LMP2014MT
www.ti.com
SNOSAK6B – DECEMBER 2004 – REVISED MARCH 2013
LMP2014MT Quad High Precision, Rail-to-Rail Output Operational Amplifier
Check for Samples: LMP2014MT
FEATURES
DESCRIPTION
•
•
•
•
•
•
•
•
•
•
•
The LMP2014MT is a member of Texas Instruments'
new LMPTM precision amplifier family. The
LMP2014MT offers unprecedented accuracy and
stability while also being offered at an affordable
price. This device utilizes patented techniques to
measure and continually correct the input offset error
voltage. The result is an amplifier which is ultra stable
over time and temperature. It has excellent CMRR
and PSRR ratings, and does not exhibit the familiar
1/f voltage and current noise increase that plagues
traditional amplifiers. The combination of the
LMP2014 characteristics makes it a good choice for
transducer amplifiers, high gain configurations, ADC
buffer amplifiers, DAC I-V conversion, and any other
2.7V-5V application requiring precision and long term
stability.
1
2
(For VS = 5V, Typical Unless Otherwise Noted)
Low Specified VOS Over Temperature 60 µV
Low Noise with No 1/f 35nV/√Hz
High CMRR 130 dB
High PSRR 120 dB
High AVOL 130 dB
Wide Gain-Bandwidth Product 3 MHz
High Slew Rate 4 V/µs
Low Supply Current 3.7 mA
Rail-to-Rail Output 30 mV
No External Capacitors Required
APPLICATIONS
•
•
•
Precision Instrumentation Amplifiers
Thermocouple Amplifiers
Strain Gauge Bridge Amplifier
Other useful benefits of the LMP2014 are rail-to-rail
output, a low supply current of 3.7 mA, and wide
gain-bandwidth product of 3 MHz. These extremely
versatile features found in the LMP2014 provide high
performance and ease of use.
Connection Diagram
Figure 1. 14-Pin TSSOP – Top View
See Package Number PW
1
2
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.
All 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 © 2004–2013, Texas Instruments Incorporated
LMP2014MT
SNOSAK6B – DECEMBER 2004 – REVISED MARCH 2013
www.ti.com
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.
Absolute Maximum Ratings (1) (2)
ESD Tolerance
Human Body Model
2000V
Machine Model
200V
Supply Voltage
5.8V
−0.3 ≤ VCM ≤ VCC +0.3V
Common-Mode Input Voltage
Lead Temperature (soldering 10 sec.)
+300°C
Differential Input Voltage
±Supply Voltage
Current at Input Pin
30 mA
Current at Output Pin
30 mA
Current at Power Supply Pin
50 mA
(1)
(2)
Absolute Maximum Ratings indicate limits beyond which damage may occur. Operating Ratings indicate conditions for which the device
is intended to be functional, but specific performance is not ensured. For ensured specifications and test conditions, see the Electrical
Characteristics.
If Military/Aerospace specified devices are required, please contact the TI Sales Office/ Distributors for availability and specifications.
Operating Ratings (1)
Supply Voltage
2.7V to 5.25V
−65°C to 150°C
Storage Temperature Range
Operating Temperature Range
(1)
LMP2014MT, LMP2014MTX
0°C to 70°C
Absolute Maximum Ratings indicate limits beyond which damage may occur. Operating Ratings indicate conditions for which the device
is intended to be functional, but specific performance is not ensured. For ensured specifications and test conditions, see the Electrical
Characteristics.
2.7V DC Electrical Characteristics
Unless otherwise specified, all limits specified for T J = 25°C, V+ = 2.7V, V-= 0V, V CM = 1.35V, VO = 1.35V and RL > 1 MΩ.
Boldface limits apply at the temperature extremes.
