Diodes Incorporated
Back to I2C Mux/Switch


2-Channel I2C/SMBus Bus Multiplexer

Contact Sales

Log in or register to manage email notifications about changes to datasheets or PCNs for this part.


The PI4MSD5V9540B is a 1-of-2 bidirectional translating multiplexer, controlled via the I2C/SMBus.

The SCL/SDA upstream pair fans out to two SCx/SDx downstream pairs, or channels. Only one SCx/SDx channel is selected at a time, determined by the contents of the programmable control register. A power-on reset function puts the registers in their default state and initializes the I2C/ SMBus. state machine with no channels selected. The pass gates of the multiplexer are constructed such that the VCC pin can be used to limit the maximum high voltage that is passed by the PI4MSD5V9540B. This allows the use of different bus voltages on each SCx/SDx pair, so that 1.2V, 1.8V, 2.5V or 3.3V parts can communicate with 5V parts without any additional protection. External pull-up resistors can pull the bus up to the desired voltage level for this channel. All I/O pins are 5V tolerant.


  • 1-of-2 bidirectional translating multiplexer
  • I2C-bus interface logic; compatible with SMBus standards
  • Operating power supply voltage range of 1.65V to 5.5
  • Allows voltage level translation between 1.2V, 1.8V, 2.5V, 3.3V and 5V buses
  • Low standby current
  • Low Ron switches
  • Channel selection via I2C-bus
  • Power-up with all multiplexer channels deselected
  • No glitch on power-up
  • Supports hot insertion
  • 5V tolerant inputs
  • 0 Hz to 400 kHz clock frequency
  • ESD protection exceeds 2000V HBM per JESD22-A114, and 1000 V CDM per JESD22-C101
  • Latch-up testing is done to JEDEC Standard JESD78 which exceeds 100 mA
  • Packages offered: SOIC (W8), MSOP (U8), TDFN2x3 (ZE8)

Product Specifications

Product Parameters

Ambient or Junction Temperature (°C) -40 to 85
Analog or Digital? Digital
Voltage 1.65V/5.5V
Single Ended Channels 2
Signal Type Single Ended
Configuration Multiplexer, 2-channel, 2:1
RailToRail 0
HotInsertion 1

Technical Documents

Design tool model software

Recommended Soldering Techniques


Additional Technical Documents are available upon request:
Application information, Evaluation board, and Other technical documents

Request Documents

Product Change Notices (PCNs)

A PCN may only apply to specific orderable part numbers in this datasheet. Please refer to the corresponding PCN to see the exact orderable part number(s) affected.

PCN # Issue Date Implementation Date Subject
PCN-2510 2021-02-26 2021-05-26 Qualified Additional A/T Sites, Fab Site and Data Sheet Change
PCN-2493 2020-12-28 2021-03-28 Qualified Additional A/T Sites and Bill of Materials (BOM)