LM6171
www.ti.com
SNOS745C – MAY 1998 – REVISED MARCH 2013
LM6171 High Speed Low Power Low Distortion Voltage Feedback Amplifier
Check for Samples: LM6171
FEATURES
DESCRIPTION
•
•
•
•
•
•
•
•
•
The LM6171 is a high speed unity-gain stable voltage
feedback amplifier. It offers a high slew rate of
3600V/μs and a unity-gain bandwidth of 100 MHz
while consuming only 2.5 mA of supply current. The
LM6171 has very impressive AC and DC
performance which is a great benefit for high speed
signal processing and video applications.
1
23
(Typical Unless Otherwise Noted)
Easy-To-Use Voltage Feedback Topology
Very High Slew Rate: 3600V/μs
Wide Unity-Gain-Bandwidth Product: 100 MHz
−3dB Frequency @ AV = +2: 62 MHz
Low Supply Current: 2.5 mA
High CMRR: 110 dB
High Open Loop Gain: 90 dB
Specified for ±15V and ±5V Operation
APPLICATIONS
•
•
•
•
•
•
•
•
•
Multimedia Broadcast Systems
Line Drivers, Switchers
Video Amplifiers
NTSC, PAL® and SECAM Systems
ADC/DAC Buffers
HDTV Amplifiers
Pulse Amplifiers and Peak Detectors
Instrumentation Amplifier
Active Filters
The ±15V power supplies allow for large signal
swings and give greater dynamic range and signal-tonoise ratio. The LM6171 has high output current
drive, low SFDR and THD, ideal for ADC/DAC
systems. The LM6171 is specified for ±5V operation
for portable applications.
The LM6171 is built on TI's advanced VIP III
(Vertically Integrated PNP) complementary bipolar
process.
CONNECTION DIAGRAM
Figure 1. Top View
8-Pin SOIC/PDIP
See Package Number D (SOIC) or
See Package Number P (PDIP)
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.
1
2
3
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
PAL is a registered trademark of and used under lisence from Advanced Micro Devices, Inc..
All other trademarks are the property of their respective owners.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 1998–2013, Texas Instruments Incorporated
LM6171
SNOS745C – MAY 1998 – REVISED MARCH 2013
www.ti.com
Absolute Maximum Ratings (1) (2)
ESD Tolerance (3)
2.5 kV
Supply Voltage (V+–V−)
36V
Differential Input Voltage
±10V
V++0.3V to V− −0.3V
Common-Mode Voltage Range
Input Current
±10mA
Output Short Circuit to Ground (4)
Continuous
−65°C to +150°C
Storage Temperature Range
Maximum Junction Temperature
(5)
Soldering Information
(1)
(2)
(3)
(4)
(5)
150°C
Infrared or Convection Reflow
(20 sec.)
235°C
Wave Soldering Lead Temp
(10 sec.)
260°C
If Military/Aerospace specified devices are required, please contact the Texas Instruments Sales Office/Distributors for availability and
specifications.
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 guaranteed. For guaranteed specifications and the test
conditions, see the Electrical Characteristics.
Human body model, 1.5 kΩ in series with 100 pF.
Continuous short circuit operation at elevated ambient temperature can result in exceeding the maximum allowed junction temperature
of 150°C.
The maximum power dissipation is a function of TJ(max), θJA, and TA. The maximum allowable power dissipation at any ambient
temperature is PD = (TJ(max) − TA)/θJA. All numbers apply for packages soldered directly into a PC board.
Operating Ratings (1)
5.5V ≤ VS ≤ 34V
Supply Voltage
−40°C to +85°C
Operating Temperature Range
LM6171AI, LM6171BI
Thermal Resistance (θJA)
P Package, 8-Pin PDIP
108°C/W
D Package, 8-Pin SOIC
172°C/W
(1)
2
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 guaranteed. For guaranteed specifications and the test
conditions, see the Electrical Characteristics.
