ZHCSIQ4B September   2018  – December 2018 OPA828

PRODUCTION DATA.  

  1. 特性
  2. 应用
  3. 说明
    1.     Device Images
      1.      开环增益和相位与频率间的关系
      2.      失调电压漂移
  4. 修订历史记录
  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 Characteristics
      2. 7.3.2  Phase-Reversal Protection
      3. 7.3.3  Electrical Overstress
      4. 7.3.4  MUX Friendly Inputs
      5. 7.3.5  Overload Power Limiter
      6. 7.3.6  Capacitive Load and Stability
      7. 7.3.7  Capacitive Load and Stability
      8. 7.3.8  Settling Time
      9. 7.3.9  Slew Rate
      10. 7.3.10 Full Power Bandwidth
      11. 7.3.11 Small Signal Response
      12. 7.3.12 Thermal Considerations
      13. 7.3.13 Thermal Shutdown
      14. 7.3.14 Low Noise
      15. 7.3.15 Low Offset Voltage Drift
      16. 7.3.16 Overload Recovery
    4. 7.4 Device Functional Modes
      1. 7.4.1 Functional Modes
  8. Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 Typical Application: SAR ADC Driver
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
        3. 8.2.1.3 Application Curves
      2. 8.2.2 Typical Application: Low-Pass Filter
        1. 8.2.2.1 Design Requirements
        2. 8.2.2.2 Detailed Design Procedure
        3. 8.2.2.3 Application Curve
  9. Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11器件和文档支持
    1. 11.1 器件支持
      1. 11.1.1 开发支持
    2. 11.2 文档支持
      1. 11.2.1 相关文档
    3. 11.3 接收文档更新通知
    4. 11.4 社区资源
    5. 11.5 商标
    6. 11.6 静电放电警告
    7. 11.7 术语表
  12. 12机械、封装和可订购信息

封装选项

机械数据 (封装 | 引脚)
散热焊盘机械数据 (封装 | 引脚)
订购信息

MUX Friendly Inputs

Multiplexing is a frequently-used technique to perform data acquisition in multi-channel systems with minimal signal-chain requirements. In this context, the role of the multiplexer (MUX) in an acquisition system is to switch between channels and send each signal as fast as possible to a single data converter — maximizing system throughput and minimizing delay. To ensure accurate processing, a precision amplifier is placed downstream from the multiplexer to precisely drive the analog-to-digital converter (ADC). This concept is illustrated in Figure 45.

OPA828 MUX_Friendly.gifFigure 45. Typical Multiplexed System Block Diagram

In a typical multiplexed application it is common that large transient voltages can be presented to the input of the op amp driving the ADC. Large input differential voltages are commonly seen during slewing or open-loop operation, which is especially common when switching from one MUX input to another. Traditional precision amplifiers often consist of a differential transistor pair that is protected from large differential transient input voltages with anti-parallel diodes between the inputs of the amplifier. These anti-parallel diodes are effective at limiting the voltage differential between the inputs to one or two forward diode voltage drops, which protects the precision input devices from damage. However, the anti-parallel diodes do have considerable drawbacks such as large inrush currents when they are turned on. lf passive filtering or high source impedance is present, large inrush current can disturb settling time, limiting the throughput of the system and degrading signal-chain precision. The OPA828 does not need anti-parallel diodes to protect the input JFET transistors and is free from large inrush currents even with differential input voltages as large as ±18 V. These concepts are illustrated in Figure 46:

OPA828 anti_parallel_diodes.gifFigure 46. Typical Multiplexed System Block Diagram