Datasheet

ManualsBrandsTEXAS INSTRUMENTS ManualsLinear ICsLinear IC - Op-amp Multi-purpose SOIC 8

0.1

1 10 1k 10k

FREQUENCY (Hz)

100

VOLTAGE NOISE (nV/

Hz)

= 2.5V, 3.3V, 5V

= 0.5V

= 2.5V

0.1

1 10 1k 10k

FREQUENCY (Hz)

100

CURRENT NOISE (pA/

Hz)

= 2.5V, 3.3V, 5V

= 0.5V

= 2.5V

LMP7731

www.ti.com

SNOSAT6E –JULY 2007–REVISED MARCH 2013

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

Check for Samples: LMP7731

FEATURES

DESCRIPTION

The LMP7731 is a single, low noise, rail-to-rail input

(Typical Values, T

= 25°C, V

= 5V)

and output, low voltage amplifier. The LMP7731 is

• Input Voltage Noise

part of the LMP™ precision amplifier family and is

– f = 3 Hz 3.3 nV/√Hz

ideal for precision and low noise applications with low

voltage requirements.

– f = 1 kHz 2.9 nV/√Hz

• CMRR 130 dB

This operational amplifier offers low voltage noise of

2.9 nV/√Hz with a 1/f corner of only 3 Hz. The

• Open Loop Gain 130 dB

LMP7731 has bipolar input stages with a bias current

• GBW 22 MHz

of only 1.5 nA. This low input bias current,

• Slew Rate 2.4 V/µs

complemented by the very low level of voltage noise,

makes the LMP7731 an excellent choice for

• THD @ f = 10 kHz, A

= +1, R

= 2 kΩ 0.001%

photometry applications.

• Supply Current per Channel 2.2 mA

The LMP7731 provides a wide GBW of 22 MHz while

• Supply Voltage Range 1.8V to 5.5V

consuming only 2 mA of current. This high gain

• Operating Temperature Range −40°C to 125°C

bandwidth along with the high open loop gain of 130

• Input Bias Current ±1.5 nA

dB enables accurate signal conditioning in

applications with high closed loop gain requirements.

• RRIO

The LMP7731 has a supply voltage range of 1.8V to

APPLICATIONS

5.5V, making it an ideal choice for battery operated

portable applications.

• Gas Analysis Instruments

The LMP7731 is offered in the space saving 5-Pin

• Photometric Instrumentation

SOT-23 and 8-Pin SOIC packages.

• Medical Instrumentation

Typical Performance Characteristics

Input Voltage Noise Input Current Noise

vs. vs.

Frequency Frequency

Figure 1. Figure 2.

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas

Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

2LMP is a trademark of Texas Instruments.

3All other trademarks are the property of their respective owners.

PRODUCTION DATA information is current as of publication date.

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.

Summary of content (26 pages)

