2-Bit Bidirectional I2C Bus and SMBus Voltage-Level Shifter - PCA9306


2-Bit Bidirectional I2C Bus and SMBus Voltage-Level Shifter



The PCA9306 device is a dual bidirectional I2C and SMBus voltage-level translator with an enable (EN) input, and is operational from 1.2-V to 3.3-V VREF1 and 1.8-V to 5.5-V VREF2.

The PCA9306 device allows bidirectional voltage translations between 1.2 V and 5 V, without the use of a direction pin. The low ON-state resistance (RON) of the switch allows connections to be made with minimal propagation delay. When EN is high, the translator switch is ON, and the SCL1 and SDA1 I/O are connected to the SCL2 and SDA2 I/O, respectively, allowing bidirectional data flow between ports. When EN is low, the translator switch is off, and a high-impedance state exists between ports.

In addition to voltage translation, the PCA9306 device can be used to isolate a 400-kHz bus from a 100-kHz busby controlling the EN pin, and disconnecting the slower bus during fast-mode communication.


  • 2-Bit Bidirectional Translator for SDA and SCL
    Lines in Mixed-Mode I2C Applications
  • I2C and SMBus Compatible
  • Less Than 1.5-ns Maximum Propagation Delay to
    Accommodate Standard-Mode and Fast-Mode I2C
    Devices and Multiple Masters
  • Allows Voltage-Level Translation Between
    • 1.2-V VREF1 and 1.8-V, 2.5-V, 3.3-V,
      or 5-V VREF2
    • 1.8-V VREF1 and 2.5-V, 3.3-V,
      or 5-V VREF2
    • 2.5-V VREF1 and 3.3-V or 5-V VREF2
    • 3.3-V VREF1 and 5-V VREF2
  • Provides Bidirectional Voltage Translation With No
    Direction Pin
  • Low 3.5-Ω ON-State Resistance Between Input
    and Output Ports Provides Less Signal Distortion
  • Open-Drain I2C I/O Ports (SCL1, SDA1, SCL2,
    and SDA2)
  • 5-V Tolerant I2C I/O Ports to Support Mixed-Mode
    Signal Operation
  • High-Impedance SCL1, SDA1, SCL2, and SDA2
    Pins for EN = Low
  • Lockup-Free Operation for Isolation When
    EN = Low
  • Flow-Through Pinout for Ease of Printed-Circuit-
    Board Trace Routing
  • Latch-Up Performance Exceeds 100 mA Per
    JESD 78, Class II
  • ESD Protection Exceeds JESD 22
    • 2000-V Human-Body Model (A114-A)
    • 1000-V Charged-Device Model (C101)
    • I2C, SMBus, PMBus, MDIO, UART, Low-Speed
      SDIO, GPIO, and Other Two-Signal Interfaces
    • Servers
    • Routers (Telecom Switching Equipment)
    • Personal Computers
    • Industrial Automation

All other trademarks are the property of their respective owners

View more

Parametrics Compare all products in I2C Hub, Buffer, Repeater

No. of Outputs
Approx. Price (US$)
Operating Temperature Range (C)
Max Frequency (kHz)
Channel Width
Master Side I2C Bus Capacitance Supported (pF)
Slave Side I2C Bus Capacitance Supported (pF)
5V Tolerant I/O
Special Features
PCA9306 PCA9306-Q1 TCA9406
2    2    2   
0.20 | 1ku    0.23 | 1ku    0.30 | 1ku   
-40 to 85    -40 to 105
-40 to 85   
-40 to 85   
400    400    1000   
2    2     
400    400     
400    400     
Yes    Yes     
Enable Pin
Low Voltage
Open-Drain I/O Type
5V Tolerant I/O   
Enable Pin
Low Voltage
Open-Drain I/O Type
5V Tolerant I/O   
Enable Pin
Open-Drain I/O Type
5V Tolerant I/O
Push-Pull I/O Type   

Other qualified versions of PCA9306

Version Part Number Definition
Automotive PCA9306-Q1 Q100 devices qualified for high-reliability automotive applications targeting zero defects