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LM7171
SNOS760C –MAY 1999–REVISED SEPTEMBER 2014
LM7171 Very High Speed, High Output Current, Voltage Feedback Amplifier
1 Features 3 Description
The LM7171 is a high speed voltage feedback
1• (Typical Unless Otherwise Noted) amplifier that has the slewing characteristic of a
• Easy-to-Use Voltage Feedback Topology current feedback amplifier, yet it can be used in all
• Very High Slew Rate: 4100 V/μstraditional voltage feedback amplifier configurations.
The LM7171 is stable for gains as low as +2 or −1. It
• Wide Unity-Gain Bandwidth: 200 MHz provides a very high slew rate at 4100V/μs and a
•−3 dB Frequency @ AV= +2: 220 MHz wide unity-gain bandwidth of 200 MHz while
• Low Supply Current: 6.5 mA consuming only 6.5 mA of supply current. It is ideal
for video and high speed signal processing
• High Open Loop Gain: 85 dB applications such as HDSL and pulse amplifiers. With
• High Output Current: 100 mA 100 mA output current, the LM7171 can be used for
• Differential Gain and Phase: 0.01%, 0.02° video distribution, as a transformer driver or as a
• Specified for ±15V and ±5V Operation laser diode driver.
Operation on ±15 V power supplies allows for large
2 Applications signal swings and provides greater dynamic range
• HDSL and ADSL Drivers and signal-to-noise ratio. The LM7171 offers low
SFDR and THD, ideal for ADC/DAC systems. In
• Multimedia Broadcast Systems addition, the LM7171 is specified for ±5 V operation
• Professional Video Cameras for portable applications.
• Video Amplifiers The LM7171 is built on TI's advanced VIP™ III
• Copiers/Scanners/Fax (Vertically integrated PNP) complementary bipolar
• HDTV Amplifiers process.
• Pulse Amplifiers and Peak Detectors Device Information(1)
• CATV/Fiber Optics Signal Processing PART NUMBER PACKAGE BODY SIZE (NOM)
LM7171 SOIC (8) 4.90 mm × 3.91 mm
LM7171 PDIP (8) 9.81 mm × 6.35 mm
(1) For all available packages, see the orderable addendum at
the end of the datasheet.
Large Signal Pulse Response
Simplified Schematic Diagram AV= +2, VS= ±15V
Note: M1 and M2 are current mirrors.
1
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.
LM7171
SNOS760C –MAY 1999–REVISED SEPTEMBER 2014
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Table of Contents
7.2 Circuit Operation..................................................... 18
1 Features.................................................................. 17.3 Slew Rate Characteristic......................................... 18
2 Applications ........................................................... 17.4 Slew Rate Limitation ............................................... 18
3 Description............................................................. 17.5 Compensation For Input Capacitance .................... 19
4 Revision History..................................................... 27.6 Application Circuit ................................................... 19
5 Pin Configuration and Functions......................... 38 Power Supply Recommendations...................... 21
6 Specifications......................................................... 48.1 Power Supply Bypassing ........................................ 21
6.1 Absolute Maximum Ratings ...................................... 48.2 Termination............................................................. 22
6.2 Handling Ratings....................................................... 48.3 Driving Capacitive Loads ........................................ 23
6.3 Recommended Operating Conditions....................... 48.4 Power Dissipation ................................................... 24
6.4 Thermal Information.................................................. 49 Layout................................................................... 25
6.5 ±15V DC Electrical Characteristics .......................... 59.1 Layout Guidelines ................................................... 25
6.6 ±15V AC Electrical Characteristics .......................... 610 Device and Documentation Support................. 26
6.7 ±5V DC Electrical Characteristics ............................ 710.1 Trademarks........................................................... 26
6.8 ±5V AC Electrical Characteristics ............................ 810.2 Electrostatic Discharge Caution............................ 26
6.9 Typical Performance Characteristics ........................ 910.3 Glossary................................................................ 26
7 Application and Implementation ........................ 18 11 Mechanical, Packaging, and Orderable
7.1 Application Information............................................ 18 Information ........................................................... 26
4 Revision History
NOTE: Page numbers for previous revisions may differ from page numbers in the current version.
