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Product details

Parameters

Channels (#) 4 Addresses 4 Supply voltage (Max) (V) 5.5 Supply voltage (Min) (V) 2.3 Features Interrupt Pin, Reset Pin Frequency (Max) (kHz) 400 Operating temperature range (C) -40 to 85 open-in-new Find other I2C switches & multiplexers

Package | Pins | Size

SOIC (DW) 20 132 mm² 12.8 x 10.3 TSSOP (PW) 20 42 mm² 6.5 x 6.4 VQFN (RGY) 20 16 mm² 3.5 x 4.5 open-in-new Find other I2C switches & multiplexers

Features

  • 1-of-4 Bidirectional Translating Switches
  • I2C Bus and SMBus Compatible
  • Four Active-Low Interrupt Inputs
  • Active-Low Interrupt Output
  • Active-Low Reset Input
  • Two Address Terminals, Allowing up to Four 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)
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Description

The PCA9545A 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. Four interrupt inputs (INT3INT0), one for each of the downstream pairs, are provided. One interrupt (INT) output acts as an AND of the four interrupt inputs.

An active-low reset (RESET) input allows the PCA9545A 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 terminal can be used to limit the maximum high voltage, which will be passed by the PCA9545A. 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 terminals are 5.5 V tolerant.

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Same functionality and pinout but is not an equivalent to the compared device:
TCA9545A ACTIVE 4-Channel I2C and SMBus Switch With Interrupt Logic and Reset Functions TCA9545A is an enhanced version of the PCA9545A with an extended supply voltage range and performance enhancements related to Power-On Reset and Reset.

Technical documentation

= Top documentation for this product selected by TI
No results found. Please clear your search and try again. View all 11
Type Title Date
* Datasheet PCA9545A Low Voltage 4-channel I²C and SMbus Switch datasheet (Rev. D) Jun. 12, 2014
Application notes I2C Solutions for Hot Swap Applications Jan. 31, 2020
Application notes I2C Dynamic Addressing Apr. 25, 2019
Selection guides Logic Guide (Rev. AB) Jun. 12, 2017
Application notes Choosing the Correct I2C Device for New Designs Sep. 07, 2016
Application notes Understanding and Interpreting Standard-Logic Data Sheets (Rev. C) Dec. 02, 2015
Application notes Understanding the I2C Bus Jun. 30, 2015
Application notes Maximum Clock Frequency of I2C Bus Using Repeaters May 15, 2015
Application notes I2C Bus Pull-Up Resistor Calculation Feb. 13, 2015
Application notes Programming Fun Lights With TI's TCA6507 Nov. 30, 2007
Application notes Semiconductor Packing Material Electrostatic Discharge (ESD) Protection Jul. 08, 2004

Design & development

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Design tools & simulation

SIMULATION MODELS Download
SCPM005.ZIP (149 KB) - IBIS Model
SIMULATION TOOLS Download
PSpice® for TI design and simulation tool
PSPICE-FOR-TI — PSpice® for TI is a design and simulation environment that helps evaluate functionality of analog circuits. This full-featured, design and simulation suite uses an analog analysis engine from Cadence®. Available at no cost, PSpice for TI includes one of the largest model libraries in the (...)
Features
  • Leverages Cadence PSpice Technology
  • Preinstalled library with a suite of digital models to enable worst-case timing analysis
  • Dynamic updates ensure you have access to most current device models
  • Optimized for simulation speed without loss of accuracy
  • Supports simultaneous analysis of multiple products
  • (...)
SIMULATION TOOLS Download
SPICE-based analog simulation program
TINA-TI TINA-TI provides all the conventional DC, transient and frequency domain analysis of SPICE and much more. TINA has extensive post-processing capability that allows you to format results the way you want them. Virtual instruments allow you to select input waveforms and probe circuit nodes voltages (...)
document-generic User guide
DESIGN TOOLS Download
I2C designer tool
I2C-DESIGNER — Use the I2C Designer tool to quickly resolve conflicts in addressing, voltage level and frequency in I2C based designs. Enter master and slave inputs to automatically generate an I2C tree or easily build a custom solution. This tool will help designers save time and comply with the I2C standard with (...)
Features
  • GUI-based web application
  • Exportable designs
  • JSON file uploader
  • Bill of materials generator

CAD/CAE symbols

Package Pins Download
SOIC (DW) 20 View options
TSSOP (PW) 20 View options
VQFN (RGY) 20 View options

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