Page 1
LMV721/LMV722
10MHz, Low Noise, Low Voltage, and Low Power
Operational Amplifier
LMV721/LMV72210MHz, Low Noise, Low Voltage, and Low Power Operational Amplifier
August 1999
General Description
The LMV721 (Single) and LMV722 (Dual) are low noise, low
voltage, and low power op amps, that can be designed into
a wide range of applications. The LMV721/LMV722 has a
unity gain bandwidth of 10MHz, a slew rate of 5V/us, and a
quiescent current of 930uA/amplifier at 2.2V.
The LMV721/722 are designed to provide optimal performance in low voltage and low noise systems. They provide
rail-to-rail output swing into heavy loads. The input
common-mode voltage range includes ground, and the
maximum input offset voltage are 3.5mV (Over Temp.) for
the LMV721/LMV722. Their capacitive load capability is also
good at low supply voltages. The operating range is from
2.2V to 5.5V.
The chip is built with National’s advanced Submicron
Silicon-Gate BiCMOS process. The single version, LMV721,
is available in 5 pin SOT23-5 and a SC-70 (new) package.
The dual version, LMV722, is available in a SO-8 and
MSOP-8 package.
Connection Diagrams
5-Pin SC-70/SOT23-5
DS100922-99
Top View
Features
(For Typical, 5 V Supply Values; Unless Otherwise Noted)
n Guaranteed 2.2V and 5.0V Performance
n Low Supply Current LMV721/2 930µA/amplifier
n High Unity-Gain Bandwidth 10MHz
n Rail-to-Rail Output Swing
@
600Ω load 120mV from either rail at 2.2V
@
2kΩ load 50mV from either rail at 2.2V
n Input Common Mode Voltage Range Includes Ground
n Silicon Dust
n Input Voltage Noise 9
™
, SC70-5 Package 2.0x2.0x1.0 mm
@
f=1KHz
@
2.2V
Applications
n Cellular an Cordless Phones
n Active Filter and Buffers
n Laptops and PDAs
n Battery Powered Electronics
8-Pin SO/MSOP
DS100922-63
Top View
Silicon Dust™is a trademark of National Semiconductor Corporation.
© 1999 National Semiconductor Corporation DS100922 www.national.com
Page 2
Ordering Information
Temperature Range
Package
−40˚C to +85˚C
8-Pin Small Outline LMV722M LMV722M Rails
LMV722MX LMV722M 2.5K Units Tape and
8-pin MSOP LMV722MM LMV722 1K Units Tape and
LMV722MMX LMV722 3.5K Units Tape and
5-Pin SOT23 LMV721M5 A30A 1K Units Tape and
LMV721M5X A30A 3K Units Tape and
5-Pin SC-70 LMV721M7 A20 1K Units Tape and
LMV721M7X A20 3K Units Tape and
Packaging Marking Transport Media NSC DrawingIndustrial
Reel
Reel
Reel
Reel
Reel
Reel
Reel
M08A
MUA08A
M05B
MAA05A
www.national.com 2
Page 3
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)
Human Body Model 2000V
Machine Model 200V
Differential Input Voltage
Supply Voltage (V
+–V−
) 5.5V
±
Supply Voltage
Soldering Information
Infrared or Convection (20 sec.) 235˚C
Storage Temp. Range −65˚C to 150˚C
Junction Temperature (Note 4) 150˚C
Operating Ratings (Note 3)
Supply Voltage 2.2V to 5.0V
Temperature Range −40˚C ≤T
Thermal Resistance (θ
Silicon Dust SC70-5 Pkg 440 ˚C/W
Tiny SOT23-5 Pkg 265 ˚C/W
SO Pkg, 8-pin Surface Mount 190 ˚C/W
MSOP Pkg, 8-Pin Mini Surface
Mount
SO Pkge, 14-Pin Surface Mount 145 ˚C/W
)
JA
2.2V DC Electrical Characteristics
Unless otherwise specified, all limits guaranteed for TJ= 25˚C. V+= 2.2V, V−= 0V, VCM=V+/2, VO=V+/2 and R
Boldface limits apply at the temperature extremes.