Submit Documentation Feedback
Copyright © 1998–2013, Texas Instruments Incorporated
Product Folder Links: LM6171
LM6171
www.ti.com
SNOS745C – MAY 1998 – REVISED MARCH 2013
±15V DC Electrical Characteristics
Unless otherwise specified, all limits guaranteed for TJ = 25°C, V+ = +15V, V− = −15V, VCM = 0V, and RL = 1 kΩ. Boldface
limits apply at the temperature extremes
Symbol
Parameter
Conditions
Typ
(1)
LM6171AI
Limit
LM6171BI
Limit
3
6
mV
5
8
max
(2)
VOS
Input Offset Voltage
1.5
TC VOS
Input Offset Voltage Average Drift
6
IB
Input Bias Current
1
IOS
Input Offset Current
RIN
Input Resistance
RO
Open Loop Output Resistance
CMRR
Common Mode Rejection Ratio
0.03
Common Mode
40
Differential Mode
4.9
VCM = ±10V
110
max
2
2
μA
3
3
max
MΩ
Ω
dB
min
85
80
dB
80
75
min
80
80
dB
70
70
min
70
70
dB
60
60
min
13.3
12.5
12.5
V
12
12
min
−13.3
−12.5
−12.5
V
−12
−12
max
CMRR ≥ 60 dB
AV
Large Signal Voltage Gain (3)
RL = 1 kΩ
90
RL = 100Ω
83
RL = 1 kΩ
RL = 100Ω
95
±13.5
11.6
−10.5
Continuous Output Current (Open Loop) (4) Sourcing, RL = 100Ω
(4)
μA
4
70
Input Common-Mode Voltage Range
(1)
(2)
(3)
3
4
75
VCM
IS
3
75
VS = ±15V to ±5V
ISC
μV/°C
80
Power Supply Rejection Ratio
Output Swing
(2)
14
PSRR
VO
Units
116
V
9
9
V
8.5
8.5
min
−9
−9
V
−8.5
−8.5
max
90
90
mA
85
85
min
90
90
mA
85
85
max
Sinking, RL = 100Ω
105
Continuous Output Current (in Linear
Region)
Sourcing, RL = 10Ω
100
mA
Sinking, RL = 10Ω
80
mA
Output Short Circuit Current
Sourcing
135
mA
Sinking
135
Supply Current
2.5
mA
4
4
mA
4.5
4.5
max
Typical Values represent the most likely parametric norm.
All limits are guaranteed by testing or statistical analysis.
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.
The open loop output current is the output swing with the 100Ω load resistor divided by that resistor.
Submit Documentation Feedback
Copyright © 1998–2013, Texas Instruments Incorporated
Product Folder Links: LM6171
3
LM6171
SNOS745C – MAY 1998 – REVISED MARCH 2013
www.ti.com
±15V AC Electrical Characteristics
Unless otherwise specified, all limits guaranteed for TJ = 25°C, V+ = +15V, V− = −15V, VCM = 0V, and RL = 1 kΩ. Boldface
limits apply at the temperature extremes
Symbol
Parameter
Conditions
Typ
(1)
LM6171AI
Limit
(2)
SR
Slew Rate
GBW
(3)
AV = +2, VIN = 13 VPP
3600
AV = +2, VIN = 10 VPP
3000
Unity Gain-Bandwidth Product
−3 dB Frequency
LM6171BI
Limit
Units
(2)
V/μs
100
MHz
AV = +1
160
MHz
AV = +2
62
MHz
40
deg
φm
Phase Margin
ts
Settling Time (0.1%)
AV = −1, VOUT = ±5V RL =
500Ω
48
ns
Propagation Delay
VIN = ±5V, RL = 500Ω, AV =
−2
6
ns
AD
Differential Gain (4)
0.03
%
φD
Differential Phase (4)
0.5
deg
en
Input-Referred Voltage Noise
f = 1 kHz
12
nV/√Hz
in
Input-Referred Current Noise
f = 1 kHz
1
pA/√Hz
(1)
(2)
(3)
(4)
4
Typical Values represent the most likely parametric norm.
