JAJSEY8A March   2018  – January 2021 OPA197-Q1 , OPA2197-Q1 , OPA4197-Q1

PRODUCTION DATA  

  1. 特長
  2. アプリケーション
  3. 概要
  4. Revision History
  5. Pin Configuration and 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: OPA197-Q1
    5. 6.5 Thermal Information: OPA2197-Q1
    6. 6.6 Thermal Information: OPA4197-Q1
    7. 6.7 Electrical Characteristics: VS = ±4 V to ±18 V (VS = 8 V to 36 V)
    8. 6.8 Electrical Characteristics: VS = ±2.25 V to ±4 V (VS = 4.5 V to 8 V)
    9. 6.9 Typical Characteristics
  7. Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Input Protection Circuitry
      2. 7.3.2 EMI Rejection
      3. 7.3.3 Phase Reversal Protection
      4. 7.3.4 Thermal Protection
      5. 7.3.5 Capacitive Load and Stability
      6. 7.3.6 Common-Mode Voltage Range
      7. 7.3.7 Electrical Overstress
      8. 7.3.8 Overload Recovery
    4. 7.4 Device Functional Modes
  8. Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 16-Bit Precision Multiplexed Data-Acquisition System
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
        3. 8.2.1.3 Application Curve
      2. 8.2.2 Slew-Rate Limit for Input Protection
      3. 8.2.3 Precision Reference Buffer
  9. Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Examples
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Development Support
        1. 11.1.1.1 TINA-TI™ Simulation Software (Free Download)
        2. 11.1.1.2 TI Precision Designs
    2. 11.2 Documentation Support
      1. 11.2.1 Related Documentation
    3. 11.3 ドキュメントの更新通知を受け取る方法
    4. 11.4 サポート・リソース
    5. 11.5 Trademarks
    6. 11.6 静電気放電に関する注意事項
    7. 11.7 用語集
  12. 12Mechanical, Packaging, and Orderable Information

パッケージ・オプション

メカニカル・データ(パッケージ|ピン)
サーマルパッド・メカニカル・データ
発注情報

Detailed Design Procedure

The purpose of this precision design is to design an optimal high voltage multiplexed data acquisition system for highest system linearity and fast settling. The overall system block diagram is illustrated in GUID-17545A77-83AA-4BFA-822A-FC546E5EAB9E.html#SBOS6209312. The circuit is a multichannel data acquisition signal chain consisting of an input low-pass filter, mux, mux output buffer, attenuating SAR ADC driver, digital counter for mux and the reference driver. The architecture allows fast sampling of multiple channels using a single ADC, providing a low-cost solution. The two primary design considerations to maximize the performance of a precision multiplexed data acquisition system are the mux input analog front-end and the high-voltage level translation SAR ADC driver design. However, carefully design each analog circuit block based on the ADC performance specifications in order to achieve the fastest settling at 16-bit resolution and lowest distortion system. GUID-17545A77-83AA-4BFA-822A-FC546E5EAB9E.html#SBOS6209312 includes the most important specifications for each individual analog block.

This design systematically approaches each analog circuit block to achieve a 16-bit settling for a full-scale input stage voltage and linearity for a 10-kHz sinusoidal input signal at each input channel. The first step in the design is to understand the requirement for extremely low impedance input-filter design for the mux. This understanding helps in the decision of an appropriate input filter and selection of a mux to meet the system settling requirements. The next important step is the design of the attenuating analog front-end (AFE) used to level translate the high-voltage input signal to a low-voltage ADC input when maintaining amplifier stability. The next step is to design a digital interface to switch the mux input channels with minimum delay. The final design challenge is to design a high-precision, reference-driver circuit that provides the required REFP reference voltage with low offset, drift, and noise contributions.

For step-by-step design procedure, circuit schematics, bill of materials, PCB files, simulation results, and test results, refer to TI Precision Design TIPD151, 16-bit, 400-kSPS, 4-Channel, Multiplexed Data Acquisition System for High Voltage Inputs with Lowest Distortion.