1 Features

1• Qualified Fully Configurable Dual-Rail Design

Allows Each Port to Operate With a Power Supply

Range From 0.65 V to 3.6 V

• Operating Temperature From –40°C to +125°C

• Bus-hold on Data Inputs Eliminates the Need for

External Pullup or Pulldown Resistors

• Multiple Direction Control Pins to Allow

Simultaneous Up and Down Translation

• Up to 380 Mbps support when translating from 1.8

V to 3.3 V

• VCC Isolation Feature to Effectively Isolate Both

Buses in a Power-Down Scenario

• Partial Power-Down Mode to Limit Backflow

Current in a Power-Down Scenario

• Compatible With SN74AVCH8T245 and

74AVCH8T245 Level Shifters

• Latch-Up Performance Exceeds 100 mA Per

JESD 78, Class II

• ESD Protection Exceeds JESD 22

– 8000-V Human-Body Model

– 1000-V Charged-Device Model

2 Applications

• Enterprise and Communications

• Wireless Infrastructure

• Building Automation

• Data Center Switches

• Enterprise-Solid State Drive

• Rack Server

• EPOS

3 Description

The SN74AXCH8T245 device is an 8-bit noninverting

bus transceiver that resolves voltage level

mismatch between devices operating at the latest

voltage nodes (0.7 V, 0.8 V, and 0.9 V) and devices

operating at industry standard voltage nodes (1.8 V,

2.5 V, 3.3 V) and vice versa.

The device operates by using two independent

power-supply rails (VCCA and VCCB) . Data pins A1

through A8 are designed to track VCCA, which accepts

any supply voltage from 0.65 V to 3.6 V. Data pins B1

through B8 are designed to track VCCB, which accepts

any supply voltage from 0.65 V to 3.6 V. Additionally

the SN74AXCH8T245 is compatible with a singlesupply

system.

The SN74AXCH8T245 device is designed for

asynchronous communication between data buses.

The device transmits data from the A bus to the B

bus or from the B bus to the A bus, depending on the

logic level of the direction-control inputs (DIR1 and

DIR2). The output-enable (OE) input is used to

disable the outputs so the buses are effectively

isolated.

The SN74AXCH8T245 device is designed so the

control pins (DIR and OE) are referenced to VCCA.

Active bus-hold circuitry holds unused or undriven

inputs at a valid logic state. Use of pull-up or pulldown

resistors with the bus-hold circuitry is not

recommended. If a supply is present for VCCA or

VCCB, the bus-hold circuitry always remains active on

all A and B ports respectively, independent of the

direction control or output enable.

This device is fully specified for partial-power-down

applications using Ioff. The Ioff circuitry disables the

outputs when the device is powered down. This

inhibits current backflow into the device which

prevents damage to the device.

The VCC isolation feature ensures that if either VCC

input supply is below 100 mV, all level shifter outputs

are disabled and placed into a high-impedance state.

To ensure the high-impedance state of the level

shifter I/Os during power up or power down, OE

should be tied to VCCA through a pull-up resistor; the

minimum value of the resistor is determined by the

current-sinking capability of the driver.