NSC LMP7732MA, LMP7732 Datasheet

August 2007

LMP7732

2.9 nV/sqrt(Hz) Low Noise, Precision, RRIO Amplifier

General Description

The LMP7732 is a dual low noise, low offset voltage, rail-to­rail input and output, low voltage precision amplifier. The
LMP7732 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/

with a 1/f corner of only 3 Hz and low DC offset with a
maximum value of ±40 µV, targeting high accuracy, low fre­quency applications. The LMP7732 has bipolar junction input
stages with a bias current of only 1.5 nA. This low input bias
current, complemented by the very low AC and DC levels of
voltage noise, makes the LMP7732 an excellent choice for
photometry applications.

The LMP7732 provides a wide GBW of 22 MHz while con­suming only 4 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 LMP7732 has a supply voltage range of 1.8V to 5.5V,
making it an ideal choice for battery operated portable appli­cations.

The LMP7732 is offered in an 8-pin SOIC.
The LMP7731 is the single version of this product and is of-

fered in an 5-Pin SOT23 package.

Features

(Typical values, TA = 25°C, VS = 5V)

■

Input voltage noise

—

f = 3 Hz 3.3 nV/√Hz

—

f = 1 kHz 2.9 nV/√Hz

■

Offset voltage (max) ±40 µV

■

Offset voltage drift (max) ±1.3 µV/°C

■

CMRR 130 dB

■

Open loop gain 130 dB

■

GBW 22 MHz

■

Slew rate 2.4 V/µs

■

THD @ f = 10 kHz, AV = 1, RL = 2 kΩ 0.001%

■

Supply current 4.4 mA

■

Supply voltage range 1.8V to 5.5V

■

Operating temperature range −40°C to 125°C

■

Input bias current ±1.5 nA

■

RRIO

■

8-Pin SOIC package

Applications

■

Thermopile amplifier

■

Gas analysis instruments

■

Photometric instrumentation

■

Medical instrumentation

Typical Application

Thermopile Signal Amplifier

30015001

LMP® is a registered trademark of National Semiconductor Corporation.

© 2007 National Semiconductor Corporation 300150 www.national.com

LMP7732 Low Noise, Precision, RRIO Amplifier

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
For inputs pins only 2000V
For all other pins 2000V
Machine Model 200V
Charge Device Model 1000V
VIN Differential

±2V

Supply Voltage (VS = V+ – V−)

6.0V

Storage Temperature Range −65°C to 150°C
Junction Temperature (Note 3) +150°C max
Soldering Information
Infrared or Convection (20 sec) 235°C
Wave Soldering Lead Temp. (10 sec) 260°C

Operating Ratings (Note 1)

Temperature Range −40°C to 125°C
Supply Voltage (VS = V+ – V–)

1.8V to 5.5V

Package Thermal Resistance (θJA)

8-Pin SOIC 190 °C/W

2.5V Electrical Characteristics (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 Parameter Conditions Min

(Note 6)

Typ

(Note 5)

Max

(Note 6)

Units

V

OS

Input Offset Voltage
(Note 7)

VCM = 2.0V ±9 ±50

±150

μV

VCM = 0.5V ±9 ±40

±125

TCV

OS

Input Offset Voltage Drift VCM = 2.0V ±0.5 ±1.3

μV/°C

VCM = 0.5V ±0.2 ±0.8

Input Offset Voltage Time Drift VCM = 0.5V and VCM = 2.0V 0.35

μV/month

I

B

Input Bias Current VCM = 2.0V ±1 ±30

±45

nA

VCM = 0.5V ±12 ±50

±75

I

OS

Input Offset Current VCM = 2.0V ±1 ±50

±75

nA

VCM = 0.5V ±11 ±60

±80

TCI

OS

Input Offset Current Drift VCM = 0.5V and VCM = 2.0V 0.0474 nA/°C

CMRR Common Mode Rejection Ratio

0.15V ≤ VCM ≤ 0.7V

0.23V ≤ VCM ≤ 0.7V

101

89

120

dB

1.5V ≤ VCM ≤ 2.35V

1.5V ≤ VCM ≤ 2.27V

105

99

129

PSRR Power Supply Rejection Ratio

2.5V ≤ V+ ≤ 5V

111

105

129

dB

1.8V ≤ V+ ≤ 5.5V

117

CMVR Input Common-Mode Voltage

Range

Large Signal CMRR ≥ 80 dB

0

2.5 V

A

VOL

Large Signal Voltage Gain

RL = 10 kΩ to V+/2
VO = 0.5V to 2.0V

112

104

130

dB

RL = 2 kΩ to V+/2
VO = 0.5V to 2.0V

109

90

119

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LMP7732

Symbol Parameter Conditions Min

(Note 6)

Typ

(Note 5)

Max

(Note 6)

