February 11, 2008
LME49723
Dual High Fidelity Audio Operational Amplifier
General Description
The LME49723 is part of the ultra-low distortion, low noise,
high slew rate operational amplifier series optimized and fully
specified for high performance, high fidelity applications.
Combining advanced leading-edge process technology with
state-of-the-art circuit design, the LME49723 audio opera-
tional amplifiers deliver superior audio signal amplification for
outstanding audio performance. The LME49723 combines
extremely low voltage noise density (3.6nV/√Hz) with van-
ishingly low THD+N (0.0002%) to easily satisfy the most
demanding audio applications. To ensure that the most chal-
lenging loads are driven without compromise, the LME49723
has a high slew rate of ±20V/μs and an output current capa-
bility of ±26mA. Further, dynamic range is maximized by an
output stage that drives 2kΩ loads to within 1V of either power
supply voltage and to within 1.4V when driving 600Ω loads.
The LME49723's outstanding CMRR (100dB), PSRR
(100dB), and VOS (0.3mV) give the amplifier excellent oper-
ational amplifier DC performance.
The LME49723 has a wide supply range of ±2.5V to ±17V.
Over this supply range the LME49723’s input circuitry main-
tains excellent common-mode and power supply rejection, as
well as maintaining its low input bias current. The LME49723
is unity gain stable.
The LME49723 is available in an 8–lead narrow body SOIC.
Demonstration boards are available for each package.
Key Specifications
■ Power Supply Voltage Range ±2.5V to ±17V
■
THD+N (AV = 1, VOUT = 3VRMS, fIN = 1kHz)
RL = 2kΩ0.0002% (typ)
RL = 600Ω 0.0002% (typ)
■ Input Noise Density 3.6nV/√Hz (typ)
■ Slew Rate ±8V/μs (typ)
■ Gain Bandwidth Product 17MHz (typ)
■ Open Loop Gain (RL = 600Ω) 105dB (typ)
■ Input Bias Current 200nA (typ)
■ Input Offset Voltage 0.3mV (typ)
Features
■Easily drives 600Ω loads
■Optimized for superior audio signal fidelity
■Output short circuit protection
■PSRR and CMRR exceed 100dB (typ)
■SOIC package
Applications
■High quality audio amplification
■High fidelity preamplifiers
■High fidelity multimedia
■Phono pre amps
■High performance professional audio
■High fidelity equalization and crossover networks
■High performance line drivers
■High performance line receivers
■High fidelity active filters
Typical Application
300362k5
Passively Equalized RIAA Phono Preamplifier
© 2008 National Semiconductor Corporation 300362 www.national.com
LME49723 Dual High Fidelity Audio Operational Amplifier
Connection Diagram
30036255
Order Number LME49723MA
See NS Package Number — M08A
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LME49723
Absolute Maximum Ratings (Notes 1, 2)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Power Supply Voltage
(VS = V+ - V-)36V
Storage Temperature −65°C to 150°C
Input Voltage (V-) - 0.7V to (V+) + 0.7V
Output Short Circuit (Note 3) Continuous
Power Dissipation Internally Limited
ESD Susceptibility (Note 4) 800V
ESD Susceptibility (Note 5) 180V
Junction Temperature 150°C
Thermal Resistance
θJA (SO) 145°C/W
Temperature Range
TMIN ≤ TA ≤ TMAX –40°C ≤ TA ≤ 85°C
Supply Voltage Range ±2.5V ≤ VS ≤ ± 17V
Electrical Characteristics for the LME49723 (Notes 1, 2) The specifications apply for VS = ±15V,
RL = 2kΩ, fIN = 1kHz, TA = 25°C, unless otherwise specified.
