JAJSF23B March   2018  – July 2018 INA1620

PRODUCTION DATA.  

  1. 特長
  2. アプリケーション
  3. 概要
    1.     Device Images
      1.      INA1620の簡略化された内部回路図
      2.      FFT: 1kHz、32Ω負荷、50mW
  4. 改訂履歴
  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 Matched Thin-Film Resistor Pairs
      2. 7.3.2 Power Dissipation
      3. 7.3.3 Thermal Shutdown
      4. 7.3.4 EN Pin
      5. 7.3.5 GND Pin
      6. 7.3.6 Input Protection
    4. 7.4 Device Functional Modes
      1. 7.4.1 Shutdown Mode
      2. 7.4.2 Output Transients During Power Up and Power Down
  8. Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Noise Performance
      2. 8.1.2 Resistor Tolerance
      3. 8.1.3 EMI Rejection
      4. 8.1.4 EMIRR +IN Test Configuration
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
      3. 8.2.3 Application Curves
    3. 8.3 Other Application Examples
      1. 8.3.1 Preamplifier for Professional Microphones
  9. Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11デバイスおよびドキュメントのサポート
    1. 11.1 デバイス・サポート
      1. 11.1.1 開発サポート
        1. 11.1.1.1 TINA-TI(無料のダウンロード・ソフトウェア)
        2. 11.1.1.2 TI Precision Designs
    2. 11.2 ドキュメントのサポート
      1. 11.2.1 関連資料
    3. 11.3 ドキュメントの更新通知を受け取る方法
    4. 11.4 コミュニティ・リソース
    5. 11.5 商標
    6. 11.6 静電気放電に関する注意事項
    7. 11.7 Glossary
  12. 12メカニカル、パッケージ、および注文情報

EMI Rejection

The electromagnetic interference (EMI) rejection ratio, or EMIRR, describes the EMI immunity of operational amplifiers. An adverse effect that is common to many op amps is a change in the offset voltage as a result of RF signal rectification. An op amp 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 section provides the EMIRR IN+, which specifically describes the EMIRR performance when the RF signal is applied to the noninverting input pin of the op amp. In general, only the noninverting input is tested for EMIRR for the following three reasons:

  • Op amp 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 op amp inputs have symmetrical physical layouts and exhibit approximately 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 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.

High-frequency signals conducted or radiated to any pin of the operational amplifier result in adverse effects, as the amplifier does not have sufficient loop gain to correct for signals with spectral content outside its bandwidth. Conducted or radiated EMI on inputs, power supply, or output may result in unexpected DC offsets, transient voltages, or other unknown behavior. Take care to properly shield and isolate sensitive analog nodes from noisy radio signals and digital clocks and interfaces.

The EMIRR IN+ of the INA1620 amplifiers is plotted versus frequency as shown in Figure 53. See also EMI Rejection Ratio of Operational Amplifiers, available for download from www.ti.com.

INA1620 D033.gifFigure 53. INA1620 EMIRR IN+

Table 1 lists the EMIRR IN+ values for the INA1620 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. INA1620 EMIRR IN+ for Frequencies of Interest

FREQUENCY APPLICATION OR ALLOCATION EMIRR IN+
900 MHz Global system for mobile communications (GSM) applications, radio communication, navigation, GPS (to 1.6 GHz), GSM, aeronautical mobile, UHF applications 18 dB
1.8 GHz GSM applications, mobile personal communications, broadband, satellite, L-band (1 GHz to 2 GHz) 33 dB
2.4 GHz 802.11b, 802.11g, 802.11n, Bluetooth®, mobile personal communications, industrial, scientific and medical (ISM) radio band, amateur radio and satellite, S-band (2 GHz to 4 GHz) 26 dB
3.6 GHz Radiolocation, aero communication and navigation, satellite, mobile, S-band 40 dB
5 GHz 802.11a, 802.11n, aero communication and navigation, mobile communication, space and satellite operation, C-band (4 GHz to 8 GHz) 55 dB