NSC LM6144AIN

LM6142 Dual and LM6144 Quad
High Speed/Low Power 17 MHz Rail-to-Rail Input-Output
Operational Amplifiers
General Description
Features
Using patent pending new circuit topologies, the LM6142/44
provides new levels of performance in applications where
low voltage supplies or power limitations previously made
compromise necessary. Operating on supplies of 1.8V to
over 24V, the LM6142/44 is an excellent choice for battery
operated systems, portable instrumentation and others.
The greater than rail-to-rail input voltage range eliminates
concern over exceeding the common-mode voltage range.
The rail-to-rail output swing provides the maximum possible
dynamic range at the output. This is particularly important
when operating on low supply voltages.
High gain-bandwidth with 650 µA/Amplifier supply current
opens new battery powered applications where previous
higher power consumption reduced battery life to unacceptable levels. The ability to drive large capacitive loads without
oscillating functionally removes this common problem.
At VS = 5V. Typ unless noted.
n Rail-to-rail input CMVR −0.25V to 5.25V
n Rail-to-rail output swing 0.005V to 4.995V
n Wide gain-bandwidth: 17 MHz at 50 kHz (typ)
n Slew rate:
Small signal, 5V/µs
Large signal, 30V/µs
n Low supply current 650 µA/Amplifier
n Wide supply range 1.8V to 24V
n CMRR 107 dB
n Gain 108 dB with RL = 10k
n PSRR 87 dB
Applications
n
n
n
n
n
Battery operated instrumentation
Depth sounders/fish finders
Barcode scanners
Wireless communications
Rail-to-rail in-out instrumentation amps
Connection Diagrams
8-Pin CDIP
8-Pin DIP/SO
DS012057-14
Top View
© 1999 National Semiconductor Corporation
DS012057-1
Top View
DS012057
www.national.com
LM6142 Dual and LM6144 Quad High Speed/Low Power 17 MHz Rail-to-Rail Input-Output
Operational Amplifiers
May 1999
Connection Diagrams
(Continued)
14-Pin DIP/SO
DS012057-2
Top View
Ordering Information
Package
Temperature Range
Temperature Range
Industrial
Military
−40˚C to +85˚C
−55˚C to +125˚C
NSC
Drawing
8-Pin Molded DIP
LM6142AIN, LM6142BIN
N08E
8-Pin Small Outline
LM6142AIM, LM6142BIM
M08A
14-Pin Molded DIP
LM6144AIN, LM6144BIN
N14A
14-Pin Small Outline
LM6144AIM, LM6144BIM
M14A
8-Pin CDIP
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LM6142AMJ-QML
2
J08A
Absolute Maximum Ratings (Note 1)
Storage Temp. Range
Junction Temperature (Note 4)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
ESD Tolerance (Note 2)
Differential Input Voltage
Voltage at Input/Output Pin
Supply Voltage (V+ − V−)
Current at Input Pin
Current at Output Pin (Note 3)
Current at Power Supply Pin
Lead Temperature
(soldering, 10 sec)
−65˚C to +150˚C
150˚C
Operating Ratings (Note 1)
2500V
15V
(V+) + 0.3V, (V−) − 0.3V
35V
± 10 mA
± 25 mA
50 mA
Supply Voltage
Junction Temperature Range
LM6142, LM6144
Thermal Resistance (θJA)
N Package, 8-Pin Molded DIP
M Package, 8-Pin Surface Mount
N Package, 14-Pin Molded DIP
M Package, 14-Pin Surface Mount
1.8V ≤ V+ ≤ 24V
−40˚C ≤ TJ ≤ +85˚C
115˚C/W
193˚C/W
81˚C/W
126˚C/W
260˚C
5.0V DC Electrical Characteristics
Unless otherwise specified, all limits guaranteed for TJ = 25˚C, V+ = 5.0V, V− = 0V, VCM = VO = V+/2 and RL > 1 MΩ to
V+/2. Boldface limits apply at the temperature extremes.
