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PCA9543A

ACTIVE

2-channel 2.3- to 5.5-V I2C/SMBus switch with interrupt, reset & voltage translation

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TCA9543A ACTIVE 2-channel 1.65- to 5.5-V I2C/SMBus switch with interrupt, reset & voltage translation Performance enhancements for power-on reset and lower voltage operation.

Product details

Addresses 4 Supply voltage (max) (V) 5.5 Supply voltage (min) (V) 2.3 Features Interrupt pin, Reset pin Rating Catalog Frequency (max) (MHz) 0.4 Operating temperature range (°C) -40 to 85 Number of channels 2
Addresses 4 Supply voltage (max) (V) 5.5 Supply voltage (min) (V) 2.3 Features Interrupt pin, Reset pin Rating Catalog Frequency (max) (MHz) 0.4 Operating temperature range (°C) -40 to 85 Number of channels 2
SOIC (D) 14 51.9 mm² 8.65 x 6 TSSOP (PW) 14 32 mm² 5 x 6.4
  • 1-of-2 Bidirectional Translating Switches
  • I2C Bus and SMBus Compatible
  • Two Active-Low Interrupt Inputs
  • Active-Low Interrupt Output
  • Active-Low Reset Input
  • Two Address Pins Allowing up to Four PCA9543A 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 JESD78
  • ESD Protection Exceeds JESD 22
    • 2000-V Human-Body Model (A114-A)
    • 1000-V Charged-Device Model (C101)
  • 1-of-2 Bidirectional Translating Switches
  • I2C Bus and SMBus Compatible
  • Two Active-Low Interrupt Inputs
  • Active-Low Interrupt Output
  • Active-Low Reset Input
  • Two Address Pins Allowing up to Four PCA9543A 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 JESD78
  • ESD Protection Exceeds JESD 22
    • 2000-V Human-Body Model (A114-A)
    • 1000-V Charged-Device Model (C101)

The PCA9543A is a dual bidirectional translating switch controlled by the I2C bus. The SCL/SDA upstream pair fans out to two downstream pairs, or channels. Either individual SCn/SDn channel or both channels can be selected, determined by the contents of the programmable control register. Two interrupt inputs ( INT1INT0), one for each of the downstream pairs, are provided. One interrupt output ( INT) acts as an AND of the two interrupt inputs.

An active-low reset ( RESET) input allows the PCA9543A to recover from a situation where one of the downstream I2C buses is stuck in a low state. Pulling RESET low resets the I2C state machine and causes both of 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 PCA9543A. 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.

The PCA9543A is a dual bidirectional translating switch controlled by the I2C bus. The SCL/SDA upstream pair fans out to two downstream pairs, or channels. Either individual SCn/SDn channel or both channels can be selected, determined by the contents of the programmable control register. Two interrupt inputs ( INT1INT0), one for each of the downstream pairs, are provided. One interrupt output ( INT) acts as an AND of the two interrupt inputs.

An active-low reset ( RESET) input allows the PCA9543A to recover from a situation where one of the downstream I2C buses is stuck in a low state. Pulling RESET low resets the I2C state machine and causes both of 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 PCA9543A. 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.

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Technical documentation

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Type Title Date
* Data sheet PCA9543A 2-Channel I2C Bus Switch With Interrupt Logic and Reset datasheet (Rev. B) PDF | HTML 11 Mar 2021
Application note I2C Solutions for Hot Swap Applications (Rev. A) 31 Jan 2023
Application note I2C Dynamic Addressing 25 Apr 2019
Selection guide Logic Guide (Rev. AB) 12 Jun 2017
Application note Choosing the Correct I2C Device for New Designs PDF | HTML 07 Sep 2016
Application note Understanding and Interpreting Standard-Logic Data Sheets (Rev. C) 02 Dec 2015
Application note Understanding the I2C Bus PDF | HTML 30 Jun 2015
Application note Maximum Clock Frequency of I2C Bus Using Repeaters 15 May 2015
Application note I2C Bus Pull-Up Resistor Calculation PDF | HTML 13 Feb 2015
Application note Programming Fun Lights With TI's TCA6507 30 Nov 2007
Application note Semiconductor Packing Material Electrostatic Discharge (ESD) Protection 08 Jul 2004

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TSSOP (PW) 14 Ultra Librarian

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