Symbol Parameter Condition
V
OS
TCV
I
B
I
OS
CMRR Common Mode Rejection Ratio 0V ≤ V
PSRR Power Supply Rejection Ratio 2.2V ≤ V
Input Offset Voltage 0.02 3
Input Offset Voltage Average
OS
Drift
Input Bias Current 260 nA
Input Offset Current 25 nA
≤ 1.3V 88 70
CM
+
≤ 5V, V
O
Typ
(Note 5)
0.6 µV/˚C
=
=
0V
090 7064dB min
CM
Limit
(Note 6)
3.5
64
≤85˚C
J
235 ˚C/W
>
1MΩ.
L
Units
mV
max
dB min
V
CM
A
V
V
O
Input Common-Mode Voltage
Range
Large Signal Voltage Gain RL=600Ω
Output Swing RL= 600Ω to V+/2 2.125 2.090
For CMRR ≥ 50dB −0.30 V
1.3 V
= 0.75V to 2.00V
V
O
R
=2kΩ
L
= 0.50V to 2.10V
V
O
81 75
60
84 75
60
dB min
dB min
V min
2.065
0.061 0.110
V max
0.135
=2kΩto V+/2 2.177 2.150
R
L
0.026 0.050
2.125
V min
V max
0.075
I
O
I
S
Output Current Sourcing, VO=0V
(diff) =±0.5V
V
IN
Sinking, V
V
IN
= 2.2V
O
(diff) =±0.5V
Supply Current LMV721 0.93 1.2
14.9 10.0
5.0
23.8 15.0
5.0
1.5
LMV722 1.64 2.2
mA min
mA min
mA
max
2.6
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Page 4
2.2V AC Electrical Characteristics
Unless otherwise specified, all limits guaranteed for TJ= 25˚C. V+= 2.2V, V−= 0V, VCM=V+/2,
VO=V+/2 and R
Symbol Parameter Conditions
SR Slew Rate (Note 7) 4.9 V/µs
GBW Gain-Bandwdth Product 10 MHz
Φ
m
G
m
e
n
>
1MΩ.Boldface limits apply at the temperature extremes.
L
Typ
(Note 5)
Units
Phase Margin 67.4 Deg
Gain Margin −9.8 dB
Input-Referred Voltage Noise f = 1 kHz 9
i
n
THD Total Harmonic Distortion f = 1 kHz AV=1
Input-Referred Current Noise f = 1 kHz 0.3
= 600Ω,VO= 500 mV
R
L
PP
0.004
5V DC Electrical Characteristics
Unless otherwise specified, all limits guaranteed for TJ= 25˚C. V+= 5V, V−= 0V, VCM=V+/2, VO=V+/2 and R
Boldface limits apply at the temperature extremes.
Symbol Parameter Condition
V
OS
TCV
I
B
I
OS
CMRR Common Mode Rejection Ratio 0V ≤ V
PSRR Power Supply Rejection Ratio 2.2V ≤ V
V
CM
A
V
V
O
I
O
I
S
Input Offset Voltage −0.08 3
Input Offset Voltage Average
OS
Drift
Input Bias Current 260 nA
Input Offset Current 25 nA
≤ 4.1V 89 70
CM
+
≤ 5.0V, V
Input Common-Mode Voltage
For CMRR ≥ 50dB −0.30 V
Range
Large Signal Voltage Gain RL= 600Ω
= 0.75V to 4.80V
V
O
R
=2kΩ,
L
= 0.70V to 4.90V,
V
O
Output Swing RL= 600Ω to V+/2 4.882 4.840
=2kΩto V+/2 4.962 4.940
R
L
Output Current Sourcing, VO=0V
=
±
(diff)
(diff)
0.5V
=5V
O
=
±
0.5V
V
IN
Sinking, V
V
IN
Supply Current LMV721 1.03 1.4
LMV722 1.83 2.4
=
=
0V
O
090 7064dB min
CM
Typ
(Note 5)
(Note 6)
0.6 µV/˚C
4.1 V
87 80
94 85
0.105 0.160
0.046 0.080
52.6 25.0
23.7 15.0
Limit
3.5
64
70
70
4.140
0.185
4.915
0.105
12.0
8.5
1.7
2.8
L
>
%
1MΩ.
Units
mV
max
dB min
dB
min
dB
min
V min
V max
V min
V max
mA min
mA min
mA
max
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Page 5
5V AC Electrical Characteristics
Unless otherwise specified, all limits guaranteed for TJ= 25˚C. V+= 5V, V−= 0V, VCM=V+/2, VO=V+/2 and R
Boldface limits apply at the temperature extremes.
