SBOS826D December   2017  – October 2019 OPA207


  1. Features
  2. Applications
  3. Description
    1.     Device Images
      1.      Ultra-Low 0.1-Hz to 10-Hz Noise
  4. Revision History
  5. Pin Configuration and Functions
    1.     Pin Functions
  6. Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Typical Characteristics
  7. Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Operating Voltage
      2. 7.3.2 Input Protection
      3. 7.3.3 ESD Protection
      4. 7.3.4 Input Stage Linearization
      5. 7.3.5 Rail-to-Rail Output
      6. 7.3.6 Low Input Bias Current
      7. 7.3.7 Slew Boost
      8. 7.3.8 EMI Rejection Ratio (EMIRR)
    4. 7.4 Device Functional Modes
  8. Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 Typical OPA207 Application
        1. Design Requirements
        2. Detailed Design Procedure
        3. Application Curve
      2. 8.2.2 Precision Low-Side Current Sensing
      3. 8.2.3 Precision Buffer With Increased Output Current
  9. Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Development Support
        1. Webench Filter Designer Tool
        2. TINA-TI (Free Software Download)
        3. TI Precision Designs
    2. 11.2 Documentation Support
      1. 11.2.1 Related Documentation
    3. 11.3 Receiving Notification of Documentation Updates
    4. 11.4 Support Resources
    5. 11.5 Trademarks
    6. 11.6 Electrostatic Discharge Caution
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

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 report 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:

  1. 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.
  2. The noninverting and inverting operational amplifier inputs have symmetrical physical layouts and exhibit nearly matching EMIRR performance.
  3. EMIRR is easier to measure on noninverting pins than on other pins because the noninverting input terminal can be isolated on a printed circuit board (PCB). This isolation allows the RF signal to be applied directly to the noninverting input terminal with no complex interactions from other components or connecting PCB traces.
A more formal discussion of the EMIRR IN+ definition and test method is provided in TI Application Report EMI Rejection Ratio of Operational Amplifiers, available for download at The EMIRR IN+ of the OPA207 is plotted versus frequency as shown in Figure 46.

OPA207 EMIRR.gifFigure 46. OPA207 EMIRR IN+ vs Frequency

If available, any dual and quad operational amplifier device versions have nearly similar EMIRR IN+ performance. The OPA207 unity-gain bandwidth is 1 MHz. EMIRR performance below this frequency denotes interfering signals that fall within the operational amplifier bandwidth.

Table 1 shows the EMIRR IN+ values for the OPA207 at particular frequencies commonly encountered in real-world applications. Applications listed in Table 1 may be centered on or operated near the particular frequency shown. This information may 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 1. OPA207 EMIRR IN+ for Frequencies of Interest

400 MHz Mobile radio, mobile satellite/space operation, weather, radar, UHF 72 dB
900 MHz GSM, radio com/nav./GPS (to 1.6 GHz), ISM, aeronautical mobile, UHF 83 dB
1.8 GHz GSM, mobile personal comm. broadband, satellite, L-band 95 dB
2.4 GHz 802.11b/g/n, Bluetooth®, mobile personal comm., ISM, amateur radio/satellite, S-band 94 dB
3.6 GHz Radiolocation, aero comm./nav., satellite, mobile, S-band 103 dB
5 GHz 802.11a/n, aero comm./nav., mobile comm., space/satellite operation, C-band 102 dB