Symbol Parameter Conditions
LME49723 Units
(Limits)
Typical Limit
(Note 6) (Note 7)
THD+N Total Harmonic Distortion + Noise
AV = 1, VOUT = 3Vrms
RL = 2kΩ
RL = 600Ω
0.0002
0.0002 0.0004
% (max)
IMD Intermodulation Distortion AV = 1, VOUT = 3VRMS
Two-tone, 60Hz & 7kHz 4:1 0.0005 %
GBWP Gain Bandwidth Product 19 15 MHz (min)
SR Slew Rate ±8 ±6 V/μs (min)
FPBW Full Power Bandwidth
VOUT = 1VP-P, –3dB
referenced to output magnitude
at f = 1kHz
4
MHz
en
Equivalent Input Noise Voltage fBW = 20Hz to 20kHz 0.45 0.65 μVRMS
(max)
Equivalent Input Noise Density f = 1kHz
f = 10Hz
3.2
8.5
5 nV/√Hz
(max)
inCurrent Noise Density f = 1kHz
f = 10Hz
0.7
1.3
pA/√Hz
VOS Offset Voltage ±0.3 1 mV (max)
ΔVOS/ΔTemp Average Input Offset Voltage Drift vs
Temperature –40°C ≤ TA ≤ 85°C 0.2 μV/°C
PSRR Average Input Offset Voltage Shift vs
Power Supply Voltage ΔVS = 20V (Note 8) 100 95 dB (min)
ISOCH-CH Channel-to-Channel Isolation fIN = 1kHz
fIN = 20kHz
118
112
dB
IBInput Bias Current VCM = 0V 200 300 nA (max)
ΔIOS/ΔTemp Input Bias Current Drift vs
Temperature –40°C ≤ TA ≤ 85°C 0.1 nA/°C
IOS Input Offset Current VCM = 0V 7 100 nA (max)
VIN-CM Common-Mode Input Voltage Range ±14 (V+) – 2.0
(V-) + 2.0 V (min)
CMRR Common-Mode Rejection –10V<Vcm<10V 100 90 dB (min)
ZIN
Differential Input Impedance 30 kΩ
Common Mode Input Impedance –10V<Vcm<10V 1000 MΩ
AVOL Open Loop Voltage Gain
–10V<Vout<10V, RL = 600Ω 100 98
dB (min)
–10V<Vout<10V, RL = 2kΩ105
–10V<Vout<10V, RL = 10kΩ105
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LME49723
Symbol Parameter Conditions
LME49723 Units
(Limits)
Typical Limit
(Note 6) (Note 7)
VOUTMAX Maximum Output Voltage Swing
RL = 600Ω ±13.5 ±12.5
V (min)
RL = 2kΩ±14.0
RL = 10kΩ±14.1
IOUT Output Current RL = 600Ω, VS = ±17V ±25 ±21 mA (min)
IOUT-CC Instantaneous Short Circuit Current +53
–42
mA
ROUT Output Impedance
fIN = 10kHz
Closed-Loop
Open-Loop
0.01
13
Ω
CLOAD Capacitive Load Drive Overshoot 100pF 16 %
ISTotal Quiescent Current IOUT = 0mA 6.7 7.5 mA (max)
Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur.
Note 2: Operating Ratings indicate conditions for which the device is functional, but do not guarantee specific performance limits. For guaranteed specifications
and test conditions, see the Electrical Characteristics. The guaranteed specifications apply only for the test conditions listed. Some performance characteristics
may degrade when the device is not operated under the listed test conditions.
Note 3: Amplifier output connected to GND, any number of amplifiers within a package.
Note 4: Human body model, 100pF discharged through a 1.5kΩ resistor.
Note 5: Machine Model ESD test is covered by specification EIAJ IC-121-1981. A 200pF cap is charged to the specified voltage and then discharged directly into
the IC with no external series resistor (resistance of discharge path must be under 50Ω).
Note 6: Typical specifications are specified at +25ºC and represent the most likely parametric norm.
Note 7: Tested limits are guaranteed to National's AOQL (Average Outgoing Quality Level).
Note 8: PSRR is measured as follows: VOS is measured at two supply voltages, ±5V and ±15V. PSRR = | 20log(ΔVOS/ΔVS) |.
