ZHCSH32 November   2017 TLA2021 , TLA2022 , TLA2024

PRODUCTION DATA.  

  1. 1 特性
  2. 2 应用
  3. 3 说明
    1.     Device Images
      1.      系统监控应用示例
  4. 4 修订历史记录
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and Functions
    1.     Pin Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 I2C Timing Requirements
    7. 7.7 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagrams
    3. 8.3 Feature Description
      1. 8.3.1 Multiplexer
      2. 8.3.2 Analog Inputs
      3. 8.3.3 Full-Scale Range (FSR) and LSB Size
      4. 8.3.4 Voltage Reference
      5. 8.3.5 Oscillator
      6. 8.3.6 Output Data Rate and Conversion Time
    4. 8.4 Device Functional Modes
      1. 8.4.1 Reset and Power-Up
      2. 8.4.2 Operating Modes
        1. 8.4.2.1 Single-Shot Conversion Mode
        2. 8.4.2.2 Continuous-Conversion Mode
    5. 8.5 Programming
      1. 8.5.1 I2C Interface
        1. 8.5.1.1 I2C Address Selection
        2. 8.5.1.2 I2C Interface Speed
        3. 8.5.1.3 Serial Clock (SCL) and Serial Data (SDA)
        4. 8.5.1.4 I2C Data Transfer Protocol
        5. 8.5.1.5 Timeout
        6. 8.5.1.6 I2C General-Call (Software Reset)
      2. 8.5.2 Reading and Writing Register Data
        1. 8.5.2.1 Reading Conversion Data or the Configuration Register
        2. 8.5.2.2 Writing the Configuration Register
      3. 8.5.3 Data Format
  9. 9 Register Maps
    1. 9.1 Conversion Data Register (RP = 00h) [reset = 0000h]
      1. Table 6. Conversion Data Register Field Descriptions
    2. 9.2 Configuration Register (RP = 01h) [reset = 8583h]
      1. Table 7. Configuration Register Field Descriptions
  10. 10Application and Implementation
    1. 10.1 Application Information
      1. 10.1.1 Basic Interface Connections
      2. 10.1.2 Connecting Multiple Devices
      3. 10.1.3 Single-Ended Signal Measurements
      4. 10.1.4 Analog Input Filtering
      5. 10.1.5 Duty Cycling To Reduce Power Consumption
      6. 10.1.6 I2C Communication Sequence Example
    2. 10.2 Typical Application
      1. 10.2.1 Design Requirements
      2. 10.2.2 Detailed Design Procedure
      3. 10.2.3 Application Curve
  11. 11Power Supply Recommendations
    1. 11.1 Power-Supply Sequencing
    2. 11.2 Power-Supply Decoupling
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Example
  13. 13器件和文档支持
    1. 13.1 器件支持
      1. 13.1.1 Third-Party Products Disclaimer
    2. 13.2 相关链接
    3. 13.3 接收文档更新通知
    4. 13.4 社区资源
    5. 13.5 商标
    6. 13.6 静电放电警告
    7. 13.7 Glossary
  14. 14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

10.1.4 Analog Input Filtering

Analog input filtering serves two purposes:

  1. Limits the effect of aliasing during the ADC sampling process
  2. Attenuates unwanted noise components outside the bandwidth of interest

In most cases, a first-order resistor capacitor (RC) filter is sufficient to completely eliminate aliasing or to reduce the effect of aliasing to a level within the noise floor of the sensor. A good starting point for a system design with the TLA202x is to use a differential RC filter with a cutoff frequency set somewhere between the selected output data rate and 25 kHz. Make the series resistor values as small as possible to reduce voltage drops across the resistors caused by the device input currents to a minimum. However, the resistors should be large enough to limit the current into the analog inputs to less than 10 mA in the event of an overvoltage. Then choose the differential capacitor value to achieve the target filter cutoff frequency. Common-mode filter capacitors to GND can be added as well, but should always be at least ten times smaller than the differential filter capacitor.

Figure 20 shows an example of filtering a differential signal (AIN0, AIN1), and a single-ended signal (AIN3). Equation 3 and Equation 4 show how to calculate the filter cutoff frequencies (fCO) in the differential and single-ended cases, respectively.

Equation 3. fCO DIF = 1 / (2π · 2 · RFLT · CDIF)
Equation 4. fCO SE = 1 / (2π · RFLT · CSE)