2⎞
⎛
V ODM = ( V IN + – V IN - ) × ⎜ 1 + ----------------------------⎟
RG
⎝
⎠
Differential and Common Mode Gain Settings
Where:
For EL5171, since the IN- pin and REF pin are bound together
as the REF pin in an 8 Ld package, the signal at the REF pin is
• RF1 = RF2 = RF
10
(EQ. 2)
FN7307.7
August 10, 2010
EL5171, EL5371
may have high capacitive loads without a back-termination
resistor. Again, a small series resistor at the output can help
to reduce peaking.
RF1
FBP
VIN+
VIN-
RG
VREF
Disable/Power-Down (for EL5371 only)
V O+
IN+
INREF
V O-
FBN
RF2
FIGURE 26.
Choice of Feedback Resistor and Gain Bandwidth
Product
For applications that require a gain of +1, no feedback resistor
is required. Just short the OUT+ pin to the FBP pin and the
OUT- pin to the FBN pin. For gains greater than +1, the
feedback resistor forms a pole with the parasitic capacitance
at the inverting input. As this pole becomes smaller, the
amplifier's phase margin is reduced. This causes ringing in
the time domain and peaking in the frequency domain.
Therefore, RF has some maximum value that should not be
exceeded for optimum performance. If a large value of RF
must be used, a small capacitor in the few Pico farad range in
parallel with RF can help to reduce the ringing and peaking at
the expense of reducing the bandwidth.
The bandwidth of the EL5171 and EL5371 depends on the
load and the feedback network. RF and RG appear in parallel
with the load for gains other than +1. As this combination gets
smaller, the bandwidth falls off. Consequently, RF also has a
minimum value that should not be exceeded for optimum
bandwidth performance. For gain of +1, RF = 0 is optimum.
For the gains other than +1, optimum response is obtained
with RF between 500Ω to 1kΩ.
The EL5171 and EL5371 have a gain bandwidth product of
100MHz for RLD = 1kΩ. For gains ≥5, their bandwidth can be
predicted by Equation 3:
(EQ. 3)
Gain × BW = 100MHz
Driving Capacitive Loads and Cables
The EL5371 can be disabled and its outputs placed in a high
impedance state. The turn-off time is about 0.95µs and the
turn-on time is about 215ns. When disabled, the amplifier's
supply current is reduced to 1.7µA for IS+ and 120µA for IStypically, thereby effectively eliminating the power
consumption. The amplifier's power-down can be controlled
by standard CMOS signal levels at the ENABLE pin. The
applied logic signal is relative to the VS+ pin. Letting the EN
pin float or applying a signal that is less than 1.5V below VS+
will enable the amplifier. The amplifier will be disabled when
the signal at the EN pin is above VS+ - 0.5V.
Output Drive Capability
The EL5171 and EL5371 have internal short circuit protection.
Its typical short circuit current is ±90mA for EL5171 and
±70mA for EL5371. If the output is shorted indefinitely, the
power dissipation could easily increase such that the part will
be destroyed. Maximum reliability is maintained if the output
current never exceeds ±60mA. This limit is set by the design
of the internal metal interconnections.
Power Dissipation
With the high output drive capability of the EL5171 and
EL5371, it is possible to exceed the +135°C absolute
maximum junction temperature under certain load current
conditions. Therefore, it is important to calculate the maximum
junction temperature for the application to determine if the
load conditions or package types need to be modified for the
amplifier to remain in the safe operating area.
The maximum power dissipation allowed in a package is
determined according to Equation 4:
T JMAX – T AMAX
PD MAX = --------------------------------------------Θ JA
Where:
• TJMAX = Maximum junction temperature
The EL5171 and EL5371 can drive 50pF differential
capacitor in parallel with 1kΩ differential load with less than
5dB of peaking at gain of +1. If less peaking is desired in
applications, a small series resistor (usually between 5Ω to
50Ω) can be placed in series with each output to eliminate
most peaking. However, this will reduce the gain slightly. If
the gain setting is greater than 1, the gain resistor RG can
then be chosen to make up for any gain loss, which may be
created by the additional series resistor at the output.
• TAMAX = Maximum ambient temperature
When used as a cable driver, double termination is always
recommended for reflection-free performance. For those
applications, a back-termination series resistor at the
amplifier's output will isolate the amplifier from the cable and
allow extensive capacitive drive. However, other applications
Where:
11
(EQ. 4)
• θJA = Thermal resistance of the package
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
as represented in Equation 5:
ΔV O⎞
⎛
PD = i × ⎜ V S × I SMAX + V S × ------------⎟
R LD ⎠
⎝
(EQ. 5)
• VS = Total supply voltage
• ISMAX = Maximum quiescent supply current per channel
FN7307.7
August 10, 2010
EL5171, EL5371
• ΔVO = Maximum differential output voltage of the
application
to GND will suffice. This same capacitor combination should
be placed at each supply pin to ground if split supplies are to
be used. In this case, the VS- pin becomes the negative
supply rail.
• RLD = Differential load resistance
• ILOAD = Load current
• i = Number of channels
By setting the two PDMAX equations equal to each other, we
can solve the output current and RLD to avoid the device
overheat.