Symbol
VOS
TCVOS
Typ (2)
Max (1)
Units
Input Offset Voltage
0.8
30
60
μV
Offset Calibration Time
0.5
10
12
ms
Parameter
Conditions
Min (1)
Input Offset Voltage
0.015
μV/°C
Long-Term Offset Drift
0.006
μV/month
Lifetime VOS Drift
2.5
μV
IIN
Input Current
-3
pA
IOS
Input Offset Current
6
pA
RIND
Input Differential Resistance
CMRR
Common Mode Rejection Ratio
PSRR
Power Supply Rejection Ratio
AVOL
Open Loop Voltage Gain
(1)
(2)
2
9
MΩ
95
90
130
dB
95
90
120
dB
RL = 10 kΩ
95
90
130
RL = 2 kΩ
90
85
124
−0.3 ≤ VCM ≤ 0.9V
0 ≤ VCM ≤ 0.9V
dB
Limits are 100% production tested at 25°C. Limits over the operating temperature range are specified through correlations using
statistical quality control (SQC) method.
Typical values represent the most likely parametric norm.
Submit Documentation Feedback
Copyright © 2004–2013, Texas Instruments Incorporated
Product Folder Links: LMP2014MT
LMP2014MT
www.ti.com
SNOSAK6B – DECEMBER 2004 – REVISED MARCH 2013
2.7V DC Electrical Characteristics (continued)
Unless otherwise specified, all limits specified for T J = 25°C, V+ = 2.7V, V-= 0V, V CM = 1.35V, VO = 1.35V and RL > 1 MΩ.
Boldface limits apply at the temperature extremes.
Symbol
VO
Parameter
Output Swing
Conditions
RL = 10 kΩ to 1.35V
VIN(diff) = ±0.5V
Min (1)
Typ (2)
2.63
2.655
2.68
0.033
RL = 2 kΩ to 1.35V
VIN(diff) = ±0.5V
2.615
2.615
Output Current
IS
Sourcing, VO = 0V
VIN(diff) = ±0.5V
5
3
12
Sinking, VO = 5V
VIN(diff) = ±0.5V
5
3
18
Supply Current per Channel
Units
V
0.070
0.075
2.65
0.061
IO
Max (1)
0.919
V
0.085
0.105
mA
1.20
1.50
mA
2.7V AC Electrical Characteristics
TJ = 25°C, V+ = 2.7V, V -= 0V, VCM = 1.35V, VO = 1.35V, and RL > 1 MΩ. Boldface limits apply at the temperature extremes.
Symbol
Parameter
Conditions
Min (1)
Typ (2)
Max
(1)
Units
GBW
Gain-Bandwidth Product
3
MHz
SR
Slew Rate
4
V/μs
θm
Phase Margin
60
Deg
Gm
Gain Margin
−14
dB
en
Input-Referred Voltage Noise
35
nV/√Hz
in
Input-Referred Current Noise
enp-p
Input-Referred Voltage Noise
trec
Input Overload Recovery Time
(1)
(2)
pA/√Hz
RS = 100Ω, DC to 10 Hz
850
nVpp
50
ms
Limits are 100% production tested at 25°C. Limits over the operating temperature range are specified through correlations using
statistical quality control (SQC) method.
Typical values represent the most likely parametric norm.
5V DC Electrical Characteristics
Unless otherwise specified, all limits specified for T J = 25°C, V+ = 5V, V-= 0V, V CM = 2.5V, VO = 2.5V and RL > 1MΩ.
Boldface limits apply at the temperature extremes.
Symbol
VOS
TCVOS
Typ (2)
Max (1)
Units
Input Offset Voltage
0.12
30
60
μV
Offset Calibration Time
0.5
10
12
ms
Parameter
Conditions
Min (1)
Input Offset Voltage
0.015
μV/°C
Long-Term Offset Drift
0.006
μV/month
Lifetime VOS Drift
2.5
μV
IIN
Input Current
-3
pA
IOS
Input Offset Current
6
pA
RIND
Input Differential Resistance
9
MΩ
CMRR
Common Mode Rejection Ratio
130
dB
(1)
(2)
−0.3 ≤ VCM ≤ 3.2
0 ≤ VCM ≤ 3.2
100
90
Limits are 100% production tested at 25°C. Limits over the operating temperature range are specified through correlations using
statistical quality control (SQC) method.