Symbol
VOS
TCVOS
Parameter
Conditions
Input Offset Voltage
LM6144AI
LM6144BI
Typ
LM6142AI
LM6142BI
(Note 5)
Limit
Limit
(Note 6)
(Note 6)
1.0
2.5
mV
2.2
3.3
max
0.3
Input Offset Voltage
3
Units
µV/˚C
Average Drift
IB
Input Bias Current
0V ≤ VCM ≤ 5V
170
250
180
280
526
IOS
Input Offset Current
RIN
Input Resistance, CM
CMRR
Common Mode
3
Power Supply
AV
nA
80
max
84
MΩ
84
78
78
0V ≤ VCM ≤ 5V
82
66
66
79
64
64
87
80
80
78
78
dB
min
Input Common-Mode
−0.25
0
0
Voltage Range
5.25
5.0
5.0
270
100
80
V/mV
70
33
25
min
0.005
0.01
0.01
V
0.013
0.013
max
Large Signal
RL = 10k
Voltage Gain
VO
30
80
107
Rejection Ratio
VCM
526
126
5V ≤ V+ ≤ 24V
nA
max
30
0V ≤ VCM ≤ 4V
Rejection Ratio
PSRR
300
Output Swing
RL = 100k
4.995
RL = 10k
4.98
4.98
V
4.93
4.93
min
0.02
V max
4.97
RL = 2k
0.06
4.90
3
V
V min
0.1
0.1
V
0.133
0.133
max
4.86
4.86
V
4.80
4.80
min
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5.0V DC Electrical Characteristics
(Continued)
Unless otherwise specified, all limits guaranteed for TJ = 25˚C, V+ = 5.0V, V− = 0V, VCM = VO = V+/2 and RL > 1 MΩ to
V+/2. Boldface limits apply at the temperature extremes.
LM6144AI
LM6144BI
Typ
LM6142AI
LM6142BI
(Note 5)
Limit
Limit
(Note 6)
(Note 6)
10
8
mA
Circuit Current
4.9
4
min
LM6142
35
35
Symbol
Parameter
Output Short
ISC
Conditions
Sourcing
13
Units
mA
max
Sinking
24
10
10
mA
5.3
5.3
min
35
35
mA
max
ISC
Output Short
6
6
mA
Circuit Current
Sourcing
8
3
3
min
LM6144
35
35
mA
max
Sinking
22
8
8
mA
4
4
min
35
35
mA
max
IS
Supply Current
Per Amplifier
650
800
800
µA
880
880
max
5.0V AC Electrical Characteristics
Unless Otherwise Specified, All Limits Guaranteed for TJ = 25˚C, V+ = 5.0V, V− = 0V, VCM = VO = V+/2 and RL > 1 MΩ to
VS/2. Boldface limits apply at the temperature extremes.
Symbol
Parameter
Conditions
Slew Rate
8 Vp-p @ VCC 12V
GBW
Gain-Bandwidth Product
RS > 1 kΩ
f = 50 kHz
φm
Phase Margin
SR
Input-Referred
LM6144BI
LM6142AI
LM6142BI
(Note 5)
Limit
Limit
(Note 6)
(Note 6)
25
17
Amp-to-Amp Isolation
en
LM6144AI
Typ
Units
15
13
13
11
V/µs
min
10
10
MHz
6
6
min
38
Deg
130
dB
f = 1 kHz
16
f = 1 kHz
0.22
f = 10 kHz, RL = 10 kΩ,
0.003
Voltage Noise
in
Input-Referred
Current Noise
T.H.D.
