National Semiconductor LMP7732 Technical data

June 16, 2008

LMP7732

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

LMP7732 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 the 8-Pin SOIC and MSOP pack­ages.

The LMP7731 is the single version of this product and is of­fered in the 5-Pin SOT-23 and 8-Pin SOIC packages.

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

■

Applications

Thermopile amplifier

■

Gas analysis instruments

■

Photometric instrumentation

■

Medical instrumentation

■

Typical Application

LMP® is a registered trademark of National Semiconductor Corporation.

Thermopile Signal Amplifier

30015001

© 2008 National Semiconductor Corporation 300150 www.national.com

Absolute Maximum Ratings (Note 1)

If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/

LMP7732

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

Supply Voltage (VS = V+ – V−)

±2V

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–)

Package Thermal Resistance (θJA)

8-Pin SOIC 190 °C/W
8-Pin MSOP 235°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)

V

OS

Input Offset Voltage

VCM = 2.0V ±9 ±50

(Note 7)

VCM = 0.5V ±9 ±40

TCV

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

OS

VCM = 0.5V ±0.2 ±0.8

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

I

B

Input Bias Current VCM = 2.0V ±1 ±30

VCM = 0.5V ±12 ±50

I

OS

Input Offset Current VCM = 2.0V ±1 ±50

VCM = 0.5V ±11 ±60

TCI

CMRR Common Mode Rejection Ratio

PSRR Power Supply Rejection Ratio

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

OS

0.15V ≤ VCM ≤ 0.7V

0.23V ≤ VCM ≤ 0.7V

1.5V ≤ VCM ≤ 2.35V

1.5V ≤ VCM ≤ 2.27V

2.5V ≤ V+ ≤ 5V

101

89

105

99

111

105

117

0

112

104

109

90

CMVR Common Mode Voltage Range

A

VOL

Open Loop Voltage Gain

1.8V ≤ V+ ≤ 5.5V
Large Signal CMRR ≥ 80 dB

RL = 10 kΩ to V+/2
V

= 0.5V to 2.0V

OUT

RL = 2 kΩ to V+/2
V

= 0.5V to 2.0V

OUT

Typ

(Note 5)

120

129

129

130

119

1.8V to 5.5V

Max

(Note 6)

±150

±125

±45

±75

±75

±80

2.5 V

Units

μV

μV/°C

μV/month

nA

nA

dB

dB

dB

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LMP7732

Symbol Parameter Conditions Min

(Note 6)

V

OUT

Output Voltage Swing High

RL = 10 kΩ to V+/2

RL = 2 kΩ to V+/2

Output Voltage Swing Low

RL = 10 kΩ to V+/2

RL = 2 kΩ to V+/2

I

OUT

I

S

Output Current Sourcing, V

VIN (diff) = 100 mV

Sinking, V
VIN (diff) = −100 mV

OUT

OUT

= V+/2

= V+/2

22

12

15

10

Supply Current VCM = 2.0V 4.0 5.4

4 50

13 50

6 50

9 50

Typ

(Note 5)

31

44

Max

(Note 6)

VCM = 0.5V 4.6 6.2

SR Slew Rate

GBW Gain Bandwidth

G

M

Φ

M

R

IN

Gain Margin

Phase Margin

Input Resistance Differential Mode 38

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

= 2 V

OUT

PP

CL = 20 pF, RL = 10 kΩ to V+/2

CL = 20 pF, RL = 10 kΩ to V+/2

CL = 20 pF, RL = 10 kΩ to V+/2

2.4

21 MHz

14 dB

60 deg

Common Mode 151

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

e

n

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

f = 1 kHz, VCM = 0.5V 3.0

Input Voltage Noise 0.1 Hz to 10 Hz 75 nV

i

n

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

f = 1 kHz, VCM = 0.5V 2.3

75

75

75

75

6.8

7.8

Units

mV from

either rail

mA

mA

V/μs

kΩ

MΩ

%

nV/

PP

pA/

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)

V

OS

Input Offset Voltage

VCM = 2.5V ±6 ±50

(Note 7)

VCM = 0.5V ±6 ±40

TCV

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

OS

VCM = 0.5V ±0.2 ±0.8

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

I

B

Input Bias Current VCM = 2.5V ±1.5 ±30

VCM = 0.5V ±13 ±50

I

OS

Input Offset Current VCM = 2.5V ±1 ±50

VCM = 0.5V ±11 ±60

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Typ

(Note 5)

Max

(Note 6)

±150

±125

±45

±77

±70

±80

Units

μV

μV/°C

μV/month

nA

nA

Symbol Parameter Conditions Min

TCI

LMP7732

CMRR Common Mode Rejection Ratio

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

OS

0.15V ≤ VCM ≤ 0.7V

0.23V ≤ VCM ≤ 0.7V

1.5V ≤ VCM ≤ 3.15V

1.5V ≤ VCM ≤ 3.07V

PSRR Power Supply Rejection Ratio

2.5V ≤ V+ ≤ 5.0V

(Note 6)

101

89

105

99

111

Typ

(Note 5)

