NSC LMP7731MAX

LMP7731
2.9 nV/sqrt(Hz) Low Noise, Precision, RRIO Amplifier
General Description
Features
The LMP7731 is a single, low noise, rail-to-rail input and output, low voltage amplifier. The LMP7731 is part of the LMP®
precision amplifier family and is ideal for precision and low
noise applications with low voltage requirements.
This operational amplifier offers low voltage noise of 2.9 nV/
√Hz with a 1/f corner of only 3 Hz. The LMP7731 has bipolar
input stages with a bias current of only 1.5 nA. This low input
bias current, complemented by the very low level of voltage
noise, makes the LMP7731 an excellent choice for photometry applications.
The LMP7731 provides a wide GBW of 22 MHz while consuming only 2 mA of current. This high gain bandwidth along
with the high open loop gain of 130 dB enables accurate signal conditioning in applications with high closed loop gain
requirements.
The LMP7731 has a supply voltage range of 1.8V to 5.5V,
making it an ideal choice for battery operated portable applications.
The LMP7731 is offered in the space saving 5-Pin SOT-23
and 8-Pin SOIC packages.
(Typical values, TA = 25°C, VS = 5V)
■ Input voltage noise
— f = 3 Hz
— f = 1 kHz
■ CMRR
■ Open loop gain
■ GBW
■ Slew rate
■ THD @ f = 10 kHz, AV = +1, RL = 2 kΩ
■ Supply current per channel
■ Supply voltage range
■ Operating temperature range
■ Input bias current
■ RRIO
3.3 nV/√Hz
2.9 nV/√Hz
130 dB
130 dB
22 MHz
2.4 V/µs
0.001%
2.2 mA
1.8V to 5.5V
−40°C to 125°C
±1.5 nA
Applications
■ Gas analysis instruments
■ Photometric instrumentation
■ Medical instrumentation
Typical Performance Characteristics
Input Voltage Noise vs. Frequency
Input Current Noise vs. Frequency
20175261
20175262
LMP® is a registered trademark of National Semiconductor Corporation.
© 2009 National Semiconductor Corporation
201752
www.national.com
LMP7731 2.9 nV/sqrt(Hz) Low Noise, Precision, RRIO Amplifier
May 20, 2009
LMP7731
Storage Temperature Range
Junction Temperature (Note 3)
Soldering Information
Infrared or Convection (20 sec)
Wave Soldering Lead Temp. (10 sec)
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
Inputs pins only
All other pins
Machine Model
Charge Device Model
VIN Differential
Supply Voltage (VS = V+ – V−)
Operating Ratings
2000V
2000V
200V
1000V
±2V
6.0V
2.5V Electrical Characteristics
−65°C to 150°C
+150°C max
235°C
260°C
(Note 1)
Temperature Range
Supply Voltage (VS = V+ – V–)
−40°C to 125°C
1.8V to 5.5V
Package Thermal Resistance (θJA)
5-Pin SOT-23
8-Pin SOIC
265°C/W
190°C/W
(Note 4)
Unless otherwise specified, all limits are guaranteed for TA = 25°C, V+ = 2.5V, V− = 0V, VCM = V+/2, RL >10 kΩ to V+/2. Boldface limits apply at the temperature extremes.