All limits are guaranteed by testing or statistical analysis.
Slew rate is the average of the rising and falling slew rates.
Differential gain and phase are measured with AV = +2, VIN = 1 VPP at 3.58 MHz and both input and output 75Ω terminated.
Submit Documentation Feedback
Copyright © 1998–2013, Texas Instruments Incorporated
Product Folder Links: LM6171
LM6171
www.ti.com
SNOS745C – MAY 1998 – REVISED MARCH 2013
±5V DC Electrical Characteristics
Unless otherwise specified, all limits guaranteed for TJ = 25°C, V+ = +5V, V− = −5V, VCM = 0V, and RL = 1 kΩ. Boldface limits
apply at the temperature extremes
Symbol
Parameter
Conditions
Typ
(1)
LM6171AI
Limit
LM6171BI
Limit
3
6
mV
5
8
max
(2)
VOS
Input Offset Voltage
1.2
TC VOS
Input Offset Voltage Average Drift
4
IB
Input Bias Current
1
IOS
Input Offset Current
RIN
Input Resistance
RO
Open Loop Output Resistance
CMRR
Common Mode Rejection Ratio
0.03
Common Mode
40
Differential Mode
4.9
VCM = ±2.5V
Power Supply Rejection Ratio
VS = ±15V to ±5V
VCM
Input Common-Mode Voltage
Range
CMRR ≥ 60 dB
AV
Large Signal Voltage Gain (3)
RL = 1 kΩ
RL = 100Ω
Output Swing
RL = 1 kΩ
RL = 100Ω
105
95
Sourcing, RL = 100Ω
Sinking, RL = 100Ω
ISC
Output Short Circuit Current
IS
Supply Current
(1)
(2)
(3)
(4)
μV/°C
2.5
2.5
μA
3.5
3.5
max
1.5
1.5
μA
2.2
2.2
max
MΩ
Ω
80
75
dB
75
70
min
85
80
dB
80
75
min
±3.7
84
V
75
75
dB
65
65
min
70
70
dB
60
60
min
3.2
3.2
V
3
3
min
−3.4
−3.2
−3.2
V
−3
−3
max
3.2
2.8
2.8
V
2.5
2.5
min
−2.8
−2.8
V
−2.5
−2.5
max
28
28
mA
25
25
min
28
28
mA
25
25
max
80
3.5
−3.0
Continuous Output Current (Open
Loop) (4)
(2)
14
PSRR
VO
Units
32
30
Sourcing
130
Sinking
100
2.3
mA
mA
3
3
mA
3.5
3.5
max
Typical Values represent the most likely parametric norm.
All limits are guaranteed by testing or statistical analysis.
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.
The open loop output current is the output swing with the 100Ω load resistor divided by that resistor.
Submit Documentation Feedback
Copyright © 1998–2013, Texas Instruments Incorporated
Product Folder Links: LM6171
5
LM6171
SNOS745C – MAY 1998 – REVISED MARCH 2013
www.ti.com
±5V AC Electrical Characteristics
Unless otherwise specified, all limits guaranteed for TJ = 25°C, V+ = +5V, V− = −5V, VCM = 0V, and RL = 1 kΩ. Boldface limits
apply at the temperature extremes
Symbol
Parameter
Conditions
Typ
(1)
LM6171AI
Limit
(2)
(3)
SR
Slew Rate
GBW
Unity Gain-Bandwidth Product
AV = +2, VIN = 3.5 VPP
−3 dB Frequency
LM6171BI
Limit
Units
(2)
750
V/μs
70
MHz
AV = +1
130
MHz
AV = +2
45
φm
Phase Margin
57
deg
ts
Settling Time (0.1%)
AV = −1, VOUT = +1V, RL =
500Ω
60
ns
Propagation Delay
VIN = ±1V, RL = 500Ω, AV =
−2
8
ns
0.04
%
AD
Differential Gain (4)
(4)
φD
Differential Phase
0.7
deg
en
Input-Referred Voltage Noise
f = 1 kHz
11
nV/√Hz
in
Input-Referred Current Noise
f = 1 kHz
1
pA/√Hz
(1)
(2)
(3)
(4)
6
Typical Values represent the most likely parametric norm.
