TCA9406DCUR Logic - Translators, Level Shifters by Texas Instruments

The TCA9406 is a bidirectional 2-bit I2C/SMBus voltage-level translator with an output enable (OE) input. It operates between 1.65 V and 3.6 V on the Aside (referred to VCCA) and 2.3 V to 5.5 V on the B-side (linked to VCCB). This enables the device to interface between lower and higher logic signal levels when powered by any of the standard 1.8-V, 2.5-V, 3.3-V, and 5-V supply rails.
The OE input pin is referred to VCCA, can be directly connected to VCCA, and is also 5.5-V tolerant.
The OE pin can also be regulated and set to logic low to place all of the SCL and SDA pins in a high-impedance condition, reducing quiescent current usage dramatically. 
The TCA9406 may support up to 2 Mbps under regular I2C and SMBus operation or other open-drain setups; thus, it is compatible with standard I2C rates when the frequency of SCL is 100 kHz (Standard-mode), 400 kHz (Fast-mode), or 1 MHz (Fast mode Plus).
The TCA9406 can also be used as a general purpose level translator, and when both the A- and B-side ports are powered by push-pull devices, it can support up to 24 Mbps.Internal 10-k pullup resistors are provided on SCL A, SDA A, SCL B, and SDA B of the TCA9406. To minimize total pullup resistance and speed up rising edges, additional external pullup resistors can be connected to the bus. 
Features
• 2-Bit Bidirectional Translator for SDA and SCL Lines in I2C Applications
• Provides Bidirectional Voltage Translation With No Direction Pin
• High-Impedance Output SCL_A, SDA_A, SCL_B, SDA_B Pins When OE = Low or VCC = 0 V
• Internal 10-kΩ Pullup Resistor on All SDA and SCL Pins
• 1.65 V to 3.6 V on A port and 2.3 V to 5.5 V on B port (VCCA ≤ VCCB)
• VCC Isolation Feature: If Either VCC Input Is at GND, Both Ports Are in the High-Impedance State
• No Power-Supply Sequencing Required: Either VCCA or VCCB Can Be Ramped First
• Low Ioff of 2 µA When Either VCCA or VCCB = 0 V
• OE Input Can Be Tied Directly to VCCA Or Controlled By GPIO
• Latch-Up Performance Exceeds 100 mA Per JESD 78, Class II
• ESD Protection Exceeds JESD 22– A Port– 2500-V Human-Body Model (A114-B)– 250-V Machine Model (A115-A)– 1500-V Charged-Device Model (C101)– B Port– 8-kV Human-Body Model (A114-B)– 250-V Machine Model (A115-A)– 1500-V Charged-Device Model (C101) Applications
• I2C/SMBus
• UART
• GPIO