Symbol Parameter Conditions
Typ
(Note 5)
SR Slew Rate (Note 7) 5.25 V/µs
GBW Gain-Bandwdth Product 10.0 MHz
Φ
m
G
m
e
n
Phase Margin 72 Deg
Gain Margin −11 dB
Input-Related Voltage Noise f = 1 kHz 8.5
L
>
1MΩ.
Units
min
i
n
THD Total Harmonic Distortion f = 1kHz, AV=1
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 Characteristics.
Note 2: Human body model, 1.5 kΩ in series with 100 pF. Machine model, 200Ω 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. Output currents in excess of 30 mA over long term may adversely affect reliability.
Note 4: The maximum power dissipation is a function of T
=(T
P
D
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: Connected as voltage follower with 1V step input. Number specified is the slower of the positive and negative slew rate.
Input-Referred Current Noise f = 1 kHz 0.2
= 600Ω,VO=1V
R
L
, θJA, and TA. The maximum allowable power dissipation at any ambient temperature is
)/θJA. All numbers apply for packages soldered directly into a PC board.
J(max)
PP
0.001
%
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Page 6
Typical Performance characteristics
Supply Current vs.
Supply Voltage(LMV721)
DS100922-1
Sinking Current vs.
Output Voltage (V
S
=
2.2V)
DS100922-4
Sourcing Current vs.
Output Voltage (V
Sinking Current vs.
Output Voltage (V
S
=
=
S
2.2V)
DS100922-2
5V)
DS100922-5
Sourcing Current vs.
Output Voltage (V
Output Voltage Swing vs.
Supply Voltage(R
L
=
S
=
600Ω)
5V)
DS100922-3
DS100922-6
Output Voltage Swing
vs. Suppy Voltage
=
(R
2kΩ)
L
DS100922-7
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Input Offset Voltage vs.
Input Common-Mode Voltage
Range V
Input Offset Voltage vs.
=
2.2V
S
DS100922-8
Input Common-Mode Voltage
Range V
=
5V
S
DS100922-9
Page 7
Typical Performance characteristics (Continued)
Input Offset Voltage vs.
Supply Voltage(V
CM
+
=
V
DS100922-10
/2)
Input Voltage Noise vs. Frequency
DS100922-38
−PSRR vs. Frequency
Input Voltage vs. Output Voltage
=
(V
S
2.2V, R
=
2kΩ)
L
DS100922-11
Input Current Noise vs. Frequency
DS100922-32
CMRR vs. Frequency
Input Voltage vs. Output Voltage
=
5V, R
=
2kΩ))
L
DS100922-12
(V
S
+PSRR vs. Frequency
DS100922-13
Gain and Phase Margin vs.
Frequency (V
S
=
2.2V, R
600Ω)
L
DS100922-14
DS100922-45
DS100922-15
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Page 8
Typical Performance characteristics (Continued)
Gain and Phase Margin vs.
Frequency (V
=
5V, R
S
L
600Ω)
DS100922-16
Slew Rate vs.
Supply Voltage
Application Notes
1.0 Benefits of the LMV721/722 Size.
The small footprints of the LMV721/722 packages save
space on printed circuit boards, and enable the design of
smaller electronic products, such as cellular phones, pagers,
or other portable systems. The low profile of the
LMV721/722 make them possible to use in PCMCIA type III
cards.
Signal Integrity. Signals can pick up noise between the signal source and the amplifier. By using a physically smaller
amplifier package, the LMV721/722 can be placed closer to
the signal source, reducing noise pickup and increasing signal integrity.
Simplified Board Layout. These products help you to avoid
using long pc traces in your pc board layout. This means that
no additional components, such as capacitors and resistors,
are needed to filter out the unwanted signals due to the interference between the long pc traces.
Low Supply Current. These devices will help you to maximize battery life. They are ideal for battery powered systems.
Low Supply Voltage. National provides guaranteed performance at 2.2V and 5V. These guarantees ensure operation
throughout the battery lifetime.
Rail-to-Rail Output. Rail-to-rail output swing provides maximum possible dynamic range at the output. This is particularly important when operating on low supply voltages.
Input Includes Ground. Allows direct sensing near GND in
single supply operation.