Typical values represent the most likely parametric norm.
Submit Documentation Feedback
Copyright © 2004–2013, Texas Instruments Incorporated
Product Folder Links: LMP2014MT
3
LMP2014MT
SNOSAK6B – DECEMBER 2004 – REVISED MARCH 2013
www.ti.com
5V DC Electrical Characteristics (continued)
Unless otherwise specified, all limits specified for T J = 25°C, V+ = 5V, V-= 0V, V CM = 2.5V, VO = 2.5V and RL > 1MΩ.
Boldface limits apply at the temperature extremes.
Symbol
PSRR
Power Supply Rejection Ratio
AVOL
Open Loop Voltage Gain
VO
Min (1)
Typ (2)
95
90
120
RL = 10 kΩ
105
100
130
RL = 2 kΩ
95
90
132
4.92
4.95
4.978
Parameter
Output Swing
Conditions
RL = 10 kΩ to 2.5V
VIN(diff) = ±0.5V
0.040
RL = 2 kΩ to 2.5V
VIN(diff) = ±0.5V
4.875
4.875
Output Current
IS
Sourcing, VO = 0V
VIN(diff) = ±0.5V
8
6
15
Sinking, VO = 5V
V IN(diff) = ±0.5V
8
6
17
Supply Current per Channel
Units
dB
dB
V
0.080
0.085
4.919
0.091
IO
Max (1)
0.930
V
0.125
0.140
mA
1.20
1.50
mA
5V AC Electrical Characteristics
TJ = 25°C, V+ = 5V, V -= 0V, VCM = 2.5V, VO = 2.5V, and RL > 1MΩ. Boldface limits apply at the temperature extremes.
Symbol
Parameter
GBW
Gain-Bandwidth Product
SR
θm
Conditions
Min (1)
Typ (2)
Max (1)
Units
3
MHz
Slew Rate
4
V/μs
Phase Margin
60
deg
Gm
Gain Margin
−15
dB
en
Input-Referred Voltage Noise
35
nV/√Hz
in
Input-Referred Current Noise
enp-p
Input-Referred Voltage Noise
trec
Input Overload Recovery Time
(1)
(2)
4
pA/√Hz
RS = 100Ω, DC to 10 Hz
850
nVPP
50
ms
Limits are 100% production tested at 25°C. Limits over the operating temperature range are specified through correlations using
statistical quality control (SQC) method.
Typical values represent the most likely parametric norm.
Submit Documentation Feedback
Copyright © 2004–2013, Texas Instruments Incorporated
Product Folder Links: LMP2014MT
LMP2014MT
www.ti.com
SNOSAK6B – DECEMBER 2004 – REVISED MARCH 2013
Typical Performance Characteristics
TA=25C, VS= 5V unless otherwise specified.
Supply Current vs. Supply Voltage
Offset Voltage vs. Supply Voltage
Figure 2.
Figure 3.
Offset Voltage vs. Common Mode
Offset Voltage vs. Common Mode
Figure 4.
Figure 5.
Voltage Noise vs. Frequency
Input Bias Current vs. Common Mode
500
10000
VS = 5V
400
300
BIAS CURRENT (pA)
VOLTAGE NOISE (nV/ Hz)
VS = 5V
1000
100
200
100
0
-100
-200
-300
-400
10
0.1
1
10
100
1k
10k 100k
1M
-500
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0
VCM (V)
FREQUENCY (Hz)
Figure 6.
Figure 7.
Submit Documentation Feedback
Copyright © 2004–2013, Texas Instruments Incorporated
Product Folder Links: LMP2014MT
5
LMP2014MT
SNOSAK6B – DECEMBER 2004 – REVISED MARCH 2013
www.ti.com
Typical Performance Characteristics (continued)
TA=25C, VS= 5V unless otherwise specified.
