SBOS844C May   2021  – March 2023 INA234

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  6. 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. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Integrated Analog-to-Digital Convertor (ADC)
      2. 7.3.2 Power Calculation
      3. 7.3.3 Low Bias Current
      4. 7.3.4 Low Voltage Supply and Wide Common-Mode Voltage Range
      5. 7.3.5 ALERT Pin
    4. 7.4 Device Functional Modes
      1. 7.4.1 Continuous Verses Triggered Operation
      2. 7.4.2 Device Shutdown
      3. 7.4.3 Power-On Reset
      4. 7.4.4 Averaging and Conversion Time Considerations
    5. 7.5 Programming
      1. 7.5.1 I2C Serial Interface
      2. 7.5.2 Writing to and Reading Through the I2C Serial Interface
      3. 7.5.3 High-Speed I2C Mode
      4. 7.5.4 General Call Reset
      5. 7.5.5 General Call Start Byte
      6. 7.5.6 SMBus Alert Response
    6. 7.6 Register Maps
      1. 7.6.1 Device Registers
  8. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Device Measurement Range and Resolution
      2. 8.1.2 Current and Power Calculations
      3. 8.1.3 ADC Output Data Rate and Noise Performance
      4. 8.1.4 Filtering and Input Considerations
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Select the Shunt Resistor
        2. 8.2.2.2 Configure the Device
        3. 8.2.2.3 Program the Shunt Calibration Register
        4. 8.2.2.4 Set Desired Fault Thresholds
        5. 8.2.2.5 Calculate Returned Values
      3. 8.2.3 Application Curves
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Example
  9. 9 Device and Documentation Support
    1. 9.1 Device Support
      1. 9.1.1 Development Support
    2. 9.2 Documentation Support
      1. 9.2.1 Related Documentation
    3. 9.3 Receiving Notification of Documentation Updates
    4. 9.4 Support Resources
    5. 9.5 Trademarks
    6. 9.6 Electrostatic Discharge Caution
    7. 9.7 Glossary
  10. 10Mechanical, Packaging, and Orderable Information

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • YBJ|8
Thermal pad, mechanical data (Package|Pins)
Orderable Information

7.5.1 I2C Serial Interface

The INA234 operates only as a target on both the SMBus and I2C interfaces. Connections to the bus are made through the open-drain SDA and SCL lines. The SDA and SCL pins feature integrated spike suppression filters and Schmitt triggers to minimize the effects of input spikes and bus noise. Although the device integrates spike suppression into the digital I/O lines, proper layout techniques help minimize the amount of coupling into the communication lines. This noise introduction could occur from capacitive coupling signal edges between the two communication lines themselves or from other switching noise sources present in the system. Routing traces in parallel with ground in between layers on a printed circuit board (PCB) typically reduces the effects of coupling between the communication lines. Shielded communication lines reduce the possibility of unintended noise coupling into the digital I/O lines that could be incorrectly interpreted as start or stop commands.

The INA234 supports the transmission protocol for fast mode up to 400 kHz and high-speed mode up to 2.94 MHz. All data bytes are transmitted most significant byte first and follow the SMBus 3.0 transfer protocol.

To communicate with the INA234, the controller must first address targets through a target address byte. The target address byte consists of seven address bits and a direction bit that indicates whether the action is to be a read or write operation.

The INA234 uses a single address pin, A0. Table 7-1 shows possible configurations for A0 and the corresponding address for both the A and B versions of the device. The INA234 samples the state of the A0 pin on every bus communication. The pin state for A0 must be established before any activity on the interface occurs. When connecting the SDA pin to A0 to set the device address, make sure to add an additional hold time of 100 ns on the MSB of the I2C address to ensure correct device addressing. The A and B device options, each with four unique addresses, allows users to connect up to eight devices in a system without I2C address conflicts.

Table 7-1 Address Pins and Target Addresses
A0 INA234A DEVICE OPTION INA234B DEVICE OPTION
GND 1000000 1001000
VS 1000001 1001001
SDA 1000010 1001010
SCL 1000011 1001011