All limits are guaranteed by testing or statistical analysis.
Slew rate is the average of the rising and falling slew rates.
Differential gain and phase are measured with AV = +2, VIN = 1 VPP at 3.58 MHz and both input and output 75Ω terminated.
Submit Documentation Feedback
Copyright © 1998–2013, Texas Instruments Incorporated
Product Folder Links: LM6171
LM6171
www.ti.com
SNOS745C – MAY 1998 – REVISED MARCH 2013
Typical Performance Characteristics
Unless otherwise noted, TA = 25°C
Supply Current
vs.
Supply Voltage
Supply Current
vs.
Temperature
Figure 2.
Figure 3.
Input Offset Voltage
vs.
Temperature
Input Bias Current
vs.
Temperature
Figure 4.
Figure 5.
Input Offset Voltage
vs.
Common Mode Voltage
Short Circuit Current
vs.
Temperature (Sourcing)
Figure 6.
Figure 7.
Submit Documentation Feedback
Copyright © 1998–2013, Texas Instruments Incorporated
Product Folder Links: LM6171
7
LM6171
SNOS745C – MAY 1998 – REVISED MARCH 2013
www.ti.com
Typical Performance Characteristics (continued)
Unless otherwise noted, TA = 25°C
8
Short Circuit Current
vs.
Temperature (Sinking)
Output Voltage
vs.
Output Current
Figure 8.
Figure 9.
Output Voltage
vs.
Output Current
CMRR
vs.
Frequency
Figure 10.
Figure 11.
PSRR
vs.
Frequency
PSRR
vs.
Frequency
Figure 12.
Figure 13.
Submit Documentation Feedback
Copyright © 1998–2013, Texas Instruments Incorporated
Product Folder Links: LM6171
LM6171
www.ti.com
SNOS745C – MAY 1998 – REVISED MARCH 2013
Typical Performance Characteristics (continued)
Unless otherwise noted, TA = 25°C
Open Loop Frequency Response
Open Loop Frequency Response
Figure 14.
Figure 15.
Gain Bandwidth Product
vs.
Supply Voltage
Gain Bandwidth Product
vs.
Load Capacitance
Figure 16.
Figure 17.
Large Signal Voltage Gain
vs.
Load
Large Signal Voltage Gain
vs.
Load
Figure 18.
Figure 19.
Submit Documentation Feedback
Copyright © 1998–2013, Texas Instruments Incorporated
Product Folder Links: LM6171
9
LM6171
SNOS745C – MAY 1998 – REVISED MARCH 2013
www.ti.com
Typical Performance Characteristics (continued)
Unless otherwise noted, TA = 25°C
10
Input Voltage Noise
vs.
Frequency
Input Voltage Noise
vs.
Frequency
Figure 20.
Figure 21.
Input Current Noise
vs.
Frequency
Input Current Noise
vs.
Frequency
Figure 22.
Figure 23.
Slew Rate
vs.
Supply Voltage
Slew Rate
vs.
Input Voltage
Figure 24.
Figure 25.
Submit Documentation Feedback
Copyright © 1998–2013, Texas Instruments Incorporated
Product Folder Links: LM6171
LM6171
www.ti.com
SNOS745C – MAY 1998 – REVISED MARCH 2013
Typical Performance Characteristics (continued)
Unless otherwise noted, TA = 25°C
Slew Rate
vs.