Total Harmonic Distortion
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4
%
2.7V DC Electrical Characteristics
Unless Otherwise Specified, All Limits Guaranteed for TJ = 25˚C, V+ = 2.7V, V− = 0V, VCM = VO = V+/2 and RL > 1 MΩ to
V+/2. Boldface limits apply at the temperature extreme
Symbol
VOS
IB
IOS
Parameter
Conditions
Input Offset Voltage
LM6144AI
LM6144BI
Typ
LM6142AI
LM6142BI
(Note 5)
Limit
Limit
(Note 6)
(Note 6)
1.8
2.5
mV
4.3
4.3
max
250
300
nA
526
526
max
30
30
nA
80
80
max
0.4
Input Bias Current
150
Input Offset Current
4
Units
RIN
Input Resistance
128
MΩ
CMRR
Common Mode
0V ≤ VCM ≤ 1.8V
90
Rejection Ratio
0V ≤ VCM ≤ 2.7V
76
dB
min
Power Supply
3V ≤ V+ ≤ 5V
79
PSRR
Rejection Ratio
VCM
AV
Input Common-Mode
−0.25
0
0
V min
Voltage Range
2.95
2.7
2.7
V max
Large Signal
RL = 10k
55
V/mV
Voltage Gain
VO
Output Swing
min
RL = 10 kΩ
0.019
2.67
IS
Supply Current
Per Amplifier
510
0.08
0.08
V
0.112
0.112
max
2.66
2.66
V
2.25
2.25
min
800
800
µA
880
880
max
2.7V AC Electrical Characteristics
Unless Otherwise Specified, All Limits Guaranteed for TJ = 25˚C, V+ = 2.7V, V− = 0V, VCM = VO = V+/2 and RL > 1 MΩ to
V+/2. Boldface limits apply at the temperature extreme
Symbol
Parameter
GBW
Gain-Bandwidth Product
φm
Gm
Conditions
f = 50 kHz
LM6144AI
LM6144BI
Typ
LM6142AI
LM6142BI
(Note 5)
Limit
Limit
(Note 6)
(Note 6)
Units
9
MHz
Phase Margin
36
Deg
Gain Margin
6
dB
5
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24V Electrical Characteristics
Unless Otherwise Specified, All Limits Guaranteed for TJ = 25˚C, V+ = 24V, V− = 0V, VCM = VO = V+/2 and RL > 1 MΩ to
VS/2. Boldface limits apply at the temperature extreme
Symbol
VOS
IB
Parameter
Conditions
Input Offset Voltage
LM6144AI
LM6144BI
Typ
LM6142AI
LM6142BI
(Note 5)
Limit
Limit
(Note 6)
(Note 6)
1.3
Input Bias Current
Units
2
3.8
mV
4.8
4.8
max
174
nA
max
IOS
Input Offset Current
5
nA
max
RIN
Input Resistance
288
MΩ
CMRR
Common Mode
0V ≤ VCM ≤ 23V
114
Rejection Ratio
0V ≤ VCM ≤ 24V
100
dB
min
Power Supply
0V ≤ VCM ≤ 24V
87
PSRR
Rejection Ratio
VCM
AV
Input Common-Mode
−0.25
0
0
V min
Voltage Range
24.25
24
24
V max
Large Signal
RL = 10k
500
RL = 10 kΩ
0.07
V/mV
Voltage Gain
VO
Output Swing
min
23.85
IS
GBW
Supply Current
Gain-Bandwidth Product
Per Amplifier
750
f = 50 kHz
18
0.15
0.15
V
0.185
0.185
max
23.81
23.81
V
23.62
23.62
min
1100
1100
µA
1150
1150
max
MHz
Note 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 guaranteed. For guaranteed specifications and the test conditions, see the Electrical Charactenstics.
Note 2: Human body model, 1.5 kΩ in series with 100 pF.
Note 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.
Note 4: 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.
Note 5: Typical values represent the most likely parametric norm.
Note 6: All limits are guaranteed by testing or statistical analysis.
Note 7: For guaranteed military specifications see military datasheet MNLM6142AM-X.
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6
Typical Performance Characteristics
Supply Current vs
Supply Voltage
TA = 25˚C, RL = 10 kΩ Unless Otherwise Specified
Offset Voltage vs
Supply Voltage
Bias Current vs
Supply Voltage
DS012057-15
Offset Voltage vs VCM
DS012057-16
Offset Voltage vs VCM
DS012057-18
Bias Current vs VCM
Offset Voltage vs VCM
DS012057-19
Bias Current vs VCM
DS012057-21
Open-Loop Transfer
Function
DS012057-17
DS012057-20
Bias Current vs VCM
DS012057-22
Open-Loop Transfer
Function
DS012057-24
Open-Loop Transfer
Function
DS012057-25
7
DS012057-23
DS012057-26
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Typical Performance Characteristics
TA = 25˚C, RL = 10 kΩ Unless Otherwise
Specified (Continued)
Output Voltage vs
Source Current
Output Voltage vs
Source Current
DS012057-27
Output Voltage vs
Sink Current
Output Voltage vs
Source Current
DS012057-28
Output Voltage vs
Sink Current
DS012057-30
Gain and Phase vs Load
DS012057-29
Output Voltage vs
Sink Current
DS012057-31
Gain and Phase vs Load
DS012057-33
DS012057-32
Distortion + Noise
vs Frequency
DS012057-34
DS012057-35
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8
Typical Performance Characteristics
TA = 25˚C, RL = 10 kΩ Unless Otherwise
Specified (Continued)
Open Loop Gain vs
Load, 3V Supply
GBW vs Supply
Open Loop Gain vs
Load, 5V Supply
DS012057-36
DS012057-37
Open Loop Gain vs
Load, 24V Supply
DS012057-38
CMRR vs Frequency
Unity Gain Freq vs VS
DS012057-40
DS012057-41
DS012057-39
Crosstalk vs Frequency
PSRR vs Frequency
Noise Voltage vs Frequency
DS012057-43
DS012057-42
9
DS012057-44
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Typical Performance Characteristics
TA = 25˚C, RL = 10 kΩ Unless Otherwise
Specified (Continued)
Noise Current vs Frequency
NE vs R Source
DS012057-12
DS012057-45
LM6142/44 Application Ideas
Slew Rate vs ∆ VIN
VS = ± 5V
The LM6142 brings a new level of ease of use to opamp system design.