Changes from Revision B (March 2013) to Revision C Page
• Changed data sheet flow and layout to conform with new TI standards. Added the following sections: Device
Information Table, Application and Implementation; Layout; Device and Documentation Support; Mechanical,
Packaging, and Ordering Information .................................................................................................................................... 1
• Changed "Junction Temperature Range" to " Operating Temperature Range" and deleted TJ............................................ 4
• Deleted TJ= 25°C for Electrical Characteristics tables.......................................................................................................... 5
Changes from Revision A (March 2013) to Revision B Page
• Changed layout of National Data Sheet to TI format ........................................................................................................... 20
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5 Pin Configuration and Functions
8-Pin
Package D
(Top View)
Pin Functions
PIN I/O DESCRIPTION
NAME NO.
N/C 1 – No Connection
-IN 2 I Inverting Power Supply
+IN 3 I Non-inverting Power Supply
V- 4 I Supply Voltage
N/C 5 – No Connection
OUTPUT 6 O Output
V+ 7 I Supply Voltage
N/C 8 – No Connection
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6 Specifications
6.1 Absolute Maximum Ratings
over operating free-air temperature range (unless otherwise noted) (1)
MIN MAX UNIT
Supply Voltage (V+–V−) 36 V
Differential Input Voltage (2) ±10 V
Output Short Circuit to Ground (3) Continuous
Maximum Junction Temperature (4) 150 °C
(1) Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings
only, which do not imply functional operation of the device at these or any other conditions beyond those indicated under Recommended
Operating Conditions. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
(2) Input differential voltage is applied at VS= ±15V.
(3) Applies to both single-supply and split-supply operation. Continuous short circuit operation at elevated ambient temperature can result in
exceeding the maximum allowed junction temperature of 150°C.
(4) The maximum power dissipation is a function of TJ(MAX), RθJA, and TA. The maximum allowable power dissipation at any ambient
temperature is PD= (TJ(MAX)–TA)/RθJA. All numbers apply for packages soldered directly into a PC board.
6.2 Handling Ratings MIN MAX UNIT
Tstg Storage temperature range −65 +150 °C
Human body model (HBM), per ANSI/ESDA/JEDEC JS-001, all 2500
V(ESD) Electrostatic discharge(1) V
pins(2)
(1) Human body model, 1.5 kΩin series with 100 pF.
(2) JEDEC document JEP155 states that 2500-V HBM allows safe manufacturing with a standard ESD control process.
6.3 Recommended Operating Conditions(1)
over operating free-air temperature range (unless otherwise noted) MIN TYP MAX UNIT
Supply Voltage 5.5V ≤VS≤36 V
Operating Temperature Range: LM7171AI, LM7171BI −40 +85 °C
(1) Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for
which the device is intended to be functional, but specific performance is not specified. For ensured specifications and the test
conditions, see the Electrical Characteristics.
6.4 Thermal Information P (PDIP) D (SOIC)
THERMAL METRIC(1) UNIT
8 PINS 8 PINS
RθJA Junction-to-ambient thermal resistance 108° 172° °C/W
(1) For more information about traditional and new thermal metrics, see the IC Package Thermal Metrics application report, SPRA953.