Symbol
VOS
TCVOS
IB
IOS
TCIOS
Parameter
Input Offset Voltage
(Note 7)
Input Offset Voltage Temperature Drift
Conditions
VCM = 2.0V
±9
±500
±600
VCM = 0.5V
±9
±500
±600
VCM = 2.0V
±0.5
±5.5
VCM = 0.5V
±0.2
±5.5
VCM = 2.0V
±1
±30
±45
VCM = 0.5V
±12
±50
±75
VCM = 2.0V
±1
±50
±75
VCM = 0.5V
±11
±60
±80
Input Bias Current
Input Offset Current
Input Offset Current Drift
VCM = 0.5V and VCM = 2.0V
0.15V ≤ VCM ≤ 0.7V
CMRR
Common Mode Rejection Ratio
Power Supply Rejection Ratio
0.0474
101
89
120
1.5V ≤ VCM ≤ 2.35V
105
99
129
2.5V ≤ V+ ≤ 5V
111
105
129
0.23V ≤ VCM ≤ 0.7V
1.5V ≤ VCM ≤ 2.27V
PSRR
Min
Typ
Max
(Note 6) (Note 5) (Note 6)
1.8V ≤ V+ ≤ 5.5V
CMVR
Common Mode Voltage Range
Large Signal CMRR ≥ 80 dB
AVOL
Open Loop Voltage Gain
www.national.com
μV/°C
nA
nA
nA/°C
dB
dB
0
2.5
RL = 10 kΩ to
VOUT = 0.5V to 2.0V
130
RL = 2 kΩ to V+/2
VOUT = 0.5V to 2.0V
109
90
119
2
μV
117
112
104
V+/2
Units
V
dB
Parameter
Conditions
Min
Typ
Max
(Note 6) (Note 5) (Note 6)
RL = 10 kΩ to V+/2
4
50
75
RL = 2 kΩ to V+/2
13
50
75
RL = 10 kΩ to V+/2
6
50
75
RL = 2 kΩ to V+/2
9
50
75
Output Voltage Swing High
VOUT
Output Voltage Swing Low
IOUT
Output Current
IS
Supply Current
(Per Channel)
Sourcing, VOUT = V+/2
VIN (diff) = 100 mV
22
12
31
Sinking, VOUT = V+/2
VIN (diff) = −100 mV
15
10
44
VCM = 2.0V
VCM = 0.5V
Units
mV from
either rail
mA
2.0
2.7
3.4
2.3
3.1
3.9
mA
SR
Slew Rate
AV = +1, CL = 10 pF, RL = 10 kΩ to V+/2,
VO = 2 VPP
2.4
V/μs
GBW
Gain Bandwidth
CL = 20 pF, RL = 10 kΩ to V+/2
21
MHz
GM
Gain Margin
CL = 20 pF, RL = 10 kΩ to V+/2
14
dB
ΦM
Phase Margin
CL = 20 pF, RL = 10 kΩ to V+/2
60
deg
RIN
Input Resistance
THD+N
Total Harmonic Distortion + Noise
Input Referred Voltage Noise Density
en
Input Voltage Noise
in
Input Referred Current Noise Density
Differential Mode
38
kΩ
Common Mode
151
MΩ
0.002
%
AV = 1, f = 1 kHz, Amplitude = 1V
f = 1 kHz, VCM = 2.0V
3
f = 1 kHz, VCM = 0.5V
3
0.1 Hz to 10 Hz
75
f = 1 kHz, VCM = 2.0V
1.1
f = 1 kHz, VCM = 0.5V
2.3
3.3V Electrical Characteristics
nV/
nVPP
pA/
(Note 4)
Unless otherwise specified, all limits are guaranteed for TA = 25°C, V+ = 3.3V, V− = 0V, VCM = V+/2, RL > 10 kΩ to V+/2. Boldface limits apply at the temperature extremes.
Symbol
VOS
TCVOS
IB
IOS
Parameter
Input Offset Voltage
(Note 7)
Input Offset Voltage Temperature Drift
Conditions
Min
Typ
Max
(Note 6) (Note 5) (Note 6)
VCM = 2.5V
±6
±500
±600
VCM = 0.5V
±6
±500
±600
VCM = 2.5V
±0.5
±5.5
VCM = 0.5V
±0.2
±5.5
VCM = 2.5V
±1.5
±30
±45
VCM = 0.5V
±13
±50
±77
VCM = 2.5V
±1
±50
±70
±11
±60
±80
Input Bias Current
Input Offset Current
VCM = 0.5V
3
Units
μV
μV/°C
nA
nA
www.national.com
LMP7731
Symbol
LMP7731
Symbol
TCIOS
CMRR
Parameter
Input Offset Current Drift
Common Mode Rejection Ratio
Conditions
Power Supply Rejection Ratio
