National Semiconductor Supplier Page   LMP7731 - 2.9nV/sqrt(Hz) Low Noise, Precision, RRIO Amplifier
from the PowerWise® Family

  • Overview
  • Features & Applications
  • Diagrams
  • Specifications


National Semiconductor LMP7731The LMP7731 is a single, low noise, low offset voltage, rail-to-rail input and output, low voltage precision 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/sqrt(Hz) 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 LMP7731 has bipolar 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 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.      Datasheet

Features & Applications


Input voltage noise
          f = 3 Hz
          f = 1 kHz

3.3 nV/ √Hz
2.9 nV/ √Hz
Offset voltage (max) ±40 µV
Offset voltage drift (max ±1.0 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 per channel 2.2 mA
Supply voltage range 1.8V to 5.5V
Operating temperature range −40°C to 125°C
Input bias current ±1.5 nA

  • Thermophile amplifier
  • Gas analysis instruments
  • Photometric instrumentation
  • Medical instrumentation

    RoHS Compliant





Typical Performance & Application
Typical Performance & Application

Connection Diagram

Connection Diagram



Manufacturer Part Number Digi-Key Part Number Packaging Datasheet
LMP7731MF/NOPB LMP7731MFTR-ND Tape & Reel  
LMP7731MFCT-ND Cut Tape Datasheet
LMP7731MFDKR-ND Digi-Reel®  

PowerWise® Efficiency Specifications
Offset Voltage max, 25C 0.05 mV Voltage Noise 2.9 nV/root(Hz)
TcVos 1 uV/degC Max Input Bias Current 85 nA
CMRR 120 dB Gain Bandwidth 22 MHz
PSRR 129 dB Supply Current Per Channel 2.2 mA
Avol 130 dB PowerWise Rating 2 100 uA/MHz