DUAL BIDIRECTIONAL I2C BUS AND SMBUS VOLTAGE-LEVEL TRANSLATOR

DESCRIPTION

The UTC  UCA9306 device is a dual bidirectional I

2

C 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 UTC UCA9306 device allows bidirectional voltage translations

between 1.2V and 5V,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 UTC UCA9306 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.

FEATURES

* 2-Bit Bidirectional Translator for SDA and SCL Lines in

Mixed-Mode I2C Applications * I2C and SMBus Compatible

* LessThan1.5-ns Maximum Propagation Delay to

Accommodate    Standard-Mode and Fast-Mode I2C Devices and Multiple Masters

* Allows Voltage-Level Translation Between

1.2V VREF1 and 1.8-V,2.5-V,3.3-V,or 5-V VREF2

1.8V VREF1 and 2.5-V,3.3-V,or 5-V VREF2

2.5V VREF1 and 3.3-V or 5-V VREF2

 .3V 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