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6.5 ±15V DC Electrical Characteristics
Unless otherwise noted, all limits are specified for V+= +15 V, V−= –15 V, VCM = 0V, and RL= 1 kΩ.Boldface limits apply at
the temperature extremes
PARAMETER TEST CONDITIONS TYP LM7171AI LM7171BI UNIT
(1) LIMIT(2) LIMIT(2)
VOS Input Offset Voltage 0.2 1 3 mV
4 7 max
TC VOS Input Offset Voltage Average 35 μV/°C
Drift
IBInput Bias Current 2.7 10 10 μA
12 12 max
IOS Input Offset Current 0.1 4 4 μA
6 6 max
RIN Input Resistance Common Mode 40 MΩ
Differential Mode 3.3
ROOpen Loop Output 15 Ω
Resistance
CMRR Common Mode Rejection VCM = ±10V 105 85 75 dB
Ratio 80 70 min
PSRR Power Supply Rejection Ratio VS= ±15V to ±5V 90 85 75 dB
80 70 min
VCM Input Common-Mode Voltage CMRR > 60 dB ±13.35 V
Range
AVLarge Signal Voltage Gain (3) RL= 1 kΩ85 80 75 dB
75 70 min
RL= 100Ω81 75 70 dB
70 66 min
VOOutput Swing RL= 1 kΩ13.3 13 13 V
12.7 12.7 min
−13.2 −13 −13 V
−12.7 −12.7 max
RL= 100Ω11.8 10.5 10.5 V
9.5 9.5 min
−10.5 −9.5 −9.5 V
−9−9max
Output Current (Open Loop) Sourcing, RL= 100Ω118 105 105 mA
(4) 95 95 min
Sinking, RL= 100Ω105 95 95 mA
90 90 max
Output Current (in Linear Sourcing, RL= 100Ω100 mA
Region) Sinking, RL= 100Ω100
ISC Output Short Circuit Current Sourcing 140 mA
Sinking 135
ISSupply Current 6.5 8.5 8.5 mA
9.5 9.5 max
(1) Typical values represent the most likely parametric norm.
(2) All limits are specified by testing or statistical analysis.
(3) Large signal voltage gain is the total output swing divided by the input signal required to produce that swing. For VS= ±15V, VOUT =
±5V. For VS= ±5V, VOUT = ±1V.
(4) The open loop output current is specified, by the measurement of the open loop output voltage swing, using 100Ωoutput load.
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6.6 ±15V AC Electrical Characteristics
Unless otherwise noted, all limits are specified for V+= +15V, V−=−15V, VCM = 0V, and RL= 1 kΩ.
PARAMETER CONDITIONS LM7171AI LM7171BI UNIT
TYP(1) LIMIT(2) LIMIT(2)
SR Slew Rate (3) AV= +2, VIN = 13 VPP 4100 V/μs
AV= +2, VIN = 10 VPP 3100
Unity-Gain Bandwidth 200 MHz
−3 dB Frequency AV= +2 220 MHz
φmPhase Margin 50 Deg
tsSettling Time (0.1%) AV=−1, VO= ±5V 42 ns
RL= 500Ω
tpPropagation Delay AV=−2, VIN = ±5V, 5 ns
RL= 500Ω
ADDifferential Gain (4) 0.01%
φDDifferential Phase (4) 0.02 Deg
Second Harmonic Distortion(5) fIN = 10 kHz −110 dBc
fIN = 5 MHz −75 dBc
Third Harmonic Distortion(5) fIN = 10 kHz −115 dBc
fIN = 5 MHz −55 dBc
enInput-Referred Voltage Noise f = 10 kHz 14 nV/√Hz
inInput-Referred Current Noise f = 10 kHz 1.5 pA/√Hz
(1) Typical values represent the most likely parametric norm.
(2) All limits are specified by testing or statistical analysis.
(3) Slew Rate is the average of the raising and falling slew rates.
(4) Differential gain and phase are measured with AV= +2, VIN = 1 VPP at 3.58 MHz and both input and output 75Ωterminated.
(5) Harmonics are measured with VIN = 1 VPP, AV= +2 and RL= 100Ω.