Protection should be provided to prevent the input voltages
from going negative more than −0.3V (at 25˚C). An input
clamp diode with a resistor to the IC input terminal can be
used.
2.0 Capacitive Load Tolerance
The LMV721/722 can directly drive 4700pF in unity-gain
without oscillation. The unity-gain follower is the most sensitive configuration to capacitive loading. Direct capacitive
loading reduces the phase margin of amplifiers. The combination of the amplifier’s output impedance and the capacitive
load induces phase lag. This results in either an underdamped pulse response or oscillation. To drive a heavier capacitive load, circuit in
Figure 1
can be used.
THD vs.
Frequency
DS100922-17
DS100922-42
DS100922-18
FIGURE 1. Indirectly Driving A capacitive Load Using
Resistive Isolation
In
Figure 1
C
, the isolation resistor R
form a pole to increase stability by adding more phase
L
margin to the overall system. the desired performance depends on the value of R
value, the more stable V
waveform of
C
.
L
Figure 1
ISO
OUT
using 100kΩ for R
and the load capacitor
ISO
. The bigger the R
will be.
Figure 2
and 2000µF for
ISO
DS100922-31
resistor
ISO
is an output
FIGURE 2. Pulse Response of the LMV721 Circuit in
Figure 1
Figure 3
The circuit in
1
because it provides DC accuracy as well as AC stability. If
there were a load resistor in
voltage divided by R
ure 3
,RFprovides the DC accuracy by using feed-forward
techniques to connect V
ing the value of R
LMV721/722. C
phase margin by feeding the high frequency component of
is an improvement to the one in
Figure 1
and the load resistor. Instead, in
ISO
to RL. Caution is needed in choos-
IN
due to the input bias current of the
F
F
and R
serve to counteract the loss of
ISO
, the output would be
Figure
Fig-
the output signal back to the amplifier’s inverting input,
thereby preserving phase margin in the overall feedback
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Page 9
Application Notes (Continued)
loop. Increased capacitive drive is possible by increasing the
value of C
3.0 Input Bias Current Cancellation
The LMV721/722 family has a bipolar input stage. The typical input bias current of LMV721/722 is 260nA with 5V supply. Thus a 100kΩ input resistor will cause 26mV of error
voltage. By balancing the resistor values at both inverting
and non-inverting inputs, the error caused by the amplifier’s
input bias current will be reduced. The circuit in
shows how to cancel the error caused by input bias current.
. This in turn will slow down the pulse response.
F
DS100922-19
FIGURE 3. Indirectly Driving A Capacitive Load with
DC Accuracy
Figure 4
DS100922-21
FIGURE 5. Difference Application
4.2 Instrumentation Circuits
The input impendance of the previous difference amplifier is
set by the resistor R
lems of low input impendance, one way is to use a voltage
and R4. To eliminate the prob-
1,R2,R3
follower ahead of each input as shown in the following two
instrumentation amplifiers.
4.2.1 Three-op-amp Instrumentation Amplifier
The LMV721/722 can be used to build a three-op-amp instrumentation amplifier as shown in
Figure 6
DS100922-20
FIGURE 4. Cancelling the Error Caused by Input Bias
Current
4.0 Typical Single-Supply Application Circuits
4.1 Difference amplifier
The difference amplifier allows the subtraction of two voltages or, as a special case, the cancellation of a signal common to two inputs. It is useful as a computational amplifier,in
making a differential to single-ended conversion or in rejecting a common mode signal.
DS100922-30
FIGURE 6. Three-op-amp Instrumentation Amplifier
The first stage of this instrumentation amplifier is a
differential-input, differential-output amplifier, with two voltage followers. These two voltage followers assure that the
input impedance is over 100MΩ. The gain of this instrumentation amplifier is set by the ratio of R
R
and R4equal R2. Matching of R3to R1and R4to R2af-
1
fects the CMRR. For good CMRR over temperature, low drift
resistors should be used. Making R
and adding a trim pot equal to twice the difference between
R
and R4will allow the CMRR to be adjusted for optimum.
2
slightly smaller than R
4
2/R1.R3
should equal
4.2.2 Two-op-amp Instrumentation Amplifier
A two-op-amp instrumentation amplifier can also be used to
make a high-input impedance DC differential amplifier (
ure 7
). As in the two-op-amp circuit, this instrumentation am-
Fig-
plifier requires precise resistor matching for good CMRR. R
should equal to R1and R3should equal R2.