PSRR vs. Frequency
PSRR vs. Frequency
120
120
VS = 2.7V
100
80
VCM = 2.5V
100
80
NEGATIVE
PSRR
(dB)
PSRR
(dB)
VS = 5V
VCM = 1V
60
40
NEGATIVE
60
40
POSITIVE
POSITIVE
20
20
0
0
10
100
1k
10k
100k
1M
10M
FREQUENCY (Hz)
6
10
100
1k
10k
100k
1M
10M
FREQUENCY (Hz)
Figure 8.
Figure 9.
Output Sourcing @ 2.7V
Output Sourcing @ 5V
Figure 10.
Figure 11.
Output Sinking @ 2.7V
Output Sinking @ 5V
Figure 12.
Figure 13.
Submit Documentation Feedback
Copyright © 2004–2013, Texas Instruments Incorporated
Product Folder Links: LMP2014MT
LMP2014MT
www.ti.com
SNOSAK6B – DECEMBER 2004 – REVISED MARCH 2013
Typical Performance Characteristics (continued)
TA=25C, VS= 5V unless otherwise specified.
Max Output Swing vs. Supply Voltage
Max Output Swing vs. Supply Voltage
Figure 14.
Figure 15.
Min Output Swing vs. Supply Voltage
Min Output Swing vs. Supply Voltage
Figure 16.
Figure 17.
CMRR vs. Frequency
Open Loop Gain and Phase vs. Supply Voltage
100
140
150.0
VS = 5V
VS = 5V
120
80
120.0
PHASE
80
60
90.0
60.0
40
GAIN
30.0
20
40
PHASE (°)
VS = 5V
60
GAIN (dB)
CMRR (dB)
100
RL = 1M
0
20
0.0
VS = 2.7V
CL = < 20pF
VS = 2.7V OR 5V
-20
0
10
100
100k
1k
FREQUENCY (Hz)
100k
100
1k
10k
100k
1M
-30.0
10M
FREQUENCY (Hz)
Figure 18.
Figure 19.
Submit Documentation Feedback
Copyright © 2004–2013, Texas Instruments Incorporated
Product Folder Links: LMP2014MT
7
LMP2014MT
SNOSAK6B – DECEMBER 2004 – REVISED MARCH 2013
www.ti.com
Typical Performance Characteristics (continued)
TA=25C, VS= 5V unless otherwise specified.
Open Loop Gain and Phase vs. RL @ 2.7V
100
Open Loop Gain and Phase vs. RL @ 5V
150.0
100
120.0
80
150.0
RL = >1M
80
120.0
PHASE
PHASE
60.0
RL = >1M
40
30.0
20
VS = 5V
VS = 2.7V
0.0
CL = < 20 pF
RL = >1M & 2k
100k
10k
1M
100
100k
10k
1k
FREQUENCY (Hz)
Figure 21.
Open Loop Gain and Phase vs. CL @ 5V
150.0
100
150.0
20 pF
20 pF
80
120.0
80
120.0
PHASE
PHASE
500 pF
60.0
40
GAIN
30.0
20
CL = 20,50,200 & 500 pF
100k
10k
1k
1M
60.0
500 pF
GAIN
0
30.0
0.0
VS = 5V, RL = >1M
500 pF
500 pF
-20
40
CL = 20,50,200 & 500 pF
-20
100
1M
1k
10k
100k
FREQUENCY (Hz)
-30.0
10M
FREQUENCY (Hz)
Figure 22.
Open Loop Gain and Phase vs. Temperature @ 5V
113
100
113
100
PHASE
PHASE
90
0°C
80
90
0°C
0°C
45
20
70°C
VS = 2.7V
23
68
60
GAIN (dB)
GAIN
70°C
PHASE (deg)
GAIN (dB)
0°C
68
60
25°C
GAIN
40
70°C
20
0
0
CL = 1M
CL = 1M
1k
45
25°C
VOUT = 200mVPP
0
-30.0
10M
Figure 23.
Open Loop Gain and Phase vs. Temperature @ 2.7V
40
90.0
20
0.0
VS = 2.7V, RL = >1M
20 pF
60
90.0
GAIN (dB)
20 pF
PHASE (°)
GAIN (dB)
60
80
1M
Figure 20.