120

130

129

105

117

0

112

130

104

110

119

92

5 50

14 50

9 50

13 50

28

45

22

25

48

20

CMVR Common Mode Voltage Range

A

VOL

V

OUT

Open Loop Voltage Gain

Output Voltage Swing High

Output Voltage Swing Low

I

OUT

I

S

Output Current Sourcing, V

Supply Current VCM = 2.5V 4.2 5.6

1.8V ≤ V+ ≤ 5.5V
Large Signal CMRR ≥ 80 dB

RL = 10 kΩ to V+/2
V

= 0.5V to 2.8V

OUT

RL = 2 kΩ to V+/2
V

= 0.5V to 2.8V

OUT

RL = 10 kΩ to V+/2

RL = 2 kΩ to V+/2

RL = 10 kΩ to V+/2

RL = 2 kΩ to V+/2

= V+/2

OUT

VIN (diff) = 100 mV

Sinking, V

OUT

= V+/2

VIN (diff) = −100 mV

VCM = 0.5V 4.8 6.4

SR Slew Rate

GBW Gain Bandwidth

G

M

Φ

M

Gain Margin

Phase Margin

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

= 2 V

OUT

PP

CL = 20 pF, RL = 10 kΩ to V+/2

CL = 20 pF, RL = 10 kΩ to V+/2

CL = 20 pF, RL = 10 kΩ to V+/2

2.4

22 MHz

14 dB

62 deg

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

R

IN

Input Resistance Differential Mode 38

Common Mode 151

e

n

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

f = 1 kHz, VCM = 0.5V

2.9

2.9

Input Voltage Noise 0.1 Hz to 10 Hz 75 nV

i

n

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

f = 1 kHz, VCM = 0.5V 2.1

Max

(Note 6)

3.3 V

75

75

75

75

7.0

8.0

Units

dB

dB

dB

mV from

either rail

mA

mA

V/μs

%

kΩ

MΩ

nV/

PP

pA/

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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)

V

OS

Input Offset Voltage

VCM = 4.5V ±6 ±50

(Note 7)

VCM = 0.5V ±6 ±40

TCV

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

OS

VCM = 0.5V ±0.2 ±0.8

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

I

B

Input Bias Current VCM = 4.5V ±1.5 ±30

VCM = 0.5V ±14 ±50

I

OS

Input Offset Current VCM = 4.5V ±1 ±50

VCM = 0.5V ±11 ±65

TCI

CMRR Common Mode Rejection Ratio

PSRR Power Supply Rejection Ratio

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

OS

0.15V ≤ VCM ≤ 0.7V

0.23V ≤ VCM ≤ 0.7V

1.5V ≤ VCM ≤ 4.85V

1.5V ≤ VCM ≤ 4.77V

2.5V ≤ V+ ≤ 5V

101

89

105

99

111

105

117

0

112

104

110

94

8 50

24 50

9 50

23 50

33

27

30

25

CMVR Common Mode Voltage Range

A

VOL

V

OUT

Open Loop Voltage Gain

Output Voltage Swing High

Output Voltage Swing Low

I

OUT

I

S

Output Current Sourcing, V

Supply Current VCM = 4.5V 4.4 6.0

1.8V ≤ V+ ≤ 5.5V
Large Signal CMRR ≥ 80 dB

RL = 10 kΩ to V+/2
V

= 0.5V to 4.5V

OUT

RL = 2 kΩ to V+/2
V

= 0.5V to 4.5V

OUT

RL = 10 kΩ to V+/2

RL = 2 kΩ to V+/2

RL = 10 kΩ to V+/2

RL = 2 kΩ to V+/2

= V+/2

OUT

VIN (diff) = 100 mV

Sinking, V

OUT

= V+/2

VIN (diff) = −100 mV

VCM = 0.5V 5.0 6.8

SR Slew Rate

GBW Gain Bandwidth

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

= 2 V

OUT

PP

CL = 20 pF, RL = 10 kΩ to V+/2

22 MHz

Typ

(Note 5)

120

130

129

130

119

47

49

2.4

Max

(Note 6)

±150

±125

μV/month

±50

±85

±70

±80

5 V

75

75

75

75

7.4

8.4

LMP7732

Units

μV

μV/°C

nA

nA

dB

dB

dB

mV from

either rail

mA

mA

V/μs

5 www.national.com

Symbol Parameter Conditions Min

G

M

LMP7732

Φ

M

R

IN

Gain Margin

Phase Margin

CL = 20 pF, RL = 10 kΩ to V+/2

CL = 20 pF, RL = 10 kΩ to V+/2

Input Resistance Differential Mode 38

(Note 6)

12 dB

65 deg

Typ

(Note 5)

Max

(Note 6)

Common Mode 151

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

e

n

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

f = 1 kHz, VCM = 0.5V

2.9

2.9

Input Voltage Noise 0.1 Hz to 10 Hz 75 nV

i

n

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

f = 1 kHz, VCM = 0.5V

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
PD = (T

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.

- TA)/ θJA. All numbers apply for packages soldered directly onto a PC board.

J(MAX)

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

J(MAX)

1.1

2.2

Units

kΩ

MΩ

%

nV/

PP

pA/

Connection Diagram

8-Pin SOIC/MSOP

Top View

30015003

Ordering Information

Package Part Number Package Marking Transport Media NSC Drawing

8-Pin SOIC

8-Pin MSOP

LMP7732MA

LMP7732MAX 2.5k Units Tape and Reel

LMP7732MA

LMP7732MM

AZ3A

LMP7732MMX 3.5k Units Tape and Reel

95 units/Rails

1k Units Tape and Reel

M08A

MUA08ALMP7732MME 250 Units Tape and Reel

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