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6.7 ±5V DC Electrical Characteristics
Unless otherwise noted, all limits are specified for V+= +5V, V−=−5V, VCM = 0V, and RL= 1 kΩ.Boldface limits apply at the
temperature extremes
PARAMETER TEST CONDITIONS LM7171AI LM7171BI UNIT
TYP(1) LIMIT(2) LIMIT(2)
VOS Input Offset Voltage 0.3 1.5 3.5 mV
4 7 max
TC VOS Input Offset Voltage Average 35 μV/°C
Drift
IBInput Bias Current 3.3 10 10 μA
12 12 max
IOS Input Offset Current 0.1 4 4 μA
6 6 max
RIN Input Resistance Common Mode 40 MΩ
Differential Mode 3.3
ROOutput Resistance 15 Ω
CMRR Common Mode Rejection VCM = ±2.5V 104 80 70 dB
Ratio 75 65 min
PSRR Power Supply Rejection Ratio VS= ±15V to ±5V 90 85 75 dB
80 70 min
VCM Input Common-Mode Voltage CMRR > 60 dB ±3.2 V
Range
AVLarge Signal Voltage Gain (3) RL= 1 kΩ78 75 70 dB
70 65 min
RL= 100Ω76 72 68 dB
67 63 min
VOOutput Swing RL= 1 kΩ3.4 3.2 3.2 V
3 3 min
−3.4 −3.2 −3.2 V
−3−3max
RL= 100Ω3.1 2.9 2.9 V
2.8 2.8 min
−3.0 −2.9 −2.9 V
−2.8 −2.8 max
Output Current (Open Loop) Sourcing, RL= 100Ω31 29 29 mA
(4) 28 28 min
Sinking, RL= 100Ω30 29 29 mA
28 28 max
ISC Output Short Circuit Current Sourcing 135 mA
Sinking 100
ISSupply Current 6.2 8 8 mA
9 9 max
(1) Typical values represent the most likely parametric norm.
(2) All limits are specified by testing or statistical analysis.
(3) Large signal voltage gain is the total output swing divided by the input signal required to produce that swing. For VS= ±15V, VOUT =
±5V. For VS= ±5V, VOUT = ±1V.
(4) The open loop output current is specified, by the measurement of the open loop output voltage swing, using 100Ωoutput load.
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6.8 ±5V AC Electrical Characteristics
Unless otherwise noted, all limits are specified for V+= +5V, V−=−5V, VCM = 0V, and RL= 1 kΩ.
PARAMETER TEST CONDITIONS LM7171AI LM7171BI UNIT
TYP(1) LIMIT(2) LIMIT(2)
SR Slew Rate (3) AV= +2, VIN = 3.5 VPP 950 V/μs
Unity-Gain Bandwidth 125 MHz
−3 dB Frequency AV= +2 140 MHz
φmPhase Margin 57 Deg
tsSettling Time (0.1%) AV=−1, VO= ±1V, 56 ns
RL= 500Ω
tpPropagation Delay AV=−2, VIN = ±1V, 6 ns
RL= 500Ω
ADDifferential Gain (4) 0.02%
φDDifferential Phase (5) 0.03 Deg
Second Harmonic Distortion(6) fIN = 10 kHz −102 dBc
fIN = 5 MHz −70 dBc
Third Harmonic Distortion(6) fIN = 10 kHz −110 dBc
fIN = 5 MHz −51 dBc
enInput-Referred Voltage Noise f = 10 kHz 14 nV/√Hz
inInput-Referred Current Noise f = 10 kHz 1.8 pA/√Hz
(1) Typical values represent the most likely parametric norm.
(2) All limits are specified by testing or statistical analysis.
(3) Slew Rate is the average of the raising and falling slew rates.
(4) Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for
which the device is intended to be functional, but specific performance is not specified. For ensured specifications and the test
conditions, see the Electrical Characteristics.
(5) Differential gain and phase are measured with AV= +2, VIN = 1 VPP at 3.58 MHz and both input and output 75Ωterminated.
(6) Harmonics are measured with VIN = 1 VPP, AV= +2 and RL= 100Ω.