Open Loop Gain and Phase vs. CL @ 2.7V
100
-30.0
10M
-20
FREQUENCY (Hz)
100
0
0.0
PHASE (°)
1k
RL = 2k
CL = < 20 pF
RL = >1M & 2k
-30.0
10M
-20
100
0
RL = 2k
PHASE (deg)
0
60.0
RL = >1M
GAIN
30.0
20
90.0
PHASE (°)
RL = >1M
GAIN (dB)
GAIN (dB)
GAIN
40
60
90.0
PHASE (°)
RL = 2k
60
Figure 25.
Submit Documentation Feedback
Copyright © 2004–2013, Texas Instruments Incorporated
Product Folder Links: LMP2014MT
LMP2014MT
www.ti.com
SNOSAK6B – DECEMBER 2004 – REVISED MARCH 2013
Typical Performance Characteristics (continued)
TA=25C, VS= 5V unless otherwise specified.
THD+N vs. AMPL
THD+N vs. Frequency
10
10
MEAS FREQ = 1 KHz
MEAS BW = 22 KHz
VOUT = 2 VPP
MEAS BW = 500 kHz
RL = 10k
RL = 10k
1
AV = +10
1
THD+N (%)
THD+N (%)
AV = +10
VS = 2.7V
0.1
VS = 2.7V
VS = 5V
0.1
VS = 5V
VS = 5V
VS = 2.7V
0.01
0.1
0.01
1
10
10
100
1k
10k
OUTPUT VOLTAGE (VPP)
FREQUENCY (Hz)
Figure 26.
Figure 27.
100k
NOISE (200 nV/DIV)
0.1 Hz − 10 Hz Noise vs. Time
1 sec/DIV
Figure 28.
Submit Documentation Feedback
Copyright © 2004–2013, Texas Instruments Incorporated
Product Folder Links: LMP2014MT
9
LMP2014MT
SNOSAK6B – DECEMBER 2004 – REVISED MARCH 2013
www.ti.com
APPLICATION INFORMATION
THE BENEFITS OF LMP2014 NO 1/f NOISE
Using patented methods, the LMP2014 eliminates the 1/f noise present in other amplifiers. That noise, which
increases as frequency decreases, is a major source of measurement error in all DC-coupled measurements.
Low-frequency noise appears as a constantly-changing signal in series with any measurement being made. As a
result, even when the measurement is made rapidly, this constantly-changing noise signal will corrupt the result.
The value of this noise signal can be surprisingly large. For example: If a conventional amplifier has a flat-band
noise level of 10nV/√Hz and a noise corner of 10 Hz, the RMS noise at 0.001 Hz is 1µV/√Hz. This is equivalent
to a 0.50 µV peak-to-peak error, in the frequency range 0.001 Hz to 1.0 Hz. In a circuit with a gain of 1000, this
produces a 0.50 mV peak-to-peak output error. This number of 0.001 Hz might appear unreasonably low, but
when a data acquisition system is operating for 17 minutes, it has been on long enough to include this error. In
this same time, the LMP2014 will only have a 0.21 mV output error. This is smaller by 2.4 x. Keep in mind that
this 1/f error gets even larger at lower frequencies. At the extreme, many people try to reduce this error by
integrating or taking several samples of the same signal. This is also doomed to failure because the 1/f nature of
this noise means that taking longer samples just moves the measurement into lower frequencies where the noise
level is even higher.
The LMP2014 eliminates this source of error. The noise level is constant with frequency so that reducing the
bandwidth reduces the errors caused by noise.
Another source of error that is rarely mentioned is the error voltage caused by the inadvertent thermocouples
created when the common "Kovar type" IC package lead materials are soldered to a copper printed circuit board.
These steel-based leadframe materials can produce over 35 μV/°C when soldered onto a copper trace. This can
result in thermocouple noise that is equal to the LMP2014 noise when there is a temperature difference of only
0.0014°C between the lead and the board!