With greater than rail-to-rail input voltage range concern
over exceeding the common-mode voltage range is eliminated.
Rail-to-rail output swing provides the maximum possible dynamic range at the output. This is particularly important
when operating on low supply voltages.
The high gain-bandwidth with low supply current opens new
battery powered applications, where high power consumption, previously reduced battery life to unacceptable levels.
To take advantage of these features, some ideas should be
kept in mind.
ENHANCED SLEW RATE
Unlike most bipolar opamps, the unique phase reversal
prevention/speed-up circuit in the input stage causes the
slew rate to be very much a function of the input signal amplitude.
DS012057-7
FIGURE 1.
This effect is most noticeable at higher supply voltages and
lower gains where incoming signals are likely to be large.
This new input circuit also eliminates the phase reversal
seen in many opamps when they are overdriven.
This speed-up action adds stability to the system when driving large capacitive loads.
Figure 2 shows how excess input signal, is routed around
the input collector-base junctions, directly to the current mirrors.
The LM6142/44 input stage converts the input voltage
change to a current change. This current change drives the
current mirrors through the collectors of Q1–Q2, Q3–Q4
when the input levels are normal.
If the input signal exceeds the slew rate of the input stage,
the differential input voltage rises above two diode drops.
This excess signal bypasses the normal input transistors,
(Q1–Q4), and is routed in correct phase through the two additional transistors, (Q5, Q6), directly into the current mirrors.
This rerouting of excess signal allows the slew-rate to increase by a factor of 10 to 1 or more. (See Figure 1.)
As the overdrive increases, the opamp reacts better than a
conventional opamp. Large fast pulses will raise the slewrate to around 30V to 60V/µs.
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DRIVING CAPACITIVE LOADS
Capacitive loads decrease the phase margin of all opamps.
This is caused by the output resistance of the amplifier and
the load capacitance forming an R-C phase lag network.
This can lead to overshoot, ringing and oscillation. Slew rate
limiting can also cause additional lag. Most opamps with a
fixed maximum slew-rate will lag further and further behind
when driving capacitive loads even though the differential input voltage raises. With the LM6142, the lag causes the slew
rate to raise. The increased slew-rate keeps the output following the input much better. This effectively reduces phase
lag. After the output has caught up with the input, the differential input voltage drops down and the amplifier settles
rapidly.
10
LM6142/44 Application Ideas
(Continued)
DS012057-6
FIGURE 2.
These features allow the LM6142 to drive capacitive loads
as large as 1000 pF at unity gain and not oscillate. The
scope photos (Figure 3 and Figure 4) above show the
LM6142 driving a l000 pF load. In Figure 3, the upper trace
is with no capacitive load and the lower trace is with a 1000
pF load. Here we are operating on ± 12V supplies with a 20
Vp-p pulse. Excellent response is obtained with a Cf of l0 pF.
In Figure 4, the supplies have been reduced to ± 2.5V, the
pulse is 4 Vp-p and Cf is 39 pF. The best value for the compensation capacitor is best established after the board layout
is finished because the value is dependent on board stray
capacity, the value of the feedback resistor, the closed loop
gain and, to some extent, the supply voltage.
Another effect that is common to all opamps is the phase
shift caused by the feedback resistor and the input capacitance. This phase shift also reduces phase margin. This effect is taken care of at the same time as the effect of the capacitive load when the capacitor is placed across the
feedback resistor.
The circuit shown in Figure 5 was used for these scope
photos.
DS012057-9
FIGURE 4.
DS012057-10
FIGURE 5.