Units

V

O

Output Swing High

RL = 10 kΩ to V+/2

4 50

75

mV

from either

rail

RL = 2 kΩ to V+/2

13 50

75

Output Swing Low

RL = 10 kΩ to V+/2

6 50

75

RL = 2 kΩ to V+/2

9 50

75

I

O

Output Short Circuit Current Sourcing, VO = V+/2

VIN (diff) = 100 mV

22

12

31

mA

Sinking, VO = V+/2
VIN (diff) = −100 mV

15

10

44

I

S

Supply Current VCM = 2.0V 4.0 5.4

6.8

mA

VCM = 0.5V 4.6 6.2

7.8

SR Slew Rate

AV = +1, CL = 10 pF, RL = 10 kΩ to V+/2
VO = 2 V

PP

2.4

V/μs

GBW Gain Bandwidth Product

CL = 20 pF, RL = 10 kΩ to V+/2

21 MHz

G

M

Gain Margin

CL = 20 pF, RL = 10 kΩ to V+/2

14 dB

Φ

M

Phase Margin

CL = 20 pF, RL = 10 kΩ to V+/2

60 deg

R

IN

Input Resistance Differential Mode 38

kΩ

Common Mode 151

MΩ

THD Total Harmonic Distortion AV = 1, fO = 1 kHz, Amplitude = 1V 0.002

%

e

n

Input-Referred Voltage Noise f = 1 kHz, VCM = 2.0V 3.0

nV/

f = 1 kHz, VCM = 0.5V 3.0

0.1 Hz to 10 Hz 75 nV

PP

i

n

Input-Referred Current Noise f = 1 kHz, VCM = 2.0V 1.1

pA/

f = 1 kHz, VCM = 0.5V 2.3

3.3V Electrical Characteristics (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 Parameter Conditions Min

(Note 6)

Typ

(Note 5)

Max

(Note 6)

Units

V

OS

Input Offset Voltage
(Note 7)

VCM = 2.5V ±6 ±50

±150

μV

VCM = 0.5V ±6 ±40

±125

TCV

OS

Input Offset Voltage Drift VCM = 2.5V ±0.5 ±1.3

μV/°C

VCM = 0.5V ±0.2 ±0.8

Input Offset Voltage Time Drift VCM = 0.5V and VCM = 2.5V 0.35

μV/month

I

B

Input Bias Current VCM = 2.5V ±1.5 ±30

±45

nA

VCM = 0.5V ±13 ±50

±77

I

OS

Input Offset Current VCM = 2.5V ±1 ±50

±70

nA

VCM = 0.5V ±11 ±60

±80

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LMP7732

Symbol Parameter Conditions Min

(Note 6)

Typ

(Note 5)

Max

(Note 6)

Units

TCI

OS

Input Offset Current Drift VCM = 0.5V and VCM = 2.5V 0.048 nA/°C

CMRR Common Mode Rejection Ratio

0.15V ≤ VCM ≤ 0.7V

0.23V ≤ VCM ≤ 0.7V

101

89

120

dB

1.5V ≤ VCM ≤ 3.15V

1.5V ≤ VCM ≤ 3.07V

105

99

130

PSRR Power Supply Rejection Ratio

2.5V ≤ V+ ≤ 5.0V

111

105

129

dB

1.8V ≤ V+ ≤ 5.5V

117

CMVR Input Common-Mode Voltage

Range

Large Signal CMRR ≥ 80 dB

0

3.3 V

A

VOL

Large Signal Voltage Gain

RL = 10 kΩ to V+/2
VO = 0.5V to 2.8V

112

104

130

dB

RL = 2 kΩ to V+/2
VO = 0.5V to 2.8V

110

92

119

V

O

Output Swing High

RL = 10 kΩ to V+/2

5 50

75

mV

from either

rail

RL = 2 kΩ to V+/2

14 50

75

Output Swing Low

RL = 10 kΩ to V+/2

9 50

75

RL = 2 kΩ to V+/2

13 50

75

I

O

Output Short Circuit Current Sourcing, VO = V+/2

VIN (diff) = 100 mV

28

22

45

mA

Sinking, VO = V+/2
VIN (diff) = −100 mV

25

20

48

I

S

Supply Current VCM = 2.5V 4.2 5.6

7.0

mA

VCM = 0.5V 4.8 6.4

8.0

SR Slew Rate

AV = +1, CL = 10 pF, RL = 10 kΩ to V+/2
VO = 2 V

PP

2.4

V/μs

GBW Gain Bandwidth Product

CL = 20 pF, RL = 10 kΩ to V+/2

22 MHz

G

M

Gain Margin

CL = 20 pF, RL = 10 kΩ to V+/2

14 dB

Φ

M

Phase Margin

CL = 20 pF, RL = 10 kΩ to V+/2

62 deg

THD Total Harmonic Distortion AV = 1, fO = 1 kHz, Amplitude = 1V 0.002

%

R

IN

Input Resistance Differential Mode 38

kΩ

Common Mode 151

MΩ

e

n

Input-Referred Voltage Noise f = 1 kHz, VCM = 2.5V

2.9
nV/

f = 1 kHz, VCM = 0.5V

2.9

0.1 Hz to 10 Hz 75 nV

PP

i

n

Input-Referred Current Noise f = 1 kHz, VCM = 2.5V 1.1

pA/

f = 1 kHz, VCM = 0.5V 2.1

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LMP7732

5V Electrical Characteristics (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 Parameter Conditions Min

