SCPS207H May   2012  – September 2024 TCA9548A

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 I2C Interface Timing Requirements
    7. 5.7 Reset Timing Requirements
    8. 5.8 Switching Characteristics
    9. 5.9 Typical Characteristics
  7. 6 Parameter Measurement Information
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
    4. 7.4 Device Functional Modes
      1. 7.4.1 RESET Input
      2. 7.4.2 Power-On Reset
    5. 7.5 Programming
      1. 7.5.1 I2C Interface
      2. 7.5.2 Device Address
      3. 7.5.3 Bus Transactions
        1. 7.5.3.1 Writes
        2. 7.5.3.2 Reads
      4. 7.5.4 Control Register
      5. 7.5.5 RESET Input
      6. 7.5.6 Power-On Reset
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
      3. 8.2.3 Application Curves
    3. 8.3 Power Supply Recommendations
      1. 8.3.1 Power-On Reset Requirements
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 Documentation Support
      1. 9.1.1 Related Documentation
    2. 9.2 Receiving Notification of Documentation Updates
    3. 9.3 Support Resources
    4. 9.4 Trademarks
    5. 9.5 Electrostatic Discharge Caution
    6. 9.6 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

Package Options

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

7.5.1 I2C Interface

The TCA9548A has a standard bidirectional I2C interface that is controlled by a controller device in order to be configured or read the status of this device. Each target on the I2C bus has a specific device address to differentiate between other target devices that are on the same I2C bus. Many target devices require configuration upon startup to set the behavior of the device. This is typically done when the controller accesses internal register maps of the target, which have unique register addresses. A device can have one or multiple registers where data is stored, written, or read.

The physical I2C interface consists of the serial clock (SCL) and serial data (SDA) lines. Both SDA and SCL lines must be connected to VCC through a pull-up resistor. The size of the pull-up resistor is determined by the amount of capacitance on the I2C lines. (For further details, see the I2C Pull-up Resistor Calculation application report. Data transfer may be initiated only when the bus is idle. A bus is considered idle if both SDA and SCL lines are high after a STOP condition (See Figure 7-1 and Figure 7-2).

The following is the general procedure for a controller to access a target device:

  1. If a controller wants to send data to a target:
    • Controller-transmitter sends a START condition and addresses the target-receiver.
    • Controller-transmitter sends data to target-receiver.
    • Controller-transmitter terminates the transfer with a STOP condition.
  2. If a controller wants to receive or read data from a target:
    • Controller-receiver sends a START condition and addresses the target-transmitter.
    • Controller-receiver sends the requested register to read to target-transmitter.
    • Controller-receiver receives data from the target-transmitter.
    • Controller-receiver terminates the transfer with a STOP condition.
TCA9548A Definition of Start and Stop ConditionsFigure 7-1 Definition of Start and Stop Conditions
TCA9548A Bit TransferFigure 7-2 Bit Transfer