Units
0.048
nA/°C
VCM = 0.5V and VCM = 2.5V
0.15V ≤ VCM ≤ 0.7V
101
89
120
1.5V ≤ VCM ≤ 3.15V
105
99
130
2.5V ≤ V+ ≤ 5.0V
111
105
129
0.23V ≤ VCM ≤ 0.7V
1.5V ≤ VCM ≤ 3.07V
PSRR
Min
Typ
Max
(Note 6) (Note 5) (Note 6)
1.8V ≤ V+ ≤ 5.5V
CMVR
Common Mode Voltage Range
Open Loop Voltage Gain
dB
117
Large Signal CMRR ≥ 80 dB
0
3.3
RL = 10 kΩ to
VOUT = 0.5V to 2.8V
112
104
130
RL = 2 kΩ to V+/2
VOUT = 0.5V to 2.8V
110
92
119
V+/2
AVOL
5
50
75
RL = 2 kΩ to V+/2
14
50
75
RL = 10 kΩ to V+/2
9
50
75
RL = 2 kΩ to V+/2
13
50
75
VOUT
Output Voltage Swing Low
Output Current
IS
Supply Current
(Per Channel)
Sourcing, VOUT = V+/2
VIN (diff) = 100 mV
28
22
45
Sinking, VOUT = V+/2
VIN (diff) = -100 mV
25
20
48
V
dB
RL = 10 kΩ to V+/2
Output Voltage Swing High
IOUT
dB
mV from
either rail
mA
VCM = 2.5V
2.1
2.8
3.5
VCM = 0.5V
2.4
3.2
4.0
mA
SR
Slew Rate
AV = +1, CL = 10 pF, RL = 10 kΩ to V+/2,
VOUT = 2 VPP
2.4
V/μs
GBW
Gain Bandwidth
CL = 20 pF, RL = 10 kΩ to V+/2
22
MHz
GM
Gain Margin
CL = 20 pF, RL = 10 kΩ to V+/2
14
dB
ΦM
Phase Margin
V+/2
62
deg
38
kΩ
151
MΩ
0.002
%
RIN
Input Resistance
THD+N
Total Harmonic Distortion + Noise
en
Input Referred Voltage Noise Density
Input Voltage Noise
in
Input Referred Current Noise Density
www.national.com
CL = 20 pF, RL = 10 kΩ to
Differential Mode
Common Mode
AV = 1, f = 1 kHz, Amplitude = 1V,
f = 1 kHz, VCM = 2.5V
2.9
f = 1 kHz, VCM = 0.5V
2.9
0.1 Hz to 10 Hz
65
f = 1 kHz, VCM = 2.5V
1.1
f = 1 kHz, VCM = 0.5V
2.1
4
nV/
nVPP
pA/
(Note 4)
Unless otherwise specified, all limits are guaranteed for TA = 25°C, V+ = 5V, V− = 0V, VCM = V+/2, RL > 10 kΩ to V+/2. Boldface
limits apply at the temperature extremes.
Symbol
VOS
TCVOS
IB
IOS
TCIOS
Parameter
Input Offset Voltage
(Note 7)
Input Offset Voltage Temperature Drift
Conditions
VCM = 4.5V
±6
±500
±600
VCM = 0.5V
±6
±500
±600
VCM = 4.5V
±0.5
±5.5
VCM = 0.5V
±0.2
±5.5
VCM = 4.5V
±1.5
±30
±50
VCM = 0.5V
±14
±50
±85
VCM = 4.5V
±1
±50
±70
VCM = 0.5V
±11
±65
±80
Input Bias Current
Input Offset Current
Input Offset Current Drift
VCM = 0.5V and VCM = 4.5V
0.15V ≤ VCM ≤ 0.7V
CMRR
Common Mode Rejection Ratio
Power Supply Rejection Ratio
0.0482
101
89
120
1.5V ≤ VCM ≤ 4.85V
105
99
130
2.5V ≤ V+ ≤ 5V
111
105
129
0.23V ≤ VCM ≤ 0.7V
1.5V ≤ VCM ≤ 4.77V
PSRR
Min
Typ
Max
(Note 6) (Note 5) (Note 6)
1.8V ≤ V+ ≤ 5.5V
CMVR
Common Mode Voltage Range
Large Signal CMRR ≥ 80 dB
AVOL
Open Loop Voltage Gain
0
112
104
130
RL = 2 kΩ to V+/2
VOUT = 0.5V to 4.5V
110
94
119
IS
V
dB
8
50
75
RL = 2 kΩ to V+/2
24
50
75
RL = 10 kΩ to V+/2
9
50
75
RL = 2 kΩ to V+/2
23
50
75
Sourcing, VOUT = V+/2
VIN (diff) = 100 mV
33
27
47
Sinking, VOUT = V+/2
VIN (diff) = -100 mV
30
25
49
mV from
either rail
mA
2.2
3.0
3.7
VCM = 0.5V
2.5
3.4
4.2
VCM = 4.5V
nA
dB