(Note 6)

Typ

(Note 5)

Max

(Note 6)

Units

V

OS

Input Offset Voltage
(Note 7)

VCM = 4.5V ±6 ±50

±150

μV

VCM = 0.5V ±6 ±40

±125

TCV

OS

Input Offset Voltage Drift VCM = 4.5V ±0.5 ±1.3

μV/°C

VCM = 0.5V ±0.2 ±0.8

Input Offset Voltage Time Drift VCM = 0.5V and VCM = 4.5V 0.35

μV/month

I

B

Input Bias Current VCM = 4.5V ±1.5 ±30

±50

nA

VCM = 0.5V ±14 ±50

±85

I

OS

Input Offset Current VCM = 4.5V ±1 ±50

±70

nA

VCM = 0.5V ±11 ±65

±80

TCI

OS

Input Offset Current Drift VCM = 0.5V and VCM = 4.5V 0.0482 nA/°C

CMRR Common Mode Rejection Ratio

0.15V ≤ VCM ≤ 0.7V

0.23V ≤ VCM ≤ 0.7V

101

89

120

dB

1.5V ≤ VCM ≤ 4.85V

1.5V ≤ VCM ≤ 4.77V

105

99

130

PSRR Power Supply Rejection Ratio

2.5V ≤ V+ ≤ 5V

111

105

129

dB

1.8V ≤ V+ ≤ 5.5V

117

CMVR Input Common-Mode Voltage

Range

Large Signal CMRR ≥ 80 dB

0

5 V

A

VOL

Large Signal Voltage Gain

RL = 10 kΩ to V+/2
VO = 0.5V to 4.5V

112

104

130

dB

RL = 2 kΩ to V+/2
VO = 0.5V to 4.5V

110

94

119

V

O

Output Swing High

RL = 10 kΩ to V+/2

8 50

75

mV

from either

rail

RL = 2 kΩ to V+/2

24 50

75

Output Swing Low

RL = 10 kΩ to V+/2

9 50

75

RL = 2 kΩ to V+/2

23 50

75

I

O

Output Short Circuit Current Sourcing, VO = V+/2

VIN (diff) = 100 mV

33

27

47

mA

Sinking, VO = V+/2
VIN (diff) = −100 mV

30

25

49

I

S

Supply Current VCM = 4.5V 4.4 6.0

7.4

mA

VCM = 0.5V 5.0 6.8

8.4

SR Slew Rate

AV = +1, CL = 10 pF, RL = 10 kΩ to V+/2
VO = 2 V

PP

2.4

V/μs

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LMP7732

Symbol Parameter Conditions Min

(Note 6)

Typ

(Note 5)

Max

(Note 6)

Units

GBW Gain Bandwidth Product

CL = 20 pF, RL = 10 kΩ to V+/2

22 MHz

G

M

Gain Margin

CL = 20 pF, RL = 10 kΩ to V+/2

12 dB

Φ

M

Phase Margin

CL = 20 pF, RL = 10 kΩ to V+/2

65 deg

R

IN

Input Resistance Differential Mode 38

kΩ

Common Mode 151

MΩ

THD Total Harmonic Distortion AV = 1, fO = 1 kHz, Amplitude = 1V 0.001

%

e

n

Input-Referred Voltage Noise f = 1 kHz, VCM = 4.5V

2.9
nV/

f = 1 kHz, VCM = 0.5V

2.9

0.1 Hz to 10 Hz 75 nV

PP

i

n

Input-Referred Current Noise f = 1 kHz, VCM = 4.5V

1.1
pA/

f = 1 kHz, VCM = 0.5V

2.2

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) Field­Induced Charge-Device Model, applicable std. JESD22-C101-C (ESD FICDM std. of JEDEC).

Note 3: The maximum power dissipation is a function of T

J(MAX)

, θJA, and TA. The maximum allowable power dissipation at any ambient temperature is

PD = (T

J(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 Diagram

8-Pin SOIC

30015003

Top View

Ordering Information

Package Part Number Package Marking Transport Media NSC Drawing

8-Pin SOIC

LMP7732MA

LMP7732MA

95 units/Rails

M08A

LMP7732MAX 2.5k Units Tape and Reel

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LMP7732