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2
4
Page 10
Application Notes (Continued)
DS100922-22
FIGURE 7. Two-op-amp Instrumentation Amplifier
4.3 Single-Supply Inverting Amplifier
There may be cases where the input signal going into the
amplifier is negative. Because the amplifier is operating in
single supply voltage, a voltage divider using R
implemented to bias the amplifier so the input signal is within
the input common-common voltage range of the amplifier.
The capacitor C
resistor R
source, V
quency, fc
As a result, the output signal is centered around mid-supply
(if the voltage divider provides V
is placed between the inverting input and
1
to block the DC signal going into the AC signal
1
. The values of R1and C1affect the cutoff fre-
IN
1
=
⁄2π R1C1.
+
/2 at the non-inverting input). The output can swing to both rails, maximizing the
signal-to-noise ratio in a low voltage system.
and R4is
3
4.4 Active Filter
4.4.1 Simple Low-Pass Active Filter
The simple low-pass filter is shown in
frequency gain (ω→o) is defined by −R
low-frequency gains other than unity to be obtained. The fil-
Figure 9
3/R1
. Its low-pass
. This allows
ter has a −20dB/decade roll-off after its corner frequency fc.
R
should be chosen equal to the parallel combination of R
2
and R3to minimize error due to bais current. The frequency
response of the filter is shown in
Figure 10
.
DS100922-24
FIGURE 9. Simple Low-Pass Active Filter
1
DS100922-23
FIGURE 8. Single-Supply Inverting Amplifier
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DS100922-25
FIGURE 10. Frequency Response of Simple Low-pass
Active Filter in
Figure 9
Note that the single-op-amp active filters are used in to the
applications that require low quality factor, Q(≤ 10), low frequency (≤ 5KHz), and low gain (≤ 10), or a small value for the
product of gain times Q(≤ 100). The op amp should have an
open loop voltage gain at the highest frequency of interest at
least 50 times larger than the gain of the filter at this frequency.In addition, the selected op amp should have a slew
rate that meets the following requirement:
Slew Rate ≥ 0.5x(ω
Where ω
the output peak-to-peak voltage.
is the highest frequency of interest, and V
H
HVOPP
)X10−6V/µsec
OPP
is
Page 11
Application Notes (Continued)
DS100922-44
FIGURE 11. A Battery Powered Microphone Preamplifier
Here is a LMV721 used as a microphone preamplifier. Since the LMV721 is a low noise and low power op amp, it makes it an
ideal candidate as a battery powered microphone preamplifier.The LMV721 is connected in an inverting configuration. Resistors,
=
=
R
R
use. The gain of the preamplifier, which is 50 (34dB), is set by resistors R
for the LMV721 is 10 MHz. This is sufficient for most audio application since the audio range is typically from 20 Hz to 20kHz. A
resistor R
amp to block out the DC voltage offset.
4.7kΩ, sets the reference half way between V
1
2
=
5kΩ is used to bias the electret microphone. Capacitors C
5
=
3V and ground. Thus, this configures the op amp for single supply
CC
=
10kΩ and R
3
=
C
1
=
2
=
500kΩ. The gain bandwidth product
4
4.7µF placed at the input and output of the op
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Page 12
Physical Dimensions inches (millimeters) unless otherwise noted
Order Number LMV721M7 or LMV721M7X
NS Package Number MAA05A
www.national.com 12
SC70-5
Page 13
Physical Dimensions inches (millimeters) unless otherwise noted (Continued)
Order Number LMV721M5 or LMV721M5X
SOT 23-5
NS Package Number MA05B
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Page 14
Physical Dimensions inches (millimeters) unless otherwise noted (Continued)
Order Number LMV722M or LMV722MX
8-Pin Small Outline
NS Package Number M08A
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Page 15
Physical Dimensions inches (millimeters) unless otherwise noted (Continued)
LMV721/LMV72210MHz, Low Noise, Low Voltage, and Low Power Operational Amplifier
Order Number LMV722MM or LMV722MMX
8-Pin MSOP
NS Package Number MUA08A
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
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.
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: support@nsc.com
www.national.com
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.
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Email: europe.support@nsc.com
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