RL = 10 kΩ to V+/2
Output Voltage Swing Low
Supply Current
(Per Channel)
nA
nA/°C
5
VOUT
Output Current
μV/°C
dB
Output Voltage Swing High
IOUT
μV
117
RL = 10 kΩ to
VOUT = 0.5V to 4.5V
V+/2
Units
mA
SR
Slew Rate
AV = +1, CL = 10 pF, RL = 10 kΩ to V+/2,
VOUT = 2 VPP
2.4
V/μs
GBW
Gain Bandwidth
CL = 20 pF, RL = 10 kΩ to V+/2
22
MHz
5
www.national.com
LMP7731
5V Electrical Characteristics
LMP7731
Symbol
Parameter
Min
Typ
Max
(Note 6) (Note 5) (Note 6)
Conditions
Units
GM
Gain Margin
CL = 20 pF, RL = 10 kΩ to V+/2
12
dB
ΦM
Phase Margin
CL = 20 pF, RL = 10 kΩ to V+/2
65
deg
RIN
Input Resistance
Differential Mode
38
kΩ
151
MΩ
THD+N
Total Harmonic Distortion + Noise
0.001
%
en
Common Mode
AV = 1, f = 1 kHz, Amplitude = 1V
Input Referred Voltage Noise Density
Input Voltage Noise
in
Input Referred Current Noise Density
f = 1 kHz, VCM = 4.5V
2.9
f = 1 kHz, VCM = 0.5V
2.9
0.1 Hz to 10 Hz
78
f = 1 kHz, VCM = 4.5V
1.1
f = 1 kHz, VCM = 0.5V
2.2
nV/
nVPP
pA/
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
Tables.
Note 2: Human Body Model, applicable std. MIL-STD-883, Method 3015.7. Machine Model, applicable std. JESD22-A115-A (ESD MM std. of JEDEC)
Field-Induced Charge-Device Model, applicable std. JESD22-C101-C (ESD FICDM std. of JEDEC).
Note 3: The maximum power dissipation is a function of TJ(MAX), θJA. The maximum allowable power dissipation at any ambient temperature is
PD = (TJ(MAX) – TA)/ θJA. All numbers apply for packages soldered directly onto a PC Board.
Note 4: 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 TJ = TA. No guarantee of parametric performance is indicated in the electrical tables under conditions of internal self-heating where TJ >
TA. Absolute maximum Ratings indicate junction temperature limits beyond which the device maybe permanently degraded, either mechanically or electrically.
Note 5: Typical values represent the most likely parametric norm as determined at the time of characterization. Actual typical values may vary over time and will
also depend on the application and configuration. The typical values are not tested and are not guaranteed on shipped production material.
Note 6: All limits are guaranteed by testing, statistical analysis or design.
Note 7: Ambient production test is performed at 25°C with a variance of ±3°C.
Connection Diagrams
5-Pin SOT-23
8-Pin SOIC
20175202
Top View
20175203
Top View
Ordering Information
Package
Part Number
Package Marking
LMP7731MF
5-Pin SOT-23
LMP7731MFE
AY3A
250 Units Tape an Reel
LMP7731MFX
8-Pin SOIC
www.national.com
LMP7731MA
LMP7731MAX
Transport Media
NSC Drawing
1k Units Tape and Reel
MF05A
3k Units Tape and Reel
95 Units/Rail
LMP7731MA
2.5k Tape and Reel
6
M08A
Unless otherwise noted: TA = 25°C, RL > 10 kΩ, VCM = VS/2.
