Watch It!

Videos:
RMS Noise to Peak-to-Peak Noise

Spectral Noise Density to RMS Noise

Noise of a Non-inverting Operational Amplifier (Op Amp) Circuit

Noise of an Instrumentation Amp

Webinars:
Amplifier Noise Principles for the Practical Engineer

Noise Optimization in Sensor Signal Conditioning Circuits (Part I)
Part I of this online seminar covers the types, sources, characteristics, and analysis techniques of noise, and introduces a low noise design process.

Noise Optimization in Sensor Signal Conditioning Circuits (Part II)
Part II presents design dos and don'ts, as well as a number of circuit optimization techniques.

Noise Optimization in Sensor Signal Conditioning Circuits (Part III)
Part III addresses aspects of correlated and uncorrelated noise, finding the noise bandwidth of a circuit, when to balance or unbalance an amplifier input for best noise performance, noise calculation for a number of popular circuits, and much more.

Read It!

Application Note: Low Noise Amplifier Selection Guide for Optimal Noise Performance (AN-940) (pdf, 179 KB)

This application note discusses the fundamentals of both internal and external noise and identifies the tradeoffs associated in selecting the optimal amplifier for low noise design.

Tutorials:

MT-065: In-Amp Noise (pdf, 38 kB )

MT-047: Op Amp Noise (pdf, 72 kB)

MT-048: Op Amp Noise Relationships: 1/f Noise, RMS Noise, and Equivalent Noise Bandwidth (pdf, 81 kB)

MT-049: Op Amp Total Output Noise Calculations for Single-Pole System (pdf, 40 kB)

MT-050: Op Amp Total Output Noise Calculations fro Second-Order System (pdf, 38 kB)

MT-055: Chopper Stabilized (Auto-Zero) Precision Op Amps (pdf, 320 kB)

Tech Articles:
"Circuit noise analysis and optimization", Published in Planet Analog, June 2009

"Seven Steps to Successful Analog-to-Digital Signal Conversion (Noise calculation for proper signal conditioning)" (pdf)

Design It!

Circuit Note: High Speed Instrumentation Amplifier Using the AD8271 Difference Amplifier and the ADA4627-1 JFET Input Op Amp (CN-0122)

This circuit utilizes a difference amplifier and two amplifiers, which have low noise, low drift, low offset, and high speed. For high impedance sources, the ADA4627-1 is an ideal choice for the input stage amplifiers due to the extremely low input bias current of their JFET inputs.

Circuit Note: Weigh Scale Design Using the AD7781 20-Bit Sigma-Delta ADC with Internal PGA (CN0108)

This circuit is a weigh scale system that uses a pin programmable, low power, low drift 20-bit Σ-Δ converter that includes a PGA and uses an internal clock. The device simplifies the weigh scale design since most of the system building blocks are included on-chip, and is suitable for any low power or battery application.

View more Circuit Notes optimized for low noise applications (pdf, 52.8 KB)

Featured Products

High Speed (BW≥50MHz):

ADA4898-1: High voltage, low noise (1nV/√Hz), low distortion, unity gain stable, high speed op amp

AD8099: Ultra low noise (0.95nV/√Hz), low distortion, high speed op amp

AD8045: Low noise (3nV/√Hz), ultra-low distortion, voltage feedback high speed amplifier

AD8432: Dual, ultra-low noise (0.85nV/√Hz), single-ended input, differential output amplifier with 4 selectable gains

AD8331: Single VGA with ultra-low noise (0.74nV/√Hz) preamplifier and programmable R_IN

Precision (BW<50MHz):

ADA4004-1: Low noise (1.8nV/√Hz), 36V precision op amp

ADA4075-2: Low noise (2.8V/√Hz), low power precision op amp

AD8273: Low noise (26nV/√Hz RTO), very low distortion, dual channel audio difference amp

AD8275: Low noise (40nV/√Hz RTO), G=0.2, level translation, 16-bit ADC driver

AD8224: Dual-channel, JFET input, rail-to-rail instrumentation amplifier