PAGE 1
LMP7731 www.ti.com SNOSAT6E – JULY 2007 – REVISED MARCH 2013 2.9 nV/sqrt(Hz) Low Noise, Precision, RRIO Amplifier Check for Samples: LMP7731 FEATURES DESCRIPTION 1 (Typical Values, TA = 25°C, VS = 5V) 23 • • • • • • • • • • • Input Voltage Noise – f = 3 Hz 3.3 nV/√Hz – f = 1 kHz 2.9 nV/√Hz 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 per Channel 2.2 mA Supply Voltage Range 1.8V to 5.
PAGE 2
LMP7731 SNOSAT6E – JULY 2007 – REVISED MARCH 2013 www.ti.com These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam during storage or handling to prevent electrostatic damage to the MOS gates. Absolute Maximum Ratings ESD Tolerance (3) (1) (2) Human Body Model Inputs pins only 2000V All other pins 2000V Machine Model 200V Charge Device Model 1000V VIN Differential ±2V Supply Voltage (VS = V+ – V−) 6.
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LMP7731 www.ti.com SNOSAT6E – JULY 2007 – REVISED MARCH 2013 2.5V Electrical Characteristics (1) (continued) Unless otherwise specified, all limits are ensured 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. Parameter IOS TCIOS CMRR PSRR Test Conditions Min (2) AVOL (3) Common Mode Rejection Ratio Power Supply Rejection Ratio Common Mode Voltage Range Open Loop Voltage Gain ±1 VCM = 0.5V ±11 ±60 ±80 VCM = 0.
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LMP7731 SNOSAT6E – JULY 2007 – REVISED MARCH 2013 3.3V Electrical Characteristics www.ti.com (1) Unless otherwise specified, all limits are ensured 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. Parameter Input Offset Voltage VOS Test Conditions Min (2) Typ (3) IB Input Offset Voltage Temperature Drift VCM = 2.5V ±6 VCM = 0.5V ±6 ±500 ±600 VCM = 2.5V ±0.5 ±5.5 VCM = 0.5V ±0.2 ±5.5 VCM = 2.5V ±1.
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LMP7731 www.ti.com SNOSAT6E – JULY 2007 – REVISED MARCH 2013 3.3V Electrical Characteristics (1) (continued) Unless otherwise specified, all limits are ensured 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.
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LMP7731 SNOSAT6E – JULY 2007 – REVISED MARCH 2013 www.ti.com 5V Electrical Characteristics (1) (continued) Unless otherwise specified, all limits are ensured for TA = 25°C, V+ = 5V, V− = 0V, VCM = V+/2, RL > 10 kΩ to V+/2. Boldface limits apply at the temperature extremes.
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LMP7731 www.ti.com SNOSAT6E – JULY 2007 – REVISED MARCH 2013 Typical Performance Characteristics Unless otherwise noted: TA = 25°C, RL > 10 kΩ, VCM = VS/2. Offset Voltage Distribution TCVOS Distribution 10 16 VS = 2.5V VS = 2.5V VCM = 2V 14 VCM = 2V 12 -40°C d TA d 25°C PERCENTAGE (%) PERCENTAGE (%) 8 6 4 10 8 6 4 2 2 0 -50 -40 -30 -20 -10 0 0 -0.5 10 20 30 40 50 0 VOS (PV) 0.5 Figure 5. 1.5 Figure 6. Offset Voltage Distribution TCVOS Distribution 10 16 VS = 3.
PAGE 8
LMP7731 SNOSAT6E – JULY 2007 – REVISED MARCH 2013 www.ti.com Typical Performance Characteristics (continued) Unless otherwise noted: TA = 25°C, RL > 10 kΩ, VCM = VS/2. Offset Voltage Distribution TCVOS Distribution 14 25 VS = 5V VS = 3.3V, 5V 12 VCM = 0.5V 20 PERCENTAGE (%) PERCENTAGE (%) 10 8 6 4 VCM = 0.5V -40°C d TA d 125°C 15 10 5 2 0 -40 -30 -20 -10 0 10 20 30 0 -1.5 40 -1 -0.5 TCVOS (PV/°C) Figure 11. Figure 12. Offset Voltage vs. Temperature 0.5 Offset Voltage vs.
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LMP7731 www.ti.com SNOSAT6E – JULY 2007 – REVISED MARCH 2013 Typical Performance Characteristics (continued) Unless otherwise noted: TA = 25°C, RL > 10 kΩ, VCM = VS/2. Offset Voltage vs. Supply Voltage Offset Voltage vs. VCM 5 100 VS = 2.5V 50 -5 VOS (PV) OFFSET VOLTAGE (PV) 75 25°C 0 -40°C -10 125°C 25 85°C 25°C 0 -15 -40°C -25 85°C -20 -50 -25 1.5 125°C 2 2.5 3 3.5 4 4.5 5 -75 5.5 0 0.5 1 SUPPLY VOLTAGE (V) Figure 18. Offset Voltage vs. VCM Offset Voltage vs.
PAGE 10
