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LM6142
Technical data
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National Semiconductor LM6142, LM6144 Technical data

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November 2004
LM6142/LM6144 17 MHz Rail-to-Rail Input-Output Operational Amplifiers
LM6142/LM6144, 17 MHz Rail-to-Rail Input-Output Operational Amplifiers

General Description

Using patent pending new circuit topologies, the LM6142/ LM6144 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/LM6144 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 650µA/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.

Connection Diagrams

8-Pin CDIP 8-Pin DIP/SO

Features

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: 17MHz at 50kHz (typ) n Slew rate:
Small signal, 5V/µs Large signal, 30V/µs
n Low supply current 650µA/Amplifier n Wide supply range 1.8V to 24V n CMRR 107dB n Gain 108dB with R n PSRR 87dB
= 10k
L

Applications

n Battery operated instrumentation n Depth sounders/fish finders n Barcode scanners n Wireless communications n Rail-to-rail in-out instrumentation amps
Top View
© 2004 National Semiconductor Corporation DS012057 www.national.com
01205714
Top View
14-Pin DIP/SO
01205702
Top View
01205701

Absolute Maximum Ratings (Note 1)

If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications.
ESD Tolerance (Note 2) 2500V
LM6142/LM6144
Differential Input Voltage 15V
Voltage at Input/Output Pin (V
Supply Voltage (V
+−V−
) 35V
Current at Input Pin
Current at Output Pin (Note 3)
Current at Power Supply Pin 50mA
Lead Temperature
+
) + 0.3V, (V−) − 0.3V
±
10mA
±
25mA

Operating Ratings (Note 1)

Supply Voltage 1.8V ≤ V
Temperature Range
LM6142, LM6144 −40˚C ≤ T
Thermal Resistance (θ
N Package, 8-Pin Molded DIP 115˚C/W
M Package, 8-Pin Surface
Mount 193˚C/W
N Package, 14-Pin Molded
DIP 81˚C/W
M Package, 14-Pin Surface
Mount 126˚C/W
)
JA
(soldering, 10 sec) 260˚C
Storage Temp. Range −65˚C to +150˚C
Junction Temperature (Note 4) 150˚C

5.0V DC Electrical Characteristics (Note 8)

Unless otherwise specified, all limits guaranteed for TA= 25˚C, V+= 5.0V, V−= 0V, VCM=VO=V+/2 and R
Boldface limits apply at the temperature extremes.
LM6144AI LM6144BI
Symbol Parameter Conditions Typ LM6142AI LM6142BI Units
(Note 5) Limit Limit
(Note 6) (Note 6)
V
OS
Input Offset Voltage 0.3 1.0 2.5 mV
2.2 3.3 max
TCV
OS
Input Offset Voltage 3 µV/˚C
Average Drift
I
B
Input Bias Current 170 250 300 nA
0V ≤ V
≤ 5V 180 280
CM
526 526
I
OS
Input Offset Current 3 30 30 nA
80 80 max
R
IN
CMRR Common Mode 0V ≤ V
Input Resistance, C
M
≤ 4V 107 84 84
CM
126 MΩ
Rejection Ratio 78 78
0V ≤ V
≤ 5V 82 66 66
CM
79 64 64
PSRR Power Supply 5V ≤ V
+
≤ 24V 87 80 80
Rejection Ratio 78 78
V
CM
Input Common-Mode −0.25 00V
Voltage Range 5.25 5.0 5.0
A
V
Large Signal RL= 10k 270 100 80 V/mV
Voltage Gain 70 33 25 min
V
O
Output Swing RL= 100k 0.005 0.01 0.01 V
0.013 0.013 max
4.995 4.98 4.98 V
4.93 4.93 min
R
= 10k 0.02 V max
L
4.97 V min
R
= 2k 0.06 0.1 0.1 V
L
0.133 0.133 max
4.90 4.86 4.86 V
L
+
≤ 24V
≤ +85˚C
A
>
1MΩ to V+/2.
max
dB
min
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5.0V DC Electrical Characteristics (Note 8) (Continued)
Unless otherwise specified, all limits guaranteed for TA= 25˚C, V+= 5.0V, V−= 0V, VCM=VO=V+/2 and R
Boldface limits apply at the temperature extremes.
LM6144AI LM6144BI
Symbol Parameter Conditions Typ LM6142AI LM6142BI Units
(Note 5) Limit Limit
(Note 6) (Note 6)
4.80 4.80 min
I
SC
Output Short Sourcing 13 10 8 mA
Circuit Current 4.9 4 min
LM6142 35 35 mA
Sinking 24 10 10 mA
5.3 5.3 min
35 35 mA
I
SC
Output Short Sourcing 8 6 6 mA
Circuit Current 33min
LM6144 35 35 mA
Sinking 22 8 8 mA
44min
35 35 mA
I
S
Supply Current Per Amplifier 650 800 800 µA
880 880 max
>
1MΩ to V+/2.
L
LM6142/LM6144
max
max
max
max