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LME49723
Typical Performance Characteristics
THD+N vs Output Voltage
VS = ±5V, RL = 2kΩ
30036281
THD+N vs Output Voltage
VS = ±5V, RL = 10kΩ
30036282
THD+N vs Output Voltage
VS = ±5V, RL = 600Ω
30036283
THD+N vs Output Voltage
VS = ±15V, RL = 2kΩ
30036284
THD+N vs Output Voltage
VS = ±15V, RL = 10kΩ
30036285
THD+N vs Output Voltage
VS = ±15V, RL = 600Ω
30036286
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LME49723
THD+N vs Frequency
VS = ±15V, VOUT = 3VRMS, RL = 2kΩ
30036287
THD+N vs Frequency
VS = ±15V, VOUT = 3VRMS, RL = 10kΩ
30036288
THD+N vs Frequency
VS = ±15V, VOUT = 3VRMS, RL = 600Ω
30036289
PSRR+ vs Frequency
VS = ±15V, RL = 2kΩ, VRIPPLE = 200mVPP
30036272
PSRR+ vs Frequency
VS = ±5V, RL = 10kΩ, VRIPPLE = 200mVPP
30036273
PSRR+ vs Frequency
VS = ±5V, RL = 600Ω, VRIPPLE = 200mVPP
30036274
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LME49723
PSRR+ vs Frequency
VS = ±15V, RL = 2kΩ, VRIPPLE = 200mVPP
30036275
PSRR+ vs Frequency
VS = ±15V, RL = 10kΩ, VRIPPLE = 200mVPP
30036276
PSRR+ vs Frequency
VS = ±15V, RL = 600Ω, VRIPPLE = 200mVPP
30036277
PSRR- vs Frequency
VS = ±5V, RL = 2kΩ, VRIPPLE = 200mVPP
30036266
PSRR- vs Frequency
VS = ±5V, RL = 10kΩ, VRIPPLE = 200mVPP
30036267
PSRR- vs Frequency
VS = ±5V, RL = 600Ω, VRIPPLE = 200mVPP
30036268
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LME49723
PSRR- vs Frequency
VS = ±15V, RL = 2kΩ, VRIPPLE = 200mVPP
30036269
PSRR- vs Frequency
VS = ±15V, RL = 10kΩ, VRIPPLE = 200mVPP
30036270
PSRR- vs Frequency
VS = ±15V, RL = 10kΩ, VRIPPLE = 200mVPP
30036271
CMRR vs Frequency
VS = ±15V, RL = 2kΩ, VIN = 200mVPP
300362r4
CMRR vs Frequency
VS = ±15V, RL = 10kΩ, VIN = 200mVPP
30036256
CMRR vs Frequency
VS = ±15V, RL = 600Ω, VIN = 200mVPP
30036257
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LME49723
Crosstalk vs Frequency
VS = ±15V, VOUT = 3VRMS, RL = 2kΩ,
30036258
Crosstalk vs Frequency
VS = ±15V, VOUT = 3VRMS, RL = 10kΩ,
30036259
Crosstalk vs Frequency
VS = ±15V, VOUT = 3VRMS, RL = 600Ω,
30036260
IMD vs Output Voltage
VS = ±5V, RL = 2kΩ,
30036290
IMD vs Output Voltage
VS = ±5V, RL = 10kΩ,
30036291
IMD vs Output Voltage
VS = ±5V, RL = 600Ω,
30036292
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LME49723
Output Voltage vs Load Resistance
VS = ±5V, THD+N = 1%
30036261
Output Voltage vs Load Resistance
VDD = 15V, VSS = –15V, THD+N = 0.1%
30036262
Output Voltage vs Supply Voltage
RL = 2kΩ, THD+N = 0.1%
30036263
Output Voltage vs Supply Voltage
RL = 10kΩ, THD+N = 0.1%
30036264
Output Voltage vs Supply Voltage
RL = 600Ω, THD+N = 1%
30036265
Supply Current vs Supply Voltage
RL = 2kΩ
30036278
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LME49723
Supply Current vs Supply Voltage
RL = 10kΩ
30036279
Supply Current vs Supply Voltage
RL = 600Ω
30036280
Noninverting Amp
30036224
Noninverting Amp
30036225
Inverting Amp
30036226
Voltage Gain & Phase vs Frequency
30036210
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LME49723
Power Bandwidth
30036215
Equivalent Input Noise vs Frequency
30036204
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LME49723
Application Information
DISTORTION MEASUREMENTS
The vanishingly low residual distortion produced by
LME49723 is below the capabilities of all commercially avail-
able equipment. This makes distortion measurements just
slightly more difficult than simply connecting a distortion me-
ter to the amplifier’s inputs and outputs. The solution, how-
ever, is quite simple: an additional resistor. Adding this
resistor extends the resolution of the distortion measurement
equipment.