Power Supply Bypassing and Printed Circuit
Board Layout
As with any high frequency device, a good printed circuit
board layout is necessary for optimum performance. Lead
lengths should be as sort as possible. The power supply pin
must be well bypassed to reduce the risk of oscillation. For
normal single supply operation, where the VS- pin is
connected to the ground plane, a single 4.7µF tantalum
capacitor in parallel with a 0.1µF ceramic capacitor from VS+
For good AC performance, parasitic capacitance should be
kept to a minimum. Use of wire wound resistors should be
avoided because of their additional series inductance. Use
of sockets should also be avoided, if possible. Sockets add
parasitic inductance and capacitance that can result in
compromised performance. Minimizing parasitic capacitance
at the amplifier's inverting input pin is very important. The
feedback resistor should be placed very close to the
inverting input pin. Strip line design techniques are
recommended for the signal traces.
As the signal is transmitted through a cable, the high frequency
signal will be attenuated. One way to compensate this loss is to
boost the high frequency gain at the receiver side.
Typical Applications
RF
FBP
50
TWISTED PAIR
IN+
IN+
RT
RG
INREF
EL5171/
EL5371
50
IN-
ZO = 100Ω
FBN
EL5172/
EL5372
VO
REF
RF
RFR
RGR
FIGURE 27. TWISTED PAIR CABLE RECEIVER
RF
GAIN
(dB)
FBP
RT
75
RGC
VO+
IN+
RG
IN-
CL
REF
VO-
FBN
fL
RF
2R F
DC Gain = 1 + ----------RG
1
f L ≅ ------------------------2πR G C C
2R F
( HF )Gain = 1 + -------------------------R G || R GC
1
f H ≅ ----------------------------2πR GC C C
fH
FREQUENCY
FIGURE 28. TRANSMIT EQUALIZER
12
FN7307.7
August 10, 2010
EL5171, EL5371
Small Outline Package Family (SO)
A
D
h X 45°
(N/2)+1
N
A
PIN #1
I.D. MARK
E1
E
c
SEE DETAIL “X”
1
(N/2)
B
L1
0.010 M C A B
e
H
C
A2
GAUGE
PLANE
SEATING
PLANE
A1
0.004 C
0.010 M C A B
L
b
0.010
4° ±4°
DETAIL X
MDP0027
SMALL OUTLINE PACKAGE FAMILY (SO)
INCHES
SYMBOL
SO-14
SO16 (0.300”)
(SOL-16)
SO20
(SOL-20)
SO24
(SOL-24)
SO28
(SOL-28)
TOLERANCE
NOTES
A
0.068
0.068
0.068
0.104
0.104
0.104
0.104
MAX
-
A1
0.006
0.006
0.006
0.007
0.007
0.007
0.007
±0.003
-
A2
0.057
0.057
0.057
0.092
0.092
0.092
0.092
±0.002
-
b
0.017
0.017
0.017
0.017
0.017
0.017
0.017
±0.003
-
c
0.009
0.009
0.009
0.011
0.011
0.011
0.011
±0.001
-
D
0.193
0.341
0.390
0.406
0.504
0.606
0.704
±0.004
1, 3
E
0.236
0.236
0.236
0.406
0.406
0.406
0.406
±0.008
-
E1
0.154
0.154
0.154
0.295
0.295
0.295
0.295
±0.004
2, 3
e
0.050
0.050
0.050
0.050
0.050
0.050
0.050
Basic
-
L
0.025
0.025
0.025
0.030
0.030
0.030
0.030
±0.009
-
L1
0.041
0.041
0.041
0.056
0.056
0.056
0.056
Basic
-
h
0.013
0.013
0.013
0.020
0.020
0.020
0.020
Reference
-
16
20
24
28
Reference
-
N
SO-8
SO16
(0.150”)
8
14
16
Rev. M 2/07
NOTES:
1. Plastic or metal protrusions of 0.006” maximum per side are not included.
2. Plastic interlead protrusions of 0.010” maximum per side are not included.
3. Dimensions “D” and “E1” are measured at Datum Plane “H”.
4. Dimensioning and tolerancing per ASME Y14.5M-1994
13
FN7307.7
August 10, 2010
EL5171, EL5371
Quarter Size Outline Plastic Packages Family (QSOP)
MDP0040
A
QUARTER SIZE OUTLINE PLASTIC PACKAGES FAMILY
D
(N/2)+1
N
INCHES
SYMBOL QSOP16 QSOP24 QSOP28 TOLERANCE NOTES
E
PIN #1
I.D. MARK
E1
1
(N/2)
B
0.010
C A B
e
H
C
SEATING
PLANE
0.007
0.004 C
b
C A B
A
0.068
0.068
0.068
Max.
-
A1
0.006
0.006
0.006
±0.002
-
A2
0.056
0.056
0.056
±0.004
-
b
0.010
0.010
0.010
±0.002
-
c
0.008
0.008
0.008
±0.001
-
D
0.193
0.341
0.390
±0.004
1, 3
E
0.236
0.236
0.236
±0.008
-
E1
0.154
0.154
0.154
±0.004
2, 3
e
0.025
0.025
0.025
Basic
-
L
0.025
0.025
0.025
±0.009
-
L1
0.041
0.041
0.041
Basic
-
N
16
24
28
Reference
Rev. F 2/07
NOTES:
L1
A
1. Plastic or metal protrusions of 0.006” maximum per side are not
included.
2. Plastic interlead protrusions of 0.010” maximum per side are not
included.
c
SEE DETAIL "X"
3. Dimensions “D” and “E1” are measured at Datum Plane “H”.
4. Dimensioning and tolerancing per ASME Y14.5M-1994.
0.010
A2
GAUGE
PLANE
L
A1
4°±4°
DETAIL X
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14
FN7307.7
August 10, 2010