Offset Voltage Distribution
TCVOS Distribution
20175238
20175234
Offset Voltage Distribution
TCVOS Distribution
20175236
20175239
Offset Voltage Distribution
TCVOS Distribution
20175240
20175235
7
www.national.com
LMP7731
Typical Performance Characteristics
LMP7731
Offset Voltage Distribution
TCVOS Distribution
20175241
20175237
Offset Voltage vs. Temperature
Offset Voltage vs. Temperature
20175251
20175252
PSRR vs. Frequency
CMRR vs. Frequency
20175256
20175229
www.national.com
8
LMP7731
Offset Voltage vs. Supply Voltage
Offset Voltage vs. VCM
20175242
20175243
Offset Voltage vs. VCM
Offset Voltage vs. VCM
20175245
20175244
Input Offset Voltage Time Drift
Slew Rate vs. Supply Voltage
20175220
20175230
9
www.national.com
LMP7731
Time Domain Voltage Noise
Time Domain Voltage Noise
20175267
20175269
Time Domain Voltage Noise
Output Voltage vs. Output Current
20175268
20175259
Input Bias Current vs. VCM
Input Bias Current vs. VCM
20175226
20175225
www.national.com
10
Open Loop Frequency Response Over Temperature
20175218
20175227
Open Loop Frequency Response
Open Loop Frequency Response
20175228
20175219
THD+N vs. Frequency
THD+N vs. Output Voltage
20175257
20175258
11
www.national.com
LMP7731
Input Bias Current vs. VCM
LMP7731
Large Signal Step Response
Small Signal Step Response
20175222
20175221
Large Signal Step Response
Small Signal Step Response
20175224
20175223
Supply Current vs. Supply Voltage
Output Swing High vs. Supply Voltage
20175246
www.national.com
20175250
12
LMP7731
Output Swing Low vs. Supply Voltage
Sinking Current vs, Supply Voltage
20175249
20175247
Sourcing Current vs. Supply Voltage
20175248
13
www.national.com
LMP7731
Figure 1 shows that as the common mode voltage gets closer
to one of the extreme ends, current I1 significantly increases.
This increased current shows as an increase in voltage drop
across resistor R1 equal to I1*R1 on IN+ of the amplifier. This
voltage contributes to the offset voltage of the amplifier. When
common mode voltage is in the mid-range, the transistors are
operating in the linear region and I1 is significantly small. The
voltage drop due to I1 across R1 can be ignored as it is orders
of magnitude smaller than the amplifier's input offset voltage.
As the common mode voltage gets closer to one of the rails,
the offset voltage generated due to I1 increases and becomes
comparable to the amplifiers offset voltage.
Application Information
LMP7731
The LMP7731 is a single, low noise, rail-to-rail input and output, and low voltage amplifier.
The low input voltage noise of only 2.9 nV/√Hz with a 1/f corner at 3 Hz makes the LMP7731 ideal for sensor applications
where DC accuracy is of importance.
The LMP7731 has a high gain bandwidth of 22 MHz. This
wide bandwidth enables use of the amplifier at higher gain
settings while retaining usable bandwidth for the application.
This is particularly beneficial when system designers need to
use sensors with very limited output voltage range as it allows
larger gains in one stage which in turn increases the signal to
noise ratio.
The LMP7731 has proprietary input bias cancellation circuitry
on the input stages. This allows the LMP7731 to have only
about 1.5 nA bias current with a bipolar input stage. This low
input bias current, paired with the inherent lower input voltage
noise of bipolar input stages makes the LMP7731 an excellent
choice for precision applications. The combination of low input bias current, and low input voltage noise enables the user
to achieve unprecedented accuracy and higher signal integrity.
National Semiconductor is heavily committed to precision
amplifiers and the market segment they serve. Technical support and extensive characterization data are available for
sensitive applications or applications with a constrained error
budget.
The LMP7731 is offered in the space saving 5-Pin SOT-23
and 8-Pin SOIC packages. These small packages are ideal
solutions for area constrained PC boards and portable electronics.
20175206
FIGURE 1. Input Bias Current Cancellation
INPUT BIAS CURRENT CANCELLATION
The LMP7731 has proprietary input bias current cancellation
circuitry on their input stages.
The LMP7731 has rail-to-rail input. This is achieved by having
two input stages in parallel. Figure 1 shows only one of the
input stages as the circuitry is symmetrical for both stages.
INPUT VOLTAGE NOISE MEASUREMENT
The LMP7731 has very low input voltage noise. The peak-topeak input voltage noise of the LMP7731 can be measured
using the test circuit shown in Figure 2
20175255
FIGURE 2. 0.1 Hz to 10 Hz Noise Test Circuit
The frequency response of this noise test circuit at the 0.1 Hz
corner is defined by only one zero. The test time for the 0.1
Hz to 10 Hz noise measurement using this configuration
should not exceed 10 seconds, as this time limit acts as an
www.national.com
additional zero to reduce or eliminate the noise contributions
of noise from frequencies below 0.1 Hz.
