JAJSHX4D November   2012  – September 2019 ADS1018

PRODUCTION DATA.  

  1. 1 特長
  2. 2 アプリケーション
  3. 3 概要
    1.     Device Images
      1.      K タイプの熱電対測定 内蔵温度センサによる冷接点補償
  4. 4 改訂履歴
  5. 5 概要（続き）
  6. 6 Device Comparison Table
  7. 7 Pin Configuration and Functions
    1.     Pin Functions
  8. 8 Specifications
    1. 8.1 Absolute Maximum Ratings
    2. 8.2 ESD Ratings
    3. 8.3 Recommended Operating Conditions
    4. 8.4 Thermal Information
    5. 8.5 Electrical Characteristics
    6. 8.6 Timing Requirements: Serial Interface
    7. 8.7 Switching Characteristics: Serial Interface
    8. 8.8 Typical Characteristics
  9. 9 Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1 Multiplexer
      2. 9.3.2 Analog Inputs
      3. 9.3.3 Full-Scale Range (FSR) and LSB Size
      4. 9.3.4 Voltage Reference
      5. 9.3.5 Oscillator
      6. 9.3.6 Temperature Sensor
        1. 9.3.6.1 Converting from Temperature to Digital Codes
        2. 9.3.6.2 Converting from Digital Codes to Temperature
    4. 9.4 Device Functional Modes
      1. 9.4.1 Reset and Power-Up
      2. 9.4.2 Operating Modes
        1. 9.4.2.1 Single-Shot Mode and Power-Down
        2. 9.4.2.2 Continuous-Conversion Mode
      3. 9.4.3 Duty Cycling for Low Power
    5. 9.5 Programming
      1. 9.5.1 Serial Interface
      2. 9.5.2 Chip Select (CS)
      3. 9.5.3 Serial Clock (SCLK)
      4. 9.5.4 Data Input (DIN)
      5. 9.5.5 Data Output and Data Ready (DOUT/DRDY)
      6. 9.5.6 Data Format
      7. 9.5.7 Data Retrieval
        1. 9.5.7.1 32-Bit Data Transmission Cycle
        2. 9.5.7.2 16-Bit Data Transmission Cycle
    6. 9.6 Register Maps
      1. 9.6.1 Conversion Register [reset = 0000h]
        1. Table 4. Conversion Register Field Descriptions
      2. 9.6.2 Config Register [reset = 058Bh]
        1. Table 5. Config Register Field Descriptions
  10. 10Application and Implementation
    1. 10.1 Application Information
      1. 10.1.1 Serial Interface Connections
      2. 10.1.2 GPIO Ports for Communication
      3. 10.1.3 Analog Input Filtering
      4. 10.1.4 Single-Ended Inputs
      5. 10.1.5 Connecting Multiple Devices
      6. 10.1.6 Pseudo Code Example
    2. 10.2 Typical Application
      1. 10.2.1 Design Requirements
      2. 10.2.2 Detailed Design Procedure
      3. 10.2.3 Application Curves
  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デバイスおよびドキュメントのサポート
    1. 13.1 ドキュメントのサポート
      1. 13.1.1 関連資料
    2. 13.2 ドキュメントの更新通知を受け取る方法
    3. 13.3 コミュニティ・リソース
    4. 13.4 商標
    5. 13.5 静電気放電に関する注意事項
    6. 13.6 Glossary
  14. 14メカニカル、パッケージ、および注文情報

9.3.1 Multiplexer

The ADS1018 contains an input multiplexer (mux), as shown in Figure 8. Either four single-ended or two differential signals can be measured. Additionally, AIN0, AIN1, and AIN2 can be measured differentially to AIN3. The multiplexer is configured by bits MUX[2:0] in the Config register. When single-ended signals are measured, the negative input of the ADC is internally connected to GND by a switch within the multiplexer.

ADS1018 ai_fbd_mux_bas457.gifFigure 8. Input Multiplexer

When measuring single-ended inputs, the device does not output negative codes. These negative codes indicate negative differential signals; that is, (V(AINP) – V(AINN)) < 0. Electrostatic discharge (ESD) diodes to VDD and GND protect the ADS1018 inputs. To prevent the ESD diodes from turning on, keep the absolute voltage on any input within the range given in Equation 1:

Equation 1. GND – 0.3 V < V(AINx) < VDD + 0.3 V

If the voltages on the input pins can possibly violate these conditions, use external Schottky diodes and series resistors to limit the input current to safe values (see the Absolute Maximum Ratings table).

Also, overdriving one unused input on the ADS1018 may affect conversions currently taking place on other input pins. If overdriving unused inputs is possible, clamp the signal with external Schottky diodes.