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6.9 Typical Performance Characteristics
unless otherwise noted, TA= 25°C
Figure 1. Supply Current vs. Supply Voltage Figure 2. Supply Current vs. Temperature
Figure 4. Input Bias Current vs. Temperature
Figure 3. Input Offset Voltage vs. Temperature
Figure 5. Short Circuit Current vs. Temperature (Sourcing) Figure 6. Short Circuit Current vs. Temperature (Sinking)
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Typical Performance Characteristics (continued)
unless otherwise noted, TA= 25°C
Figure 7. Output Voltage vs. Output Current Figure 8. Output Voltage vs. Output Current
Figure 9. CMRR vs. Frequency Figure 10. PSRR vs. Frequency
Figure 11. PSRR vs. Frequency Figure 12. Open Loop Frequency Response
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Typical Performance Characteristics (continued)
unless otherwise noted, TA= 25°C
Figure 14. Gain-Bandwidth Product vs. Supply Voltage
Figure 13. Open Loop Frequency Response
Figure 16. Large Signal Voltage Gain vs. Load
Figure 15. Gain-Bandwidth Product vs. Load Capacitance
Figure 17. Large Signal Voltage Gain vs. Load Figure 18. Input Voltage Noise vs. Frequency
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Typical Performance Characteristics (continued)
unless otherwise noted, TA= 25°C
Figure 19. Input Voltage Noise vs. Frequency Figure 20. Input Current Noise vs. Frequency
Figure 22. Slew Rate vs. Supply Voltage
Figure 21. Input Current Noise vs. Frequency
Figure 23. Slew Rate vs. Input Voltage Figure 24. Slew Rate vs. Load Capacitance
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Typical Performance Characteristics (continued)
unless otherwise noted, TA= 25°C
Figure 25. Open Loop Output Impedance vs. Frequency Figure 26. Open Loop Output Impedance vs Frequency
Figure 27. Large Signal Pulse Response AV=−1, VS= ±15V Figure 28. Large Signal Pulse Response AV=−1, VS= ±5V
Figure 29. Large Signal Pulse Response AV= +2, VS= ±15V Figure 30. Large Signal Pulse Response AV= +2, VS= ±5V
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Typical Performance Characteristics (continued)
unless otherwise noted, TA= 25°C
Figure 31. Small Signal Pulse Response AV=−1, VS= ±15V Figure 32. Small Signal Pulse Response AV=−1, VS= ±5V
Figure 33. Small Signal Pulse Response AV= +2, VS= ±15V Figure 34. Small Signal Pulse Response AV= +2, VS= ±5V
Figure 36. Closed Loop Frequency Response vs. Capacitive
Figure 35. Closed Loop Frequency Response vs. Supply Load (AV= +2)
Voltage (AV= +2)
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Typical Performance Characteristics (continued)
unless otherwise noted, TA= 25°C
Figure 37. Closed Loop Frequency Response vs. Capacitive Figure 38. Closed Loop Frequency Response vs. Input
Load (AV= +2) Signal Level (AV= +2)
Figure 39. Closed Loop Frequency Response vs. Input Figure 40. Closed Loop Frequency Response vs. Input
Signal Level (AV= +2) Signal Level (AV= +2)
Figure 42. Closed Loop Frequency Response vs. Input
Figure 41. Closed Loop Frequency Response vs. Input Signal Level (AV= +4)
Signal Level (AV= +2)
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Typical Performance Characteristics (continued)
unless otherwise noted, TA= 25°C
Figure 43. Closed Loop Frequency Response vs. Input Figure 44. Closed Loop Frequency Response vs. Input
Signal Level (AV= +4) Signal Level (AV= +4)
Figure 46. Total Harmonic Distortion vs. Frequency (1)
Figure 45. Closed Loop Frequency Response vs. Input
Signal Level (AV= +4)
Figure 48. Undistorted Output Swing vs. Frequency
Figure 47. Total Harmonic Distortion vs. Frequency (1)
(1) The THD measurement at low frequency is limited by the test instrument.
(1) The THD measurement at low frequency is limited by the test instrument.
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Typical Performance Characteristics (continued)
unless otherwise noted, TA= 25°C
Figure 49. Undistorted Output Swing vs. Frequency Figure 50. Undistorted Output Swing vs. Frequency
Figure 51. Harmonic Distortion vs. Frequency (1) Figure 52. Harmonic Distortion vs. Frequency (1)
Figure 53. Maximum Power Dissipation vs. Ambient Temperature
(1) The THD measurement at low frequency is limited by the test instrument.
(1) The THD measurement at low frequency is limited by the test instrument.
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7 Application and Implementation
7.1 Application Information
The LM7171 is a very high speed, voltage feedback amplifier. It consumes only 6.5 mA supply current while
providing a unity-gain bandwidth of 200 MHz and a slew rate of 4100V/μs. It also has other great features such
as low differential gain and phase and high output current.