Typical Applications
DS012057-8
FISH FINDER/ DEPTH SOUNDER.
FIGURE 3.
The LM6142/44 is an excellent choice for battery operated
fish finders. The low supply current, high gain-bandwidth and
full rail to rail output swing of the LM6142 provides an ideal
combination for use in this and similar applications.
11
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Typical Applications
(Continued)
ANALOG TO DIGITAL CONVERTER BUFFER
The high capacitive load driving ability, rail-to-rail input and
output range with the excellent CMR of 82 dB, make the
LM6142/44 a good choice for buffering the inputs of A to D
converters.
3 OPAMP INSTRUMENTATION AMP WITH
RAIL-TO-RAIL INPUT AND OUTPUT
Using the LM6144, a 3 opamp instrumentation amplifier with
rail-to-rail inputs and rail to rail output can be made. These
features make these instrumentation amplifiers ideal for
single supply systems.
DS012057-13
Some manufacturers use a precision voltage divider array of
5 resistors to divide the common-mode voltage to get an input range of rail-to-rail or greater. The problem with this
method is that it also divides the signal, so to even get unity
gain, the amplifier must be run at high closed loop gains.
This raises the noise and drift by the internal gain factor and
lowers the input impedance. Any mismatch in these precision resistors reduces the CMR as well. Using the LM6144,
all of these problems are eliminated.
In this example, amplifiers A and B act as buffers to the differential stage (Figure 6). These buffers assure that the input
impedance is over 100 MΩ and they eliminate the requirement for precision matched resistors in the input stage. They
also assure that the difference amp is driven from a voltage
source. This is necessary to maintain the CMR set by the
matching of R1–R2 with R3–R4.
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FIGURE 6.
The gain is set by the ratio of R2/R1 and R3 should equal R1
and R4 equal R2. Making R4 slightly smaller than R2 and
adding a trim pot equal to twice the difference between R2
and R4 will allow the CMR to be adjusted for optimum.
With both rail to rail input and output ranges, the inputs and
outputs are only limited by the supply voltages. Remember
that even with rail-to-rail output, the output can not swing
past the supplies so the combined common mode voltage
plus the signal should not be greater than the supplies or limiting will occur.
SPICE MACROMODEL
A SPICE macromodel of this and many other National Semiconductor opamps is available at no charge from the NSC
Customer Response Group at 800-272-9959.
12
Physical Dimensions
inches (millimeters) unless otherwise noted
8-Pin Ceramic Sidebrazed
Dual-In-Line Package
Order Number LM6142AMJ-QML
NS Package Number D08C
8-Pin Small Outline Package
Order Number LM6142AIM or LM6142BIM
NS Package Number M08A
13
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Physical Dimensions
inches (millimeters) unless otherwise noted (Continued)
14-Pin Small Outline Package
Order Number LM6144AIM or LM6144BIM
NS Package Number M14A
8-Pin Molded Dual-In-Line Package
Order Number LM6142AIN or LM6142BIN
NS Package Number N08E
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14
inches (millimeters) unless otherwise noted (Continued)
14-Pin Molded Dual-In-Line Package
Order Number LM6144AIN or LM6144BIN
NS Package Number N14A
LIFE SUPPORT POLICY
NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT
DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL
COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein:
1. Life support devices or systems are devices or
systems which, (a) are intended for surgical implant
into the body, or (b) support or sustain life, and
whose failure to perform when properly used in
accordance with instructions for use provided in the
labeling, can be reasonably expected to result in a
significant injury to the user.
National Semiconductor
Corporation
Americas
Tel: 1-800-272-9959
Fax: 1-800-737-7018
Email: [email protected]
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Europe
Fax: +49 (0) 1 80-530 85 86
Email: [email protected]
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English Tel: +49 (0) 1 80-532 78 32
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2. A critical component is any component of a life
support device or system whose failure to perform
can be reasonably expected to cause the failure of
the life support device or system, or to affect its
safety or effectiveness.
National Semiconductor
Asia Pacific Customer
Response Group
Tel: 65-2544466
Fax: 65-2504466
Email: [email protected]
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Japan Ltd.
Tel: 81-3-5639-7560
Fax: 81-3-5639-7507
National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications.
LM6142 Dual and LM6144 Quad High Speed/Low Power 17 MHz Rail-to-Rail Input-Output
Operational Amplifiers
Physical Dimensions