LMP7731 SNOSAT6E – JULY 2007 – REVISED MARCH 2013 www.ti.com Typical Performance Characteristics (continued) Unless otherwise noted: TA = 25°C, RL > 10 kΩ, VCM = VS/2. Time Domain Voltage Noise Time Domain Voltage Noise Figure 23. Figure 24. Time Domain Voltage Noise Output Voltage vs. Output Current 1000 VS = 2.5V, 3.3V, 5V VOUT FROM RAIL (mV) 800 VS = 2.5V 600 400 SINK 200 0 -200 -400 SOURCE -600 -800 0 5 10 15 20 25 30 OUTPUT CURRENT (mA) Figure 25. Figure 26.
PAGE 11
LMP7731 www.ti.com SNOSAT6E – JULY 2007 – REVISED MARCH 2013 Typical Performance Characteristics (continued) Unless otherwise noted: TA = 25°C, RL > 10 kΩ, VCM = VS/2. Input Bias Current vs. VCM Open Loop Frequency Response Over Temperature 100 100 INPUT BIAS CURRENT (nA) 225 VS = 5V 125°C 80 GAIN 80 180 60 40 60 20 GAIN (dB) 25°C 0 -20 -40 PHASE 20 45 VS = 2.5V, TA = 25°C -40°C 0 0 VS = 2.5V, 3.3V, 5V -20 RL = 10 k: TA = -40°C, 25°C, 85°C, 125°C -40 1M 10M 100k 1k 10k -80 0 0.
PAGE 12
LMP7731 SNOSAT6E – JULY 2007 – REVISED MARCH 2013 www.ti.com Typical Performance Characteristics (continued) Unless otherwise noted: TA = 25°C, RL > 10 kΩ, VCM = VS/2. Small Signal Step Response 20 mV/DIV 500 mV/DIV Large Signal Step Response VS = 5V VIN = 2 VPP f = 10 kHz VS = 5V VIN = 100 mVPP f = 10 kHz AV = +1 AV = +1 RL = 10 k: RL = 10 k: CL = 10 pF CL = 10 pF Figure 35. Figure 36.
PAGE 13
LMP7731 www.ti.com SNOSAT6E – JULY 2007 – REVISED MARCH 2013 Typical Performance Characteristics (continued) Unless otherwise noted: TA = 25°C, RL > 10 kΩ, VCM = VS/2. Output Swing Low vs. Supply Voltage Sinking Current vs, Supply Voltage 60 40 -40°C RL = 2 k: 25°C 50 125°C 30 25 ISINK (mA) VOUT FROM RAIL (mV) 35 85°C 20 15 85°C 40 125°C 30 -40°C 25°C 10 20 5 0 1.5 2 2.5 3 3.5 4 4.5 5 10 1.5 5.5 2 2.5 3 3.5 4 4.5 SUPPLY VOLTAGE (V) SUPPLY VOLTAGE (V) Figure 41.
PAGE 14
LMP7731 SNOSAT6E – JULY 2007 – REVISED MARCH 2013 www.ti.com 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.
PAGE 15
LMP7731 www.ti.com SNOSAT6E – JULY 2007 – REVISED MARCH 2013 INPUT VOLTAGE NOISE MEASUREMENT The LMP7731 has very low input voltage noise. The peak-to-peak input voltage noise of the LMP7731 can be measured using the test circuit shown in Figure 45 0.1 PF 100 k: 10: 2 k: LMP7731 + + LMP7731 VOLTAGE GAIN = 50,000 4.7 PF - 4.3 k: 22 PF 2.2 PF 110 k: 100 k: SCOPE x1 RIN = 1M 24.3 k: 0.1 PF Figure 45. 0.
PAGE 16
LMP7731 SNOSAT6E – JULY 2007 – REVISED MARCH 2013 www.ti.com OFFSET VOLTAGE DRIFT (PV) 1 VS = 5V 0.8 RL = 2 k: 0.6 0.4 0.2 0 50 0 100 150 200 250 300 TIME (s) Figure 47. Start-Up Input Offset Voltage Drift 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.
PAGE 17
LMP7731 www.ti.com SNOSAT6E – JULY 2007 – REVISED MARCH 2013 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.
PAGE 18
LMP7731 SNOSAT6E – JULY 2007 – REVISED MARCH 2013 www.ti.com REVISION HISTORY Changes from Revision D (March 2013) to Revision E • 18 Page Changed layout of National Data Sheet to TI format ..........................................................................................................
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PACKAGE OPTION ADDENDUM www.ti.
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PACKAGE OPTION ADDENDUM www.ti.com 11-Apr-2013 In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis.
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PACKAGE MATERIALS INFORMATION www.ti.com 8-Apr-2013 TAPE AND REEL INFORMATION *All dimensions are nominal Device Package Package Pins Type Drawing SPQ Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) B0 (mm) K0 (mm) P1 (mm) W Pin1 (mm) Quadrant LMP7731MAX/NOPB SOIC D 8 2500 330.0 12.4 6.5 5.4 2.0 8.0 12.0 Q1 LMP7731MF/NOPB SOT-23 DBV 5 1000 178.0 8.4 3.2 3.2 1.4 4.0 8.0 Q3 LMP7731MFE/NOPB SOT-23 DBV 5 250 178.0 8.4 3.2 3.2 1.4 4.0 8.
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PACKAGE MATERIALS INFORMATION www.ti.com 8-Apr-2013 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) LMP7731MAX/NOPB SOIC D 8 2500 367.0 367.0 35.0 LMP7731MF/NOPB SOT-23 DBV 5 1000 210.0 185.0 35.0 LMP7731MFE/NOPB SOT-23 DBV 5 250 210.0 185.0 35.0 LMP7731MFX/NOPB SOT-23 DBV 5 3000 210.0 185.0 35.
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