Figure 3 shows typical peak-to-peak noise for the LMP7731
measured with the circuit in Figure 2 for the LMP7731.
14
DIODES BETWEEN THE INPUTS
The LMP7731 has a set of anti-parallel diodes between the
input pins as shown in Figure 5. These diodes are present to
protect the input stage of the amplifier. At the same time, they
limit the amount of differential input voltage that is allowed on
the input pins. A differential signal larger than the voltage
needed to turn on the diodes might cause damage to the
diodes. The differential voltage between the input pins should
be limited to ±3 diode drops or the input current needs to be
limited to ±20 mA.
20175268
FIGURE 3. 0.1 Hz to 10 Hz Input Voltage Noise
Measuring the very low peak-to-peak noise performance of
the LMP7731, requires special testing attention. In order to
achieve accurate results, the device should be warmed up for
at least five minutes. This is so that the input offset voltage of
the op amp settles to a value. During this warm up period, the
offset can typically change by a few µV because the chip
temperature increases by about 30°C. If the 10 seconds of
the measurement is selected to include this warm up time,
some of this temperature change might show up as the measured noise. Figure 4 shows the start-up drift of five typical
LMP7731 units.
20175204
FIGURE 5. Anti-Parallel Diodes between Inputs
20175230
FIGURE 4. Start-Up Input Offset Voltage Drift
15
www.national.com
LMP7731
During the peak-to-peak noise measurement, the LMP7731
must be shielded. This prevents offset variations due to airflow. Offset can vary by a few nV due to this airflow and that
can invalidate measurements of input voltage noise with a
magnitude which is in the same range. For similar reasons,
sudden motions must also be restricted in the vicinity of the
test area. The feed-through which results from this motion
could increase the observed noise value which in turn would
invalidate the measurement.
LMP7731
DRIVING AN ADC
Analog to Digital Converters, ADCs, usually have a sampling
capacitor on their input. When the ADC's input is directly connected to the output of the amplifier a charging current flows
from the amplifier to the ADC. This charging current causes
a momentary glitch that can take some time to settle. There
are different ways to minimize this effect. One way is to slow
down the sampling rate. This method gives the amplifier sufficient time to stabilize its output. Another way to minimize the
glitch caused by the switch capacitor is to have an external
capacitor connected to the input of the ADC. This capacitor is
chosen so that its value is much larger than the internal
switching capacitor and it will hence provide the voltage needed to quickly and smoothly charge the ADC's sampling capacitor. Since this large capacitor will be loading the output of
the amplifier as well, an isolation resistor is needed between
the output of the amplifier and this capacitor. The isolation
resistor, RISO, separates the additional load capacitance from
the output of the amplifier and will also form a low-pass filter
and can be designed to provide noise reduction as well as
anti-aliasing. The drawback to having RISO is that it reduces
signal swing since there is some voltage drop across it.
Figure 6 (a) shows the ADC directly connected to the amplifier. To minimize the glitch in this setting, a slower sample rate
needs to be used. Figure 6 (b) shows RISO and an external
capacitor used to minimize the glitch.