The LME49723’s low residual distortion is an input referred
internal error. As shown in Figure 1, adding the 10Ω resistor
connected between the amplifier’s inverting and non-inverting
inputs changes the amplifier’s noise gain. The result is that
the error signal (distortion) is amplified by a factor of 101. Al-
though the amplifier’s closed-loop gain is unaltered, the feed-
back available to correct distortion errors is reduced by 101,
which means that measurement resolution increases by 101.
To ensure minimum effects on distortion measurements,
keep the value of R1 low as shown in Figure 1.
This technique is verified by duplicating the measurements
with high closed loop gain and/or making the measurements
at high frequencies. Doing so produces distortion compo-
nents that are within the measurement equipment’s capabili-
ties. This datasheet’s THD+N and IMD values were generat-
ed using the above described circuit connected to an Audio
Precision System Two Cascade.
300362k4
FIGURE 1. THD+N and IMD Distortion Test Circuit
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LME49723
The LME49723 is a high speed op amp with excellent phase
margin and stability. Capacitive loads up to 100pF will cause
little change in the phase characteristics of the amplifiers and
are therefore allowable.
Capacitive loads greater than 100pF must be isolated from
the output. The most straightforward way to do this is to put
a resistor in series with the output. This resistor will also pre-
vent excess power dissipation if the output is accidentally
shorted.
30036227
Complete shielding is required to prevent induced pick up from external sources. Always check with oscilloscope for power line noise.
Noise Measurement Circuit
Total Gain: 115 dB @f = 1 kHz
Input Referred Noise Voltage: en = V0/560,000 (V)
RIAA Preamp Voltage Gain, RIAA
Deviation vs Frequency
30036228
Flat Amp Voltage Gain vs
Frequency
30036229
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LME49723
TYPICAL APPLICATIONS
Balanced to Single Ended Converter
30036232
VO = V1–V2
Adder/Subtracter
30036233
VO = V1 + V2 − V3 − V4
Sine Wave Oscillator
30036234
Second Order High Pass Filter
(Butterworth)
30036235
Illustration is f0 = 1 kHz
Second Order Low Pass Filter
(Butterworth)
30036236
Illustration is f0 = 1 kHz
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LME49723
State Variable Filter
30036237
Illustration is f0 = 1 kHz, Q = 10, ABP = 1
AC/DC Converter
30036238
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LME49723
2 Channel Panning Circuit (Pan Pot)
30036239
Line Driver
30036240
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LME49723
Tone Control
30036241
Illustration is:
fL = 32 Hz, fLB = 320 Hz
fH =11 kHz, fHB = 1.1 kHz
30036242
RIAA Preamp
30036203
Av = 35 dB
En = 0.33 μV
S/N = 90 dB
f = 1 kHz
A Weighted
A Weighted, VIN = 10 mV
@f = 1 kHz
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LME49723
Balanced Input Mic Amp
30036243
Illustration is:
V0 = 101(V2 − V1)
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LME49723
10 Band Graphic Equalizer
30036244
fo (Hz) C1C2R1R2
32 0.12μF4.7μF 75kΩ 500Ω
64 0.056μF3.3μF 68kΩ 510Ω
125 0.033μF1.5μF 62kΩ 510Ω
250 0.015μF0.82μF 68kΩ 470Ω
500 8200pF 0.39μF 62kΩ 470Ω
1k 3900pF 0.22μF 68kΩ 470Ω
2k 2000pF 0.1μF 68kΩ 470Ω
4k 1100pF 0.056μF 62kΩ 470Ω
8k 510pF 0.022μF 68kΩ 510Ω
16k 330pF 0.012μF 51kΩ 510Ω
Note 9: At volume of change = ±12 dB
Q = 1.7
Reference: “AUDIO/RADIO HANDBOOK”, National Semiconductor, 1980, Page 2–61
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LME49723
Revision History
Rev Date Description
1.0 01/07/08 Initial release.
1.01 02/11/08 Text edits.
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LME49723
Physical Dimensions inches (millimeters) unless otherwise noted
Narrow SOIC Package
Order Number LME49723MA
NS Package Number M08A
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LME49723
Notes
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LME49723
Notes
LME49723 Dual High Fidelity Audio Operational Amplifier
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