SBOS855E January   2017  – December 2022 OPA1677 , OPA1678 , OPA1679

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information: OPA1677
    5. 6.5 Thermal Information: OPA1678
    6. 6.6 Thermal Information: OPA1679
    7. 6.7 Electrical Characteristics
    8. 6.8 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Phase Reversal Protection
      2. 7.3.2 Electrical Overstress
      3. 7.3.3 EMI Rejection Ratio (EMIRR)
        1. 7.3.3.1 EMIRR IN+ Test Configuration
    4. 7.4 Device Functional Modes
      1. 7.4.1 Operating Voltage
  8. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Capacitive Loads
    2. 8.2 Typical Applications
      1. 8.2.1 Phantom-Powered Preamplifier for Piezo Contact Microphones
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1 Power Supply
          2. 8.2.1.2.2 Input Network
          3. 8.2.1.2.3 Gain
          4. 8.2.1.2.4 Output Network
        3. 8.2.1.3 Application Curves
      2. 8.2.2 Phono Preamplifier for Moving Magnet Cartridges
      3. 8.2.3 Single-Supply Electret Microphone Preamplifier
      4. 8.2.4 Composite Headphone Amplifier
      5. 8.2.5 Differential Line Receiver With AC-Coupled Outputs
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
        1. 8.4.1.1 Power Dissipation
      2. 8.4.2 Layout Example
  9. 9 Device and Documentation Support
    1. 9.1 Device Support
      1. 9.1.1 Development Support
        1. 9.1.1.1 PSpice® for TI
        2. 9.1.1.2 TINA-TI™ Simulation Software (Free Download)
        3. 9.1.1.3 DIP-Adapter-EVM
        4. 9.1.1.4 DIYAMP-EVM
        5. 9.1.1.5 TI Reference Designs
        6. 9.1.1.6 Filter Design Tool
    2. 9.2 Documentation Support
      1. 9.2.1 Related Documentation
    3. 9.3 Receiving Notification of Documentation Updates
    4. 9.4 Support Resources
    5. 9.5 Trademarks
    6. 9.6 Electrostatic Discharge Caution
    7. 9.7 Glossary
  10. 10Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

7.3.3 EMI Rejection Ratio (EMIRR)

The electromagnetic interference (EMI) rejection ratio, or EMIRR, describes the EMI immunity of operational amplifiers. An adverse effect that is common to many operational amplifiers is a change in the offset voltage as a result of RF signal rectification. An operational amplifier that is more efficient at rejecting this change in offset as a result of EMI has a higher EMIRR and is quantified by a decibel value. Measuring EMIRR can be performed in many ways, but this document provides the EMIRR IN+, which specifically describes the EMIRR performance when the RF signal is applied to the noninverting input pin of the operational amplifier. In general, only the noninverting input is tested for EMIRR for the following three reasons:

  • Operational amplifier input pins are known to be the most sensitive to EMI, and typically rectify RF signals better than the supply or output pins.
  • The noninverting and inverting operational amplifier inputs have symmetrical physical layouts and exhibit nearly matching EMIRR performance.
  • EMIRR is easier to measure on noninverting pins than on other pins because the noninverting input pin can be isolated on a printed-circuit-board (PCB). This isolation allows the RF signal to be applied directly to the noninverting input pin with no complex interactions from other components or connecting PCB traces.

A more formal discussion of the EMIRR IN+ definition and test method is shown in the EMI Rejection Ratio of Operational Amplifiers application report, available for download at www.ti.com.

The EMIRR IN+ of the OPA167x is plotted versus frequency in Figure 7-3. The dual and quad operational amplifier device versions have approximately identical EMIRR IN+ performance. The OPA167x unity-gain bandwidth is 16 MHz. EMIRR performance below this frequency denotes interfering signals that fall within the operational amplifier bandwidth.

GUID-1DA65631-B069-4845-8652-A7AEB02D2278-low.pngFigure 7-3 OPA167x EMIRR vs Frequency

Table 7-1 lists the EMIRR IN+ values for the OPA167x at particular frequencies commonly encountered in real-world applications. Applications listed in Table 7-1 can be centered on or operated near the particular frequency shown. This information can be of special interest to designers working with these types of applications, or working in other fields likely to encounter RF interference from broad sources, such as the industrial, scientific, and medical (ISM) radio band.

Table 7-1 OPA167x EMIRR IN+ for Frequencies of Interest
FREQUENCYAPPLICATION OR ALLOCATIONEMIRR IN+
400 MHzMobile radio, mobile satellite, space operation, weather, radar, UHF36 dB
900 MHzGSM, radio communication and navigation, GPS (to 1.6 GHz), ISM, aeronautical mobile, UHF42 dB
1.8 GHzGSM, mobile personal comm. broadband, satellite, L-band52 dB
2.4 GHz802.11b/g/n, Bluetooth™, mobile personal comm., ISM, amateur radio and satellite, S-band64 dB
3.6 GHzRadiolocation, aero comm./nav., satellite, mobile, S-band67 dB
5 GHz802.11a/n, aero communication and navigation, mobile communication, space and satellite operation, C-band77 dB