SCPS207F May   2012  – November 2016 TCA9548A

PRODUCTION DATA.  

  1. Features
  2. Applications
  3. Description
  4. Revision History
  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 I2C Interface Timing Requirements
    7. 6.7 Reset Timing Requirements
    8. 6.8 Switching Characteristics
    9. 6.9 Typical Characteristics
  7. Parameter Measurement Information
  8. Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
    4. 8.4 Device Functional Modes
      1. 8.4.1 RESET Input
      2. 8.4.2 Power-On Reset
    5. 8.5 Programming
      1. 8.5.1 I2C Interface
      2. 8.5.2 Device Address
      3. 8.5.3 Bus Transactions
        1. 8.5.3.1 Writes
        2. 8.5.3.2 Reads
      4. 8.5.4 Control Register
      5. 8.5.5 RESET Input
      6. 8.5.6 Power-On Reset
  9. Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
    1. 10.1 Power-On Reset Requirements
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Documentation Support
      1. 12.1.1 Related Documentation
    2. 12.2 Receiving Notification of Documentation Updates
    3. 12.3 Community Resources
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

Features

  • 1-to-8 Bidirectional Translating Switches
  • I2C Bus and SMBus Compatible
  • Active-Low Reset Input
  • Three Address Pins, Allowing up to Eight TCA9548A Devices on the I2C Bus
  • Channel Selection Through an I2C Bus, In Any Combination
  • Power Up With All Switch Channels Deselected
  • Low RON Switches
  • Allows Voltage-Level Translation Between 1.8-V, 2.5-V, 3.3-V, and 5-V Buses
  • No Glitch on Power Up
  • Supports Hot Insertion
  • Low Standby Current
  • Operating Power-Supply Voltage Range of
    1.65 V to 5.5 V
  • 5-V Tolerant Inputs
  • 0- to 400-kHz Clock Frequency
  • Latch-Up Performance Exceeds 100 mA Per JESD 78, Class II
  • ESD Protection Exceeds JESD 22
    • ±2000-V Human-Body Model (A114-A)
    • 200-V Machine Model (A115-A)
    • ±1000-V Charged-Device Model (C101)

Applications

  • Servers
  • Routers (Telecom Switching Equipment)
  • Factory Automation
  • Products With I2C Slave Address Conflicts (Such as Multiple, Identical Temperature Sensors)

Description

The TCA9548A device has eight bidirectional translating switches that can be controlled through the I2C bus. The SCL/SDA upstream pair fans out to eight downstream pairs, or channels. Any individual SCn/SDn channel or combination of channels can be selected, determined by the contents of the programmable control register. These downstream channels can be used to resolve I2C slave address conflicts. For example, if eight identical digital temperature sensors are needed in the application, one sensor can be connected at each channel: 0-7.

The system master can reset the TCA9548A in the event of a time-out or other improper operation by asserting a low in the RESET input. Similarly, the power-on reset deselects all channels and initializes the I2C/SMBus state machine. Asserting RESET causes the same reset and initialization to occur without powering down the part. This allows recovery should one of the downstream I2C buses get stuck in a low state.

The pass gates of the switches are constructed so that the VCC pin can be used to limit the maximum high voltage, which is passed by the TCA9548A. Limiting the maximum high voltage allows the use of different bus voltages on each pair, so that 1.8-V, 2.5-V or 3.3-V parts can communicate with 5-V parts, without any additional protection. External pullup resistors pull the bus up to the desired voltage level for each channel. All I/O pins are 5-V tolerant.

Device Information(1)

PART NUMBER PACKAGE BODY SIZE (NOM)
TCA9548A TSSOP (24) 7.80 mm × 4.40 mm
VQFN (24) 4.00 mm × 4.00 mm
  1. For all available packages, see the orderable addendum at the end of the data sheet.

Simplified Application Diagram

TCA9548A simpschem_scps207.gif