The LM7171 is a true voltage feedback amplifier. Unlike current feedback amplifiers (CFAs) with a low inverting
input impedance and a high non-inverting input impedance, both inputs of voltage feedback amplifiers (VFAs)
have high impedance nodes. The low impedance inverting input in CFAs and a feedback capacitor create an
additional pole that will lead to instability. As a result, CFAs cannot be used in traditional op amp circuits such as
photodiode amplifiers, I-to-V converters and integrators where a feedback capacitor is required.
7.2 Circuit Operation
The class AB input stage in LM7171 is fully symmetrical and has a similar slewing characteristic to the current
feedback amplifiers. In the LM7171 Simplified Schematic, Q1 through Q4 form the equivalent of the current
feedback input buffer, REthe equivalent of the feedback resistor, and stage A buffers the inverting input. The
triple-buffered output stage isolates the gain stage from the load to provide low output impedance.
7.3 Slew Rate Characteristic
The slew rate of LM7171 is determined by the current available to charge and discharge an internal high
impedance node capacitor. This current is the differential input voltage divided by the total degeneration resistor
RE. Therefore, the slew rate is proportional to the input voltage level, and the higher slew rates are achievable in
the lower gain configurations. A curve of slew rate versus input voltage level is provided in Typical Performance
Characteristics
When a very fast large signal pulse is applied to the input of an amplifier, some overshoot or undershoot occurs.
By placing an external resistor such as 1 kΩin series with the input of LM7171, the bandwidth is reduced to help
lower the overshoot.
7.4 Slew Rate Limitation
If the amplifier's input signal has too large of an amplitude at too high of a frequency, the amplifier is said to be
slew rate limited; this can cause ringing in time domain and peaking in frequency domain at the output of the
amplifier.
In Typical Performance Characteristics, there are several curves of AV= +2 and AV= +4 versus input signal
levels. For the AV= +4 curves, no peaking is present and the LM7171 responds identically to the different input
signal levels of 30 mV, 100 mV and 300 mV.
For the AV= +2 curves, with slight peaking occurs. This peaking at high frequency (>100 MHz) is caused by a
large input signal at high enough frequency that exceeds the amplifier's slew rate. The peaking in frequency
response does not limit the pulse response in time domain, and the LM7171 is stable with noise gain of ≥+2.
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7.5 Compensation For Input Capacitance
The combination of an amplifier's input capacitance with the gain setting resistors adds a pole that can cause
peaking or oscillation. To solve this problem, a feedback capacitor with a value
CF> (RG× CIN)/RF(1)
can be used to cancel that pole. For LM7171, a feedback capacitor of 2 pF is recommended. Figure 54 illustrates
the compensation circuit.
Figure 54. Compensating for Input Capacitance
7.6 Application Circuit
Figure 55. Fast Instrumentation Amplifier
Figure 56. Multivibrator
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8 Power Supply Recommendations
8.1 Power Supply Bypassing
Bypassing the power supply is necessary to maintain low power supply impedance across frequency. Both
positive and negative power supplies should be bypassed individually by placing 0.01 μF ceramic capacitors
directly to power supply pins and 2.2 μF tantalum capacitors close to the power supply pins.
Figure 59. Power Supply Bypassing
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8.2 Termination
In high frequency applications, reflections occur if signals are not properly terminated. Figure 60 shows a
properly terminated signal while Figure 61 shows an improperly terminated signal.
Figure 60. Properly Terminated Signal
Figure 61. Improperly Terminated Signal
To minimize reflection, coaxial cable with matching characteristic impedance to the signal source should be
used. The other end of the cable should be terminated with the same value terminator or resistor. For the
commonly used cables, RG59 has 75Ωcharacteristic impedance, and RG58 has 50Ωcharacteristic impedance.
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8.3 Driving Capacitive Loads
Amplifiers driving capacitive loads can oscillate or have ringing at the output. To eliminate oscillation or reduce
ringing, an isolation resistor can be placed as shown in Figure 62. The combination of the isolation resistor and
the load capacitor forms a pole to increase stability by adding more phase margin to the overall system. The
desired performance depends on the value of the isolation resistor; the bigger the isolation resistor, the more
damped the pulse response becomes. For LM7171, a 50Ωisolation resistor is recommended for initial
evaluation. Figure 63 shows the LM7171 driving a 150 pF load with the 50Ωisolation resistor.