5.0V AC Electrical Characteristics (Note 8)

Unless Otherwise Specified, All Limits Guaranteed for TA= 25˚C, V+= 5.0V, V−= 0V, VCM=VO=V+/2 and R
+
/2. Boldface limits apply at the temperature extremes.
V
LM6144AI LM6144BI
Symbol Parameter Conditions Typ LM6142AI LM6142BI Units
(Note 5) Limit Limit
(Note 6) (Note 6)
SR Slew Rate 8 V
@
V+12V 25 15 13 V/µs
PP
>
R
1kΩ 13 11 min
S
GBW Gain-Bandwidth Product f = 50 kHz 17 10 10 MHz
66min
φ
m
Phase Margin 38 Deg
Amp-to-Amp Isolation 130 dB
e
n
Input-Referred f=1kHz
16
Voltage Noise
i
n
Input-Referred f=1kHz
0.22
Current Noise
T.H.D. Total Harmonic Distortion f = 10 kHz, R
=10kΩ, 0.003 %
L
>
L
1MΩ to
www.national.com3

2.7V DC Electrical Characteristics (Note 8)

Unless Otherwise Specified, All Limits Guaranteed for TA= 25˚C, V+= 2.7V, V−= 0V, VCM=VO=V+/2 and R
+
/2. Boldface limits apply at the temperature extreme
V
LM6144AI LM6144BI
Symbol Parameter Conditions Typ LM6142AI LM6142BI Units
LM6142/LM6144
V
OS
I
B
I
OS
R
IN
CMRR Common Mode 0V ≤ V
PSRR Power Supply 3V ≤ V+ ≤ 5V 79
V
CM
A
V
V
O
I
S
Input Offset Voltage 0.4 1.8 2.5 mV
Input Bias Current 150 250 300 nA
Input Offset Current 4 30 30 nA
Input Resistance 128 MΩ
≤ 1.8V 90 dB
CM
Rejection Ratio 0V ≤ V
≤ 2.7V 76
CM
Rejection Ratio
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 min
Output Swing RL= 100kΩ 0.019 0.08 0.08 V
Supply Current Per Amplifier 510 800 800 µA
(Note 5) Limit Limit
(Note 6) (Note 6)
4.3 5 max
526 526 max
80 80 max
0.112 0.112 max
2.67 2.66 2.66 V
2.25 2.25 min
880 880 max
L
>
1MΩ to
min

2.7V AC Electrical Characteristics (Note 8)

Unless Otherwise Specified, All Limits Guaranteed for TA= 25˚C, V+= 2.7V, V−= 0V, VCM=VO=V+/2 and R
+
/2. Boldface limits apply at the temperature extreme
V
LM6144AI LM6144BI
Symbol Parameter Conditions Typ LM6142AI LM6142BI Units
(Note 5) Limit Limit
(Note 6) (Note 6)
GBW Gain-Bandwidth Product f = 50 kHz 9 MHz
φ
m
G
m
Phase Margin 36 Deg
Gain Margin 6 dB
L
>
1MΩ to
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24V Electrical Characteristics (Note 8)

