Texas Instruments Single 8 MHz Low Power CMOS, EMI Hardened Operational Amplifier, Evaluation module LMV851EVAL/NOPB LMV851EVAL/NOPB Scheda Tecnica

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This application report presents the background, details, and usage of the EMI Rejection Ratio (EMIRR)
parameter.

1

Introduction

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2

EMI and Op Amps

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3

EMIRR Definition

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4

EMIRR Measurement

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4.1

Op Amp Configuration

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4.2

Applying the RF Signal

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4.3

Isolating the Other Pins

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4.4

Test Circuits

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5

Measurement Results for the LMV851/LMV852/LMV854

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5.1

EMIRR Vs. Frequency

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5.2

EMIRR Vs. Power

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6

Typical Applications and EMIRR

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6.1

Signal Path Application

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6.2

Cell Phone Call

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1

Offset Voltage Variation Due to a Detected RF Signal

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2

Measured Input Referred Offset Voltage Shift vs. Applied RF Peak Level

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3

Coupling the RF Signal to the IN+ Pin Circuit Diagram

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4

Coupling the RF Signal to the IN

−

Pin Circuit Diagram

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5

Coupling an RF Signal to Either of the Supply Pins Circuit Diagram

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6

Coupling an RF Signal to the Output Pin Circuit Diagram

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7

EMIRR vs. Frequency for IN+, IN

−

, V

DD

, V

SS

, and OUT

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8

EMIRR vs. RF Input Peak Level for IN+

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9

Typical Signal Path Application

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10

Pressure Sensor Application

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11

Comparing EMI Robustness

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1

SNOA497B – September 2007 – Revised April 2013

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