Load Capacitance
Open Loop Output Impedance
vs.
Frequency
Figure 26.
Figure 27.
Open Loop Output Impedance
vs.
Frequency
Large Signal Pulse Response
AV = −1, VS = ±15V
Figure 28.
Figure 29.
Large Signal Pulse Response
AV = −1, VS = ±5V
Large Signal Pulse Response
AV = +1, VS = ±15V
Figure 30.
Figure 31.
Submit Documentation Feedback
Copyright © 1998–2013, Texas Instruments Incorporated
Product Folder Links: LM6171
11
LM6171
SNOS745C – MAY 1998 – REVISED MARCH 2013
www.ti.com
Typical Performance Characteristics (continued)
Unless otherwise noted, TA = 25°C
12
Large Signal Pulse Response
AV = +1, VS = ±5V
Large Signal Pulse Response
AV = +2, VS = ±15V
Figure 32.
Figure 33.
Large Signal Pulse Response
AV = +2, VS = ±5V
Small Signal Pulse Response
AV = −1, VS = ±15V
Figure 34.
Figure 35.
Small Signal Pulse Response
AV = −1, VS = ±5V
Small Signal Pulse Response
AV = +1, VS = ±15V
Figure 36.
Figure 37.
Submit Documentation Feedback
Copyright © 1998–2013, Texas Instruments Incorporated
Product Folder Links: LM6171
LM6171
www.ti.com
SNOS745C – MAY 1998 – REVISED MARCH 2013
Typical Performance Characteristics (continued)
Unless otherwise noted, TA = 25°C
Small Signal Pulse Response
AV = +1, VS = ±5V
Small Signal Pulse Response
AV = +2, VS = ±15V
Figure 38.
Figure 39.
Small Signal Pulse Response
AV = +2, VS = ±5V
Closed Loop Frequency Response
vs.
SupplyVoltage
(AV = +1)
Figure 40.
Figure 41.
Closed Loop Frequency Response
vs.
Supply Voltage
(AV = +2)
Closed Loop Frequency Response
vs.
Capacitive Load
(AV = +1)
Figure 42.
Figure 43.
Submit Documentation Feedback
Copyright © 1998–2013, Texas Instruments Incorporated
Product Folder Links: LM6171
13
LM6171
SNOS745C – MAY 1998 – REVISED MARCH 2013
www.ti.com
Typical Performance Characteristics (continued)
Unless otherwise noted, TA = 25°C
14
Closed Loop Frequency Response
vs.
Capacitive Load
(AV = +1)
Closed Loop Frequency Response
vs.
Capacitive Load
(AV = +2)
Figure 44.
Figure 45.
Closed Loop Frequency Response
vs.
Capacitive Load
(AV = +2)
Total Harmonic Distortion
vs.
Frequency
Figure 46.
Figure 47.
Total Harmonic Distortion
vs.
Frequency
Total Harmonic Distortion
vs.
Frequency
Figure 48.
Figure 49.
Submit Documentation Feedback
Copyright © 1998–2013, Texas Instruments Incorporated
Product Folder Links: LM6171
LM6171
www.ti.com
SNOS745C – MAY 1998 – REVISED MARCH 2013
Typical Performance Characteristics (continued)
Unless otherwise noted, TA = 25°C
Total Harmonic Distortion
vs.
Frequency
Undistorted Output Swing
vs.
Frequency
Figure 50.
Figure 51.
Undistorted Output Swing
vs.
Frequency
Undistorted Output Swing
vs.
Frequency
Figure 52.
Figure 53.
Undistorted Output Swing
vs.
Frequency
Total Power Dissipation
vs.
Ambient Temperature
Figure 54.
Figure 55.
Submit Documentation Feedback
Copyright © 1998–2013, Texas Instruments Incorporated
Product Folder Links: LM6171
15
LM6171
SNOS745C – MAY 1998 – REVISED MARCH 2013
www.ti.com
LM6171 SIMPLIFIED SCHEMATIC
Figure 56.