Unless Otherwise Specified, All Limits Guaranteed for TA= 25˚C, V+= 24V, V−= 0V, VCM=VO=V+/2 and R
+
/2. Boldface limits apply at the temperature extreme
V
LM6144AI LM6144BI
Symbol Parameter Conditions Typ LM6142AI LM6142BI Units
(Note 5) Limit Limit
(Note 6) (Note 6)
V
OS
Input Offset Voltage 1.3 2 3.8 mV
4.8 4.8 max
I
B
I
OS
R
IN
CMRR Common Mode 0V ≤ V
PSRR Power Supply 0V ≤ V
Input Bias Current 174 nA
Input Offset Current 5 nA
Input Resistance 288 MΩ
≤ 23V 114 dB
CM
Rejection Ratio 0V ≤ V
≤ 24V 100
CM
≤ 24V 87
CM
Rejection Ratio
V
CM
Input Common-Mode −0.25 0 0 V min
Voltage Range 24.25 24 24 V max
A
V
Large Signal RL= 10k 500 V/mV
Voltage Gain min
V
O
Output Swing RL=10kΩ 0.07 0.15 0.15 V
0.185 0.185 max
23.85 23.81 23.81 V
23.62 23.62 min
I
S
Supply Current Per Amplifier 750 1100 1100 µA
1150 1150 max
GBW Gain-Bandwidth Product f = 50 kHz 18 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, 1.5kΩ in series with 100pF.
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 T (T
J(MAX)−TA
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.
Note 8: Electrical Table values apply only for factory testing conditions at the temperature indicated. Factory testing conditions result in very limited self-heating of
the device such that T TA.
)/θJA. All numbers apply for packages soldered directly into a PC board.
. No guarantee of parametric performance is indicated in the electrical tables under conditions of the internal self heating where T
J=TA
, θJA, and TA. The maximum allowable power dissipation at any ambient temperature is PD=
J(MAX)
>
L
1MΩ to
max
max
min
LM6142/LM6144
>
J
www.national.com5

Typical Performance Characteristics T

Supply Current vs. Supply Voltage Offset Voltage vs. Supply Voltage
LM6142/LM6144
01205715 01205716
Bias Current vs. Supply Voltage Offset Voltage vs. V
= 25˚C, RL=10kΩ Unless Otherwise Specified
A
CM
Offset Voltage vs. V
01205717 01205718
CM
01205719
Offset Voltage vs. V
CM
01205720
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LM6142/LM6144
Typical Performance Characteristics T
Specified (Continued)
Bias Current vs. V
Bias Current vs. V
CM
01205721 01205722
CM
= 25˚C, RL=10kΩ Unless Otherwise
A
Bias Current vs. V
Open-Loop Transfer Function
CM
01205723 01205724
Open-Loop Transfer Function Open-Loop Transfer Function
01205725 01205726
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Typical Performance Characteristics T
Specified (Continued)
Output Voltage vs. Source Current Output Voltage vs. Source Current
LM6142/LM6144
01205727 01205729
Output Voltage vs. Source Current Output Voltage vs. Sink Current
= 25˚C, RL=10kΩ Unless Otherwise
A
01205728 01205730
Output Voltage vs. Sink Current Output Voltage vs. Sink Current
01205731 01205732
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LM6142/LM6144
Typical Performance Characteristics T
Specified (Continued)
Gain and Phase vs. Load Gain and Phase vs. Load
01205733 01205734
Distortion + Noise vs. Frequency GBW vs. Supply
= 25˚C, RL=10kΩ Unless Otherwise
A
01205735
01205736
Open Loop Gain vs. Load, 3V Supply Open Loop Gain vs. Load, 5V Supply
01205737 01205738
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Typical Performance Characteristics T
Specified (Continued)
= 25˚C, RL=10kΩ Unless Otherwise
A
Open Loop Gain vs. Load, 24V Supply Unity Gain Frequency vs. V
LM6142/LM6144
01205739
CMRR vs. Frequency Crosstalk vs. Frequency
S
01205740
01205741 01205742
PSRR vs. Frequency Noise Voltage vs. Frequency
01205743 01205744
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LM6142/LM6144
Typical Performance Characteristics T
Specified (Continued)
Noise Current vs. Frequency NF vs. R
01205745

LM6142/LM6144 Application Ideas

The LM6142 brings a new level of ease of use to op amp 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.
= 25˚C, RL=10kΩ Unless Otherwise
A
Source
Slew Rate vs. ∆ V
VS=±5V
01205712
IN

ENHANCED SLEW RATE

Unlike most bipolar op amps, 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.
The LM6142/LM6144 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 op amp reacts better than a conventional op amp. Large fast pulses will raise the slew­rate to around 30V to 60V/µs.
01205707

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 op amps when they are overdriven.
This speed-up action adds stability to the system when driving large capacitive loads.