Figure 62. Isolation Resistor Used
to Drive Capacitive Load
Figure 63. The LM7171 Driving a 150 pF Load
with a 50 ΩIsolation Resistor
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8.4 Power Dissipation
The maximum power allowed to dissipate in a device is defined as:
PD= (TJ(MAX) −TA)/θJA
where
• PD is the power dissipation in a device
• TJ(max) is the maximum junction temperature
• TAis the ambient temperature
• RθJA is the thermal resistance of a particular package
• (2)
For example, for the LM7171 in a SOIC-8 package, the maximum power dissipation at 25°C ambient
temperature is 730 mW.
Thermal resistance, R θJA, depends on parameters such as die size, package size and package material. The
smaller the die size and package, the higher RθJA becomes. The 8-pin DIP package has a lower thermal
resistance (108°C/W) than that of 8-pin SOIC (172°C/W). Therefore, for higher dissipation capability, use an 8-
pin DIP package.
The total power dissipated in a device can be calculated as:
PD= PQ+ PL
where
• PQis the quiescent power dissipated in a device with no load connected at the output. PLis the power
dissipated in the device with a load connected at the output; it is not the power dissipated by the load.
Furthermore,
• PQis the supply current × total supply voltage with no load
• PLis the output current × (voltage difference between supply voltage and output voltage of the same side of
supply voltage) (3)
For example, the total power dissipated by the LM7171 with VS= ±15V and output voltage of 10V into 1 kΩis
PD= PQ+ PL(4)
= (6.5 mA) × (30V) + (10 mA) × (15V −10V) (5)
= 195 mW + 50 mW (6)
= 245 mW (7)
24 Submit Documentation Feedback Copyright © 1999–2014, Texas Instruments Incorporated
Product Folder Links: LM7171
LM7171
www.ti.com
SNOS760C –MAY 1999–REVISED SEPTEMBER 2014
9 Layout
9.1 Layout Guidelines
9.1.1 Printed Circuit Board and High Speed Op Amps
There are many things to consider when designing PC boards for high speed op amps. Without proper caution, it
is very easy to have excessive ringing, oscillation and other degraded AC performance in high speed circuits. As
a rule, the signal traces should be short and wide to provide low inductance and low impedance paths. Any
unused board space needs to be grounded to reduce stray signal pickup. Critical components should also be
grounded at a common point to eliminate voltage drop. Sockets add capacitance to the board and can affect high
frequency performance. It is better to solder the amplifier directly into the PC board without using any socket.
9.1.2 Using Probes
Active (FET) probes are ideal for taking high frequency measurements because they have wide bandwidth, high
input impedance and low input capacitance. However, the probe ground leads provide a long ground loop that
will produce errors in measurement. Instead, the probes can be grounded directly by removing the ground leads
and probe jackets and using scope probe jacks.
9.1.3 Component Selection and Feedback Resistor
It is important in high speed applications to keep all component leads short. For discrete components, choose
carbon composition-type resistors and mica-type capacitors. Surface mount components are preferred over
discrete components for minimum inductive effect.
Large values of feedback resistors can couple with parasitic capacitance and cause undesirable effects such as
ringing or oscillation in high speed amplifiers. For LM7171, a feedback resistor of 510Ωgives optimal
performance.
Copyright © 1999–2014, Texas Instruments Incorporated Submit Documentation Feedback 25
Product Folder Links: LM7171
LM7171
SNOS760C –MAY 1999–REVISED SEPTEMBER 2014
www.ti.com
10 Device and Documentation Support
10.1 Trademarks
VIP is a trademark of Texas Instruments.
All other trademarks are the property of their respective owners.
10.2 Electrostatic Discharge Caution
These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam
during storage or handling to prevent electrostatic damage to the MOS gates.
10.3 Glossary
SLYZ022 —TI Glossary.
This glossary lists and explains terms, acronyms, and definitions.
11 Mechanical, Packaging, and Orderable Information
The following pages include mechanical, packaging, and orderable information. This information is the most
current data available for the designated devices. This data is subject to change without notice and revision of
this document. For browser-based versions of this data sheet, refer to the left-hand navigation.