For this reason, the lead-frame of the LMP2014 is made of copper. This results in equal and opposite junctions
which cancel this effect.
OVERLOAD RECOVERY
The LMP2014 recovers from input overload much faster than most chopper-stabilized op amps. Recovery from
driving the amplifier to 2X the full scale output, only requires about 40 ms. Many chopper-stabilized amplifiers will
take from 250 ms to several seconds to recover from this same overload. This is because large capacitors are
used to store the unadjusted offset voltage.
Figure 29.
The wide bandwidth of the LMP2014 enhances performance when it is used as an amplifier to drive loads that
inject transients back into the output. ADCs (Analog-to-Digital Converters) and multiplexers are examples of this
type of load. To simulate this type of load, a pulse generator producing a 1V peak square wave was connected
to the output through a 10 pF capacitor. (Figure 29) The typical time for the output to recover to 1% of the
applied pulse is 80 ns. To recover to 0.1% requires 860ns. This rapid recovery is due to the wide bandwidth of
the output stage and large total GBW.
NO EXTERNAL CAPACITORS REQUIRED
The LMP2014 does not need external capacitors. This eliminates the problems caused by capacitor leakage and
dielectric absorption, which can cause delays of several seconds from turn-on until the amplifier's error has
settled.
10
Submit Documentation Feedback
Copyright © 2004–2013, Texas Instruments Incorporated
Product Folder Links: LMP2014MT
LMP2014MT
www.ti.com
SNOSAK6B – DECEMBER 2004 – REVISED MARCH 2013
MORE BENEFITS
The LMP2014 offers the benefits mentioned above and more. It has a rail-to-rail output and consumes only 950
µA of supply current while providing excellent DC and AC electrical performance. In DC performance, the
LMP2014 achieves 130 dB of CMRR, 120 dB of PSRR and 130 dB of open loop gain. In AC performance, the
LMP2014 provides 3 MHz of gain-bandwidth product and 4 V/µs of slew rate.
HOW THE LMP2014 WORKS
The LMP2014 uses new, patented techniques to achieve the high DC accuracy traditionally associated with
chopper-stabilized amplifiers without the major drawbacks produced by chopping. The LMP2014 continuously
monitors the input offset and corrects this error. The conventional chopping process produces many mixing
products, both sums and differences, between the chopping frequency and the incoming signal frequency. This
mixing causes large amounts of distortion, particularly when the signal frequency approaches the chopping
frequency. Even without an incoming signal, the chopper harmonics mix with each other to produce even more
trash. If this sounds unlikely or difficult to understand, look at the plot (Figure 30), of the output of a typical
(MAX432) chopper-stabilized op amp. This is the output when there is no incoming signal, just the amplifier in a
gain of -10 with the input grounded. The chopper is operating at about 150 Hz; the rest is mixing products. Add
an input signal and the noise gets much worse. Compare this plot with Figure 31 of the LMP2014. This data was
taken under the exact same conditions. The auto-zero action is visible at about 30 kHz but note the absence of
mixing products at other frequencies. As a result, the LMP2014 has very low distortion of 0.02% and very low
mixing products.
Figure 30.
10000
VOLTAGE NOISE (nV/ Hz)
VS = 5V
1000
100
10
0.1
1
10
100
1k
10k 100k
1M
FREQUENCY (Hz)
Figure 31.
Submit Documentation Feedback
Copyright © 2004–2013, Texas Instruments Incorporated
Product Folder Links: LMP2014MT
11
LMP2014MT
SNOSAK6B – DECEMBER 2004 – REVISED MARCH 2013
www.ti.com
INPUT CURRENTS
The LMP2014's input currents are different than standard bipolar or CMOS input currents in that it appears as a
current flowing in one input and out the other. Under most operating conditions, these currents are in the
picoamp level and will have little or no effect in most circuits. These currents tend to increase slightly when the
common-mode voltage is near the minus supply. (See the typical curves.) At high temperatures such as 70°C,
the input currents become larger, 0.5 nA typical, and are both positive except when the VCM is near V−. If
operation is expected at low common-mode voltages and high temperature, do not add resistance in series with
the inputs to balance the impedances. Doing this can cause an increase in offset voltage. A small resistance
such as 1 kΩ can provide some protection against very large transients or overloads, and will not increase the
offset significantly.