DRIVING CAPACITIVE LOADS

Capacitive loads decrease the phase margin of all op amps. 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 op amps 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.
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LM6142/LM6144 Application Ideas
(Continued)
LM6142/LM6144

FIGURE 2.

These features allow the LM6142 to drive capacitive loads as large as 1000pF at unity gain and not oscillate. The scope photos (Figure 3 and Figure 4) above show the LM6142 driving a l000pF load. In Figure 3, the upper trace is with no capacitive load and the lower trace is with a 1000pF load. Here we are operating on pulse. Excellent response is obtained with a Cfof l0pF. In Figure 4, the supplies have been reduced to pulse is 4 V
and Cfis 39pF. The best value for the
PP
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 op amps 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.
±
12V supplies with a 20 V
±
2.5V, the
01205709

FIGURE 4.

01205706
PP
01205710

FIGURE 5.

Typical Applications

FISH FINDER/ DEPTH SOUNDER.

The LM6142/LM6144 is an excellent choice for battery op­erated fish finders. The low supply current, high gain­bandwidth and full rail to rail output swing of the LM6142 provides an ideal combination for use in this and similar applications.

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/LM6144 a good choice for buffering the inputs of A to D converters.
01205708

FIGURE 3.

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3 OP AMP INSTRUMENTATION AMP WITH RAIL-TO-RAIL INPUT AND OUTPUT

Using the LM6144,a3opampinstrumentation 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.
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
LM6142/LM6144
Typical Applications (Continued)
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 100MΩ 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.
01205713

FIGURE 6.

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 op amps is available at no charge from the NSC Customer Response Group at 800-272-9959.

Ordering Information

Package Temperature Range Temperature Range NSC
Industrial Military
−40˚C to +85˚C −55˚C to +125˚C
8-Pin Molded DIP LM6142AIN N08E
LM6142BIN
8-Pin Small Outline LM6142AIM M08A
LM6142AIMX
LM6142BIM
LM6142BIMX
14-Pin Molded DIP LM6144AIN N14A
LM6144BIN
14-Pin Small Outline LM6144AIM M14A
LM6144AIMX
LM6144BIM
LM6144BIMX
8-Pin CDIP LM6142AMJ-QML J08A
Drawing
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Physical Dimensions inches (millimeters)

unless otherwise noted
LM6142/LM6144
8-Pin Cerdip
Dual-In-Line Package
NS Package Number J08A
8-Pin Small Outline Package
NS Package Number M08A
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Physical Dimensions inches (millimeters) unless otherwise noted (Continued)
LM6142/LM6144
14-Pin Small Outline Package
NS Package Number M14A
8-Pin Molded Dual-In-Line Package
NS Package Number N08E
www.national.com15
Physical Dimensions inches (millimeters) unless otherwise noted (Continued)
14-Pin Molded Dual-In-Line Package
NS Package Number N14A
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.
For the most current product information visit us at www.national.com.
LIFE SUPPORT POLICY
NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS
LM6142/LM6144, 17 MHz Rail-to-Rail Input-Output Operational Amplifiers
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
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.
provided in the labeling, can be reasonably expected to result in a significant injury to the user.
BANNED SUBSTANCE COMPLIANCE
National Semiconductor certifies that the products and packing materials meet the provisions of the Customer Products Stewardship Specification (CSP-9-111C2) and the Banned Substances and Materials of Interest Specification (CSP-9-111S2) and contain no ‘‘Banned Substances’’ as defined in CSP-9-111S2.
National Semiconductor Americas Customer Support Center
Email: new.feedback@nsc.com Tel: 1-800-272-9959
www.national.com
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Fax: +49 (0) 180-530 85 86
Email: europe.support@nsc.com Deutsch Tel: +49 (0) 69 9508 6208 English Tel: +44 (0) 870 24 0 2171 Français Tel: +33 (0) 1 41 91 8790
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