ZHCSE76E December   2011  – December 2022 ADS1113-Q1 , ADS1114-Q1 , ADS1115-Q1

PRODUCTION DATA  

  1. 特性
  2. 应用
  3. 说明
  4. Revision History
    1.     Device Comparison Table
  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
    5. 6.5 Electrical Characteristics
    6. 6.6 Timing Requirements: I2C
    7. 6.7 Timing Diagram
    8. 6.8 Typical Characteristics
  7. Parameter Measurement Information
    1. 7.1 Noise Performance
  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
      7. 8.3.7 Digital Comparator (ADS1114-Q1 and ADS1115-Q1 Only)
      8. 8.3.8 Conversion Ready Pin (ADS1114-Q1 and ADS1115-Q1 Only)
      9. 8.3.9 SMbus 警报响应
    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 Mode
        2. 8.4.2.2 Continuous-Conversion Mode
      3. 8.4.3 Duty Cycling For Low Power
    5. 8.5 Programming
      1. 8.5.1 I2C Interface
        1. 8.5.1.1 I2C Address Selection
        2. 8.5.1.2 I2C General Call
        3. 8.5.1.3 I2C Speed Modes
      2. 8.5.2 Target Mode Operations
        1. 8.5.2.1 Receive Mode
        2. 8.5.2.2 Transmit Mode
      3. 8.5.3 Writing To and Reading From the Registers
      4. 8.5.4 Data Format
    6. 8.6 Register Map
      1. 8.6.1 Address Pointer Register (address = N/A) [reset = N/A]
      2. 8.6.2 Conversion Register (P[1:0] = 00b) [reset = 0000h]
      3. 8.6.3 Config Register (P[1:0] = 01b) [reset = 8583h]
      4. 8.6.4 Lo_thresh (P[1:0] = 10b) [reset = 8000h] and Hi_thresh (P[1:0] = 11b) [reset = 7FFFh] Registers
  9. Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Basic Connections
      2. 9.1.2 Single-Ended Inputs
      3. 9.1.3 Input Protection
      4. 9.1.4 Unused Inputs and Outputs
      5. 9.1.5 Analog Input Filtering
      6. 9.1.6 Connecting Multiple Devices
      7. 9.1.7 Quick-Start Guide
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Shunt Resistor Considerations
        2. 9.2.2.2 Operational Amplifier Considerations
        3. 9.2.2.3 ADC Input Common-Mode Considerations
        4. 9.2.2.4 Resistor (R1, R2, R3, R4) Considerations
        5. 9.2.2.5 Noise and Input Impedance Considerations
        6. 9.2.2.6 First-Order RC Filter Considerations
        7. 9.2.2.7 Circuit Implementation
        8. 9.2.2.8 Results Summary
      3. 9.2.3 Application Curves
    3. 9.3 Power Supply Recommendations
      1. 9.3.1 Power-Supply Sequencing
      2. 9.3.2 Power-Supply Decoupling
    4. 9.4 Layout
      1. 9.4.1 Layout Guidelines
      2. 9.4.2 Layout Example
  10. 10Device and Documentation Support
    1. 10.1 Documentation Support
      1. 10.1.1 Related Documentation
    2. 10.2 接收文档更新通知
    3. 10.3 支持资源
    4. 10.4 Trademarks
    5. 10.5 Electrostatic Discharge Caution
    6. 10.6 术语表
  11. 11Mechanical, Packaging, and Orderable Information

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订购信息

I2C Interface

The ADS111x-Q1 communicate through an I2C interface. I2C is a two-wire open-drain interface that supports multiple devices and controllers on a single bus. Devices on the I2C bus only drive the bus lines low by connecting them to ground; the devices never drive the bus lines high. Instead, the bus wires are pulled high by pullup resistors, so the bus wires are always high when no device is driving them low. As a result of this configuration, two devices cannot conflict. If two devices drive the bus simultaneously, there is no driver contention.

Communication on the I2C bus always takes place between two devices, one acting as the controller and the other as the target. Both the controller and target can read and write, but the target can only do so under the direction of the controller. Some I2C devices can act as a controller or target, but the ADS111x-Q1 can only act as a target device.

An I2C bus consists of two lines: SDA and SCL. SDA carries data; SCL provides the clock. All data are transmitted across the I2C bus in groups of eight bits. To send a bit on the I2C bus, drive the SDA line to the appropriate level while SCL is low (a low on SDA indicates the bit is zero; a high indicates the bit is one). After the SDA line settles, the SCL line is brought high, then low. This pulse on SCL clocks the SDA bit into the receiver shift register. If the I2C bus is held idle for more than 25 ms, the bus times out.

The I2C bus is bidirectional; that is, the SDA line is used for both transmitting and receiving data. When the controller reads from a target, the target drives the data line; when the controller writes to a target, the controller drives the data line. The controller always drives the clock line. The ADS111x-Q1 cannot act as a controller, and therefore can never drive SCL.

Most of the time the bus is idle; no communication occurs, and both lines are high. When communication takes place, the bus is active. Only a controller device can start a communication and initiate a START condition on the bus. Normally, the data line is only allowed to change state when the clock line is low. If the data line changes state when the clock line is high, this change is either a START condition or a STOP condition. A START condition occurs when the clock line is high, and the data line goes from high to low. A STOP condition occurs when the clock line is high, and the data line goes from low to high.

After the controller issues a START condition, the controller sends a byte that indicates which target device to communicate with. This byte is called the address byte. Each device on an I2C bus has a unique 7-bit address that the device responds to. The controller sends an address in the address byte, together with a bit that indicates whether the controller wishes to read from or write to the target device.

Every byte (address and data) transmitted on the I2C bus is acknowledged with an acknowledge bit. When the controller finishes sending a byte (eight data bits) to a target, the controller stops driving SDA and waits for the target to acknowledge the byte. The target acknowledges the byte by pulling SDA low. The controller then sends a clock pulse to clock the acknowledge bit. Similarly, when the controller completes reading a byte, the controller pulls SDA low to acknowledge this completion to the target. The controller then sends a clock pulse to clock the bit. The controller always drives the clock line.

If a device is not present on the bus, and the controller attempts to address the device, the controller receives a not-acknowledge because no device is present at that address to pull the line low. A not-acknowledge is performed by simply leaving SDA high during an acknowledge cycle.

When the controller has finished communicating with a target, the controller can issue a STOP condition. When a STOP condition is issued, the bus becomes idle again. The controller can also issue another START condition. When a START condition is issued while the bus is active, this condition is called a repeated start condition.

The Timing Requirements section shows a timing diagram for the ADS111x-Q1 I2C communication.