PRECISION STRAIN-GAUGE AMPLIFIER
This Strain-Gauge amplifier (Figure 32) provides high gain (1006 or ~60 dB) with very low offset and drift. Using
the resistors' tolerances as shown, the worst case CMRR will be greater than 108 dB. The CMRR is directly
related to the resistor mismatch. The rejection of common-mode error, at the output, is independent of the
differential gain, which is set by R3. The CMRR is further improved, if the resistor ratio matching is improved, by
specifying tighter-tolerance resistors, or by trimming.
5V
+
VOUT
+
R1
R2
10k, 0.1%
2k, 1%
R3
R2
R1
2k, 1%
10k, 0.1%
20:
Figure 32.
Extending Supply Voltages and Output Swing by Using a Composite Amplifier Configuration:
In cases where substantially higher output swing is required with higher supply voltages, arrangements like the
ones shown in Figure 33 and Figure 34 could be used. These configurations utilize the excellent DC performance
of the LMP2014 while at the same time allow the superior voltage and frequency capabilities of the LM6171 to
set the dynamic performance of the overall amplifier. For example, it is possible to achieve ±12V output swing
with 300 MHz of overall GBW (AV = 100) while keeping the worst case output shift due to VOS less than 4 mV.
The LMP2014 output voltage is kept at about mid-point of its overall supply voltage, and its input common mode
voltage range allows the V- terminal to be grounded in one case (Figure 33, inverting operation) and tied to a
small non-critical negative bias in another (Figure 34, non-inverting operation). Higher closed-loop gains are also
possible with a corresponding reduction in realizable bandwidth. Table 1 shows some other closed loop gain
possibilities along with the measured performance in each case.
12
Submit Documentation Feedback
Copyright © 2004–2013, Texas Instruments Incorporated
Product Folder Links: LMP2014MT
LMP2014MT
www.ti.com
SNOSAK6B – DECEMBER 2004 – REVISED MARCH 2013
C2
R2
R7, 3.9k
C4
0.01
PF
R1
Input
2
-
+15V
1N4733A
(5.1V)
D1
7
LMP201X
3 U1
+
4
3
7
+
LM6171
2 U2
4
6
6
Output
-15V
(+2.5V)
+15V
R3
R5, 1M
20k
R4
3.9k
C3
0.01 PF
Figure 33.
Table 1. Composite Amplifier Measured Performance
AV
R1
Ω
R2
Ω
C2
pF
BW
MHz
SR
(V/μs)
en p-p
(mVPP)
50
200
10k
8
3.3
178
37
100
100
10k
10
2.5
174
70
100
1k
100k
0.67
3.1
170
70
500
200
100k
1.75
1.4
96
250
1000
100
100k
2.2
0.98
64
400
Submit Documentation Feedback
Copyright © 2004–2013, Texas Instruments Incorporated
Product Folder Links: LMP2014MT
13
LMP2014MT
SNOSAK6B – DECEMBER 2004 – REVISED MARCH 2013
www.ti.com
In terms of the measured output peak-to-peak noise, the following relationship holds between output noise
voltage, en p-p, for different closed-loop gain, AV, settings, where −3 dB Bandwidth is BW:
C2
R2
R7, 3.9k
0.01
PF
R1
+15V
1N4731A
(4.3V)
D1
C4
2
7
LMP201X
3 U1
+
4
Input
3
6
-15V
R6
(-0.7V)
10k
+15V R3
C5
0.01 PF
7
+
LM6171
2 U2
4
Output
6
(+2.5V)
20k
D2
R4
1N4148 3.9k
R5, 1M
C3
0.01 PF
Figure 34.
