SCPS148G OCTOBER   2005  – May 2016 PCA9546A

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 Electrical Characteristics
    5. 6.5 I2C Interface Timing Requirements
    6. 6.6 Interrupt and Reset Timing Requirements
    7. 6.7 Switching 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
        1. 8.4.1.1 RESET Errata
      2. 8.4.2 Power-On Reset
    5. 8.5 Programming
      1. 8.5.1 I2C Interface
    6. 8.6 Control Register
      1. 8.6.1 Device Address
      2. 8.6.2 Control Register Description
      3. 8.6.3 Control Register Definition
  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 PCA9546A Application Curves
  10. 10Power Supply Recommendations
    1. 10.1 Power-On Reset Errata
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Electrostatic Discharge Caution
    2. 12.2 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

1 Features

  • 1-of-4 Bidirectional Translating Switches
  • I2C Bus and SMBus Compatible
  • Active-Low Reset Input
  • Three Address Pins, Allowing up to Eight PCA9546A Devices on the I2C Bus
  • Channel Selection Via 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 2.3 V to 5.5 V
  • 5.5 V Tolerant Inputs
  • 0 to 400-kHz Clock Frequency
  • Latch-Up Performance Exceeds 100 mA Per JESD 78
  • ESD Protection Exceeds JESD 22
    • 2000-V Human-Body Model (A114-A)
    • 1000-V Charged-Device Model (C101)

2 Applications

  • Servers
  • Routers (Telecom Switching Equipment)
  • Factory Automation
  • Products With I2C Slave Address Conflicts
    (for example. Multiple, Identical Temp Sensors)

3 Description

The PCA9546A is a quad bidirectional translating switch controlled via the I2C bus. The SCL/SDA upstream pair fans out to four 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.

An active-low reset (RESET) input allows the PCA9546A to recover from a situation in which one of the downstream I2C buses is stuck in a low state. Pulling RESET low resets the I2C state machine and causes all the channels to be deselected, as does the internal power-on reset function.

The pass gates of the switches are constructed such that the VCC pin can be used to limit the maximum high voltage, which will be passed by the PCA9546A. This 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 pull-up resistors pull the bus up to the desired voltage level for each channel. All I/O pins are 5.5-V tolerant.

Device Information(1)

PART NUMBER PACKAGE BODY SIZE (NOM)
PCA9546A TSSOP (16) 5.00 mm x 4.40 mm
(1) For all available packages, see the orderable addendum at the end of the datasheet.

Simplified Application Diagram

PCA9546A pg1_simp_scps148.gif