26 Submit Documentation Feedback Copyright © 1999–2014, Texas Instruments Incorporated
Product Folder Links: LM7171
PACKAGE OPTION ADDENDUM
www.ti.com 19-Mar-2015
Addendum-Page 1
PACKAGING INFORMATION
Orderable Device Status
(1)
Package Type Package
Drawing Pins Package
Qty Eco Plan
(2)
Lead/Ball Finish
(6)
MSL Peak Temp
(3)
Op Temp (°C) Device Marking
(4/5)
Samples
LM7171AIM NRND SOIC D 8 95 TBD Call TI Call TI -40 to 85 LM71
71AIM
LM7171AIM/NOPB ACTIVE SOIC D 8 95 Green (RoHS
& no Sb/Br) CU SN Level-1-260C-UNLIM -40 to 85 LM71
71AIM
LM7171AIMX/NOPB ACTIVE SOIC D 8 2500 Green (RoHS
& no Sb/Br) CU SN Level-1-260C-UNLIM -40 to 85 LM71
71AIM
LM7171BIM NRND SOIC D 8 95 TBD Call TI Call TI -40 to 85 LM71
71BIM
LM7171BIM/NOPB ACTIVE SOIC D 8 95 Green (RoHS
& no Sb/Br) CU SN Level-1-260C-UNLIM -40 to 85 LM71
71BIM
LM7171BIMX/NOPB ACTIVE SOIC D 8 2500 Green (RoHS
& no Sb/Br) CU SN Level-1-260C-UNLIM -40 to 85 LM71
71BIM
LM7171BIN/NOPB ACTIVE PDIP P 8 40 Green (RoHS
& no Sb/Br) CU SN Level-1-NA-UNLIM -40 to 85 LM7171
BIN
(1) The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
(2) Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check http://www.ti.com/productcontent for the latest availability
information and additional product content details.
TBD: The Pb-Free/Green conversion plan has not been defined.
Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements for all 6 substances, including the requirement that
lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes.
Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and package, or 2) lead-based die adhesive used between
the die and leadframe. The component is otherwise considered Pb-Free (RoHS compatible) as defined above.
Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame retardants (Br or Sb do not exceed 0.1% by weight
in homogeneous material)
(3) MSL, Peak Temp. - The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature.
(4) There may be additional marking, which relates to the logo, the lot trace code information, or the environmental category on the device.
PACKAGE OPTION ADDENDUM
www.ti.com 19-Mar-2015
Addendum-Page 2
(5) Multiple Device Markings will be inside parentheses. Only one Device Marking contained in parentheses and separated by a "~" will appear on a device. If a line is indented then it is a continuation
of the previous line and the two combined represent the entire Device Marking for that device.
(6) Lead/Ball Finish - Orderable Devices may have multiple material finish options. Finish options are separated by a vertical ruled line. Lead/Ball Finish values may wrap to two lines if the finish
value exceeds the maximum column width.
Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information
provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and
continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals.
TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release.
In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis.
TAPE AND REEL INFORMATION
*All dimensions are nominal
Device Package
Type Package
Drawing Pins SPQ Reel
Diameter
(mm)
Reel
Width
W1 (mm)
A0
(mm) B0
(mm) K0
(mm) P1
(mm) W
(mm) Pin1
Quadrant
LM7171AIMX/NOPB SOIC D 8 2500 330.0 12.4 6.5 5.4 2.0 8.0 12.0 Q1
LM7171BIMX/NOPB SOIC D 8 2500 330.0 12.4 6.5 5.4 2.0 8.0 12.0 Q1
PACKAGE MATERIALS INFORMATION
www.ti.com 5-Dec-2014
Pack Materials-Page 1
*All dimensions are nominal
Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm)
LM7171AIMX/NOPB SOIC D 8 2500 367.0 367.0 35.0
LM7171BIMX/NOPB SOIC D 8 2500 367.0 367.0 35.0
PACKAGE MATERIALS INFORMATION
www.ti.com 5-Dec-2014
Pack Materials-Page 2
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