16
Submit Documentation Feedback
Copyright © 1998–2013, Texas Instruments Incorporated
Product Folder Links: LM6171
LM6171
www.ti.com
SNOS745C – MAY 1998 – REVISED MARCH 2013
APPLICATION INFORMATION
LM6171 PERFORMANCE DISCUSSION
The LM6171 is a high speed, unity-gain stable voltage feedback amplifier. It consumes only 2.5 mA supply
current while providing a gain-bandwidth product of 100 MHz and a slew rate of 3600V/μs. It also has other great
features such as low differential gain and phase and high output current. The LM6171 is a good choice in high
speed circuits.
The LM6171 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 will couple with feedback capacitor and
cause oscillation. As a result, CFAs cannot be used in traditional op amp circuits such as photodiode amplifiers,
I-to-V converters and integrators.
LM6171 CIRCUIT OPERATION
The class AB input stage in LM6171 is fully symmetrical and has a similar slewing characteristic to the current
feedback amplifiers. In LM6171 Figure 56, Q1 through Q4 form the equivalent of the current feedback input
buffer, RE the 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.
LM6171 SLEW RATE CHARACTERISTIC
The slew rate of LM6171 is determined by the current available to charge and discharge an internal high
impedance node capacitor. The 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.
When a very fast large signal pulse is applied to the input of an amplifier, some overshoot or undershoot occurs.
By placing an external series resistor such as 1 kΩ to the input of LM6171, the bandwidth is reduced to help
lower the overshoot.
LAYOUT CONSIDERATION
Printed Circuit Boards 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 and frustrating 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 frequency performance. It is better to solder the amplifier directly into the PC board
without using any socket.
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.
Components Selection And Feedback Resistor
It is important in high speed applications to keep all component leads short because wires are inductive at high
frequency. 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 LM6171, a feedback resistor of 510Ω gives optimal
performance.
Submit Documentation Feedback
Copyright © 1998–2013, Texas Instruments Incorporated
Product Folder Links: LM6171
17
LM6171
SNOS745C – MAY 1998 – REVISED MARCH 2013
www.ti.com
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 LM6171, a feedback capacitor of 2 pF is recommended. Figure 57 illustrates
the compensation circuit.
Figure 57. Compensating for Input Capacitance
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 58. Power Supply Bypassing
TERMINATION
In high frequency applications, reflections occur if signals are not properly terminated. Figure 59 shows a
properly terminated signal while Figure 60 shows an improperly terminated signal.
18
Submit Documentation Feedback
Copyright © 1998–2013, Texas Instruments Incorporated
Product Folder Links: LM6171
LM6171
www.ti.com
SNOS745C – MAY 1998 – REVISED MARCH 2013
Figure 59. Properly Terminated Signal
Figure 60. 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 75Ω characteristic impedance, and RG58 has 50Ω characteristic impedance.
Submit Documentation Feedback
Copyright © 1998–2013, Texas Instruments Incorporated
Product Folder Links: LM6171
19
LM6171
SNOS745C – MAY 1998 – REVISED MARCH 2013
www.ti.com
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 below in Figure 61. The combination of the isolation resistor
and the load capacitor forms a pole to increase stablility 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 LM6171, a 50Ω isolation resistor is recommended for initial
evaluation. Figure 62 shows the LM6171 driving a 200 pF load with the 50Ω isolation resistor.
Figure 61. Isolation Resistor Used to Drive Capacitive Load
Figure 62. The LM6171 Driving a 200 pF Load with a 50Ω Isolation Resistor
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
TA is the ambient temperature
θJA is the thermal resistance of a particular package
(2)
For example, for the LM6171 in a SOIC-8 package, the maximum power dissipation at 25°C ambient
temperature is 730 mW.