It should be kept in mind that in order to minimize the output noise voltage for a given closed-loop gain setting,
one could minimize the overall bandwidth. As can be seen from Equation 1 above, the output noise has a
square-root relationship to the Bandwidth.
In the case of the inverting configuration, it is also possible to increase the input impedance of the overall
amplifier, by raising the value of R1, without having to increase the feed-back resistor, R2, to impractical values,
by utilizing a "Tee" network as feedback. See the LMC6442 Data Sheet (Application Notes section) for more
details on this.
+5V
+5V
-
VIN
+VREF
+Input
LMP201X
+
430:
(0V to 5V Range)
ADC1203X
-Input
-VREF
+2.5V
LM9140-2.5
GND
1M
Figure 35.
14
Submit Documentation Feedback
Copyright © 2004–2013, Texas Instruments Incorporated
Product Folder Links: LMP2014MT
LMP2014MT
www.ti.com
SNOSAK6B – DECEMBER 2004 – REVISED MARCH 2013
LMP2014 AS ADC INPUT AMPLIFIER
The LMP2014 is a great choice for an amplifier stage immediately before the input of an ADC (Analog-to-Digital
Converter), whether AC or DC coupled. See Figure 35 and Figure 36. This is because of the following important
characteristics:
a. Very low offset voltage and offset voltage drift over time and temperature allow a high closed-loop gain
setting without introducing any short-term or long-term errors. For example, when set to a closed-loop gain of
100 as the analog input amplifier for a 12-bit A/D converter, the overall conversion error over full operation
temperature and 30 years life of the part (operating at 50°C) would be less than 5 LSBs.
b. Fast large-signal settling time to 0.01% of final value (1.4 μs) allows 12 bit accuracy at 100 KHZ or more
sampling rate.
c. No flicker (1/f) noise means unsurpassed data accuracy over any measurement period of time, no matter
how long. Consider the following op amp performance, based on a typical low-noise, high-performance
commercially-available device, for comparison:
Op amp flatband noise = 8nV/√Hz
1/f corner frequency = 100 Hz
AV = 2000
Measurement time = 100 sec
Bandwidth = 2 Hz
This example will result in about 2.2 mVPP (1.9 LSB) of output noise contribution due to the op amp alone,
compared to about 594 μVPP (less than 0.5 LSB) when that op amp is replaced with the LMP2014 which has
no 1/f contribution. If the measurement time is increased from 100 seconds to 1 hour, the improvement
realized by using the LMP2014 would be a factor of about 4.8 times (2.86 mVPP compared to 596 μV when
LMP2014 is used) mainly because the LMP2014 accuracy is not compromised by increasing the observation
time.
d. Copper leadframe construction minimizes any thermocouple effects which would degrade low level/high gain
data conversion application accuracy (see discussion under " The Benefits of the LMP2014" section above).
e. Rail-to-Rail output swing maximizes the ADC dynamic range in 5-Volt single-supply converter applications.
Below are some typical block diagrams showing the LMP2014 used as an ADC amplifier.
Figure 36.
Submit Documentation Feedback
Copyright © 2004–2013, Texas Instruments Incorporated
Product Folder Links: LMP2014MT
15
LMP2014MT
SNOSAK6B – DECEMBER 2004 – REVISED MARCH 2013
www.ti.com
REVISION HISTORY
Changes from Revision A (March 2013) to Revision B
•
16
Page
Changed layout of National Data Sheet to TI format .......................................................................................................... 15
Submit Documentation Feedback
Copyright © 2004–2013, Texas Instruments Incorporated
Product Folder Links: LMP2014MT
PACKAGE OPTION ADDENDUM
www.ti.com
10-Dec-2020
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)
(4/5)
(6)
LMP2014MT/NOPB
ACTIVE
TSSOP
PW
14
94
RoHS & Green
SN
Level-1-260C-UNLIM
0 to 70
LMP20
14MT
LMP2014MTX/NOPB
ACTIVE
TSSOP
PW
14
2500
RoHS & Green
SN
Level-1-260C-UNLIM
0 to 70
LMP20
14MT
(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