www.national.com
20175205
FIGURE 6. Driving an ADC
16
LMP7731
Physical Dimensions inches (millimeters) unless otherwise noted
5-Pin SOT-23
NS Package Number MF05A
8-Pin SOIC
NS Package Number M08A
17
www.national.com
LMP7731 2.9 nV/sqrt(Hz) Low Noise, Precision, RRIO Amplifier
Notes
For more National Semiconductor product information and proven design tools, visit the following Web sites at:
Products
Design Support
Amplifiers
www.national.com/amplifiers
WEBENCH® Tools
www.national.com/webench
Audio
www.national.com/audio
App Notes
www.national.com/appnotes
Clock and Timing
www.national.com/timing
Reference Designs
www.national.com/refdesigns
Data Converters
www.national.com/adc
Samples
www.national.com/samples
Interface
www.national.com/interface
Eval Boards
www.national.com/evalboards
LVDS
www.national.com/lvds
Packaging
www.national.com/packaging
Power Management
www.national.com/power
Green Compliance
www.national.com/quality/green
Switching Regulators
www.national.com/switchers
Distributors
www.national.com/contacts
LDOs
www.national.com/ldo
Quality and Reliability
www.national.com/quality
LED Lighting
www.national.com/led
Feedback/Support
www.national.com/feedback
Voltage Reference
www.national.com/vref
Design Made Easy
www.national.com/easy
www.national.com/powerwise
Solutions
www.national.com/solutions
Mil/Aero
www.national.com/milaero
PowerWise® Solutions
Serial Digital Interface (SDI) www.national.com/sdi
Temperature Sensors
www.national.com/tempsensors SolarMagic™
www.national.com/solarmagic
Wireless (PLL/VCO)
www.national.com/wireless
www.national.com/training
PowerWise® Design
University
THE CONTENTS OF THIS DOCUMENT ARE PROVIDED IN CONNECTION WITH NATIONAL SEMICONDUCTOR CORPORATION
(“NATIONAL”) PRODUCTS. NATIONAL MAKES NO REPRESENTATIONS OR WARRANTIES WITH RESPECT TO THE ACCURACY
OR COMPLETENESS OF THE CONTENTS OF THIS PUBLICATION AND RESERVES THE RIGHT TO MAKE CHANGES TO
SPECIFICATIONS AND PRODUCT DESCRIPTIONS AT ANY TIME WITHOUT NOTICE. NO LICENSE, WHETHER EXPRESS,
IMPLIED, ARISING BY ESTOPPEL OR OTHERWISE, TO ANY INTELLECTUAL PROPERTY RIGHTS IS GRANTED BY THIS
DOCUMENT.
TESTING AND OTHER QUALITY CONTROLS ARE USED TO THE EXTENT NATIONAL DEEMS NECESSARY TO SUPPORT
NATIONAL’S PRODUCT WARRANTY. EXCEPT WHERE MANDATED BY GOVERNMENT REQUIREMENTS, TESTING OF ALL
PARAMETERS OF EACH PRODUCT IS NOT NECESSARILY PERFORMED. NATIONAL ASSUMES NO LIABILITY FOR
APPLICATIONS ASSISTANCE OR BUYER PRODUCT DESIGN. BUYERS ARE RESPONSIBLE FOR THEIR PRODUCTS AND
APPLICATIONS USING NATIONAL COMPONENTS. PRIOR TO USING OR DISTRIBUTING ANY PRODUCTS THAT INCLUDE
NATIONAL COMPONENTS, BUYERS SHOULD PROVIDE ADEQUATE DESIGN, TESTING AND OPERATING SAFEGUARDS.
EXCEPT AS PROVIDED IN NATIONAL’S TERMS AND CONDITIONS OF SALE FOR SUCH PRODUCTS, NATIONAL ASSUMES NO
LIABILITY WHATSOEVER, AND NATIONAL DISCLAIMS ANY EXPRESS OR IMPLIED WARRANTY RELATING TO THE SALE
AND/OR USE OF NATIONAL PRODUCTS INCLUDING LIABILITY OR WARRANTIES RELATING TO FITNESS FOR A PARTICULAR
PURPOSE, MERCHANTABILITY, OR INFRINGEMENT OF ANY PATENT, COPYRIGHT OR OTHER INTELLECTUAL PROPERTY
RIGHT.
LIFE SUPPORT POLICY
NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR
SYSTEMS WITHOUT THE EXPRESS PRIOR WRITTEN APPROVAL OF THE CHIEF EXECUTIVE OFFICER AND GENERAL
COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein:
Life support devices or systems are devices 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. A critical component is any component in 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 and the National Semiconductor logo are registered trademarks of National Semiconductor Corporation. All other
brand or product names may be trademarks or registered trademarks of their respective holders.
Copyright© 2009 National Semiconductor Corporation
For the most current product information visit us at www.national.com
National Semiconductor
Americas Technical
Support Center
Email: [email protected]
Tel: 1-800-272-9959
www.national.com
National Semiconductor Europe
Technical Support Center
Email: [email protected]
National Semiconductor Asia
Pacific Technical Support Center
Email: [email protected]
National Semiconductor Japan
Technical Support Center
Email: [email protected]