20
Submit Documentation Feedback
Copyright © 1998–2013, Texas Instruments Incorporated
Product Folder Links: LM6171
LM6171
www.ti.com
SNOS745C – MAY 1998 – REVISED MARCH 2013
Thermal resistance, θJA, depends on parameters such as die size, package size and package material. The
smaller the die size and package, the higher θJA becomes. The 8-pin PDIP package has a lower thermal
resistance (108°C/W) than that of 8-pin SOIC-8 (172°C/W). Therefore, for higher dissipation capability, use an 8pin PDIP package.
The total power dissipated in a device can be calculated as:
PD = PQ + PL
(3)
PQ is the quiescent power dissipated in a device with no load connected at the output. PL is the power dissipated
in the device with a load connected at the output; it is not the power dissipated by the load.
Furthermore,
PQ = supply current × total supply voltage with no load
PL = output current × (voltage difference between supply voltage and output voltage of the same supply)
For example, the total power dissipated by the LM6171 with VS = ±15V and output voltage of 10V into 1 kΩ load
resistor (one end tied to ground) is
PD = PQ + PL
= (2.5 mA) × (30V) + (10 mA) × (15V − 10V)
= 75 mW + 50 mW
= 125 mW
APPLICATION CIRCUITS
Figure 63. Fast Instrumentation Amplifier
Submit Documentation Feedback
Copyright © 1998–2013, Texas Instruments Incorporated
Product Folder Links: LM6171
21
LM6171
SNOS745C – MAY 1998 – REVISED MARCH 2013
Figure 64. Multivibrator
22
www.ti.com
Figure 65. Pulse Width Modulator
Submit Documentation Feedback
Copyright © 1998–2013, Texas Instruments Incorporated
Product Folder Links: LM6171
LM6171
www.ti.com
SNOS745C – MAY 1998 – REVISED MARCH 2013
REVISION HISTORY
Changes from Revision B (March 2013) to Revision C
•
Page
Changed layout of National Data Sheet to TI format .......................................................................................................... 21
Submit Documentation Feedback
Copyright © 1998–2013, Texas Instruments Incorporated
Product Folder Links: LM6171
23
PACKAGE OPTION ADDENDUM
www.ti.com
27-May-2022
PACKAGING INFORMATION
Orderable Device
Status
(1)
Package Type Package Pins Package
Drawing
Qty
Eco Plan
(2)
Lead finish/
Ball material
MSL Peak Temp
Op Temp (°C)
Device Marking
(3)
Samples
(4/5)
(6)
LM6171AIM
NRND
SOIC
D
8
95
Non-RoHS
& Green
Call TI
Level-1-235C-UNLIM
-40 to 85
LM61
71AIM
LM6171AIM/NOPB
ACTIVE
SOIC
D
8
95
RoHS & Green
SN
Level-1-260C-UNLIM
-40 to 85
LM61
71AIM
Samples
LM6171AIMX/NOPB
ACTIVE
SOIC
D
8
2500
RoHS & Green
SN
Level-1-260C-UNLIM
-40 to 85
LM61
71AIM
Samples
LM6171BIM
NRND
SOIC
D
8
95
Non-RoHS
& Green
Call TI
Level-1-235C-UNLIM
-40 to 85
LM61
71BIM
LM6171BIM/NOPB
ACTIVE
SOIC
D
8
95
RoHS & Green
SN
Level-1-260C-UNLIM
-40 to 85
LM61
71BIM
Samples
LM6171BIMX/NOPB
ACTIVE
SOIC
D
8
2500
RoHS & Green
SN
Level-1-260C-UNLIM
-40 to 85
LM61
71BIM
Samples
LM6171BIN/NOPB
ACTIVE
PDIP
P
8
40
RoHS & Green
NIPDAU
Level-1-NA-UNLIM
-40 to 85
LM6171
BIN
Samples
(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)
RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance
do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may
reference these types of products as "Pb-Free".
RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption.
Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of
工商网监
湘ICP备2023018690号
