SN74AXC8T245RJWR Bus Transceiver: Schematic, Pinout, and Datasheet

The SN74AXC8T245RJWR is an 8-bit non-inverting bus transceiver that corrects voltage level mismatches between devices running at the most recent 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.

Two independent power supply rails (VCCA and VCCB) run at as low as 0.65 V to power the gadget. A1 through A8 are data pins that track VCCA, which accepts any source voltage between 0.65 and 3.6 V. VCCB, which accepts any supply voltage between 0.65 V and 3.6 V, is tracked by data pins B1 through B8.

The SN74AXC8T245RJWR device is intended for asynchronous data bus connections. Depending on the logic level of the direction-control inputs (DIR1 and DIR2), the device transfers data from the A bus to the B bus or from the B bus to the A bus. The output-enable (OE) input is used to disable the outputs, thus isolating the buses.

The control pins (DIR and OE) of the SN74AXC8T245RJWR device are referred to VCCA.

This device is completely qualified for Ioff-based partial-power-down applications. When the device is turned off, the Ioff circuitry shuts the outputs. This prevents current backflow into the device, preventing device damage.

If each VCC input supply falls below 100 mV, the VCC isolation function disables all level shifter outputs and places them in a high-impedance condition.

OE should be coupled to VCCA through a pullup resistor to assure the high-impedance condition of the level shifter  I/Os during power up or power down; the minimum value of the resistor is decided by the driver's current-sinking capabilities.

Pinout

The following show SN74AXC8T245RJWR Symbol, Footprint and 3D Model.

Symbol

Footprint

3D Model

• 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

• 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 SN74AVC8T245 and 74AVC8T245 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

The following figure is SN74AXC8T245RJWR Functional Block Diagram.

Functional Block Diagram

The SN74AXC8T245RJWR Typical Application Schematics are shown as follows.

Typical Application Schematic

Follow standard printed-circuit board layout principles to ensure device reliability.

• On power supplies, use bypass capacitors.

• To avoid excessive loading, use short trace lengths.

• Depending on the system needs, place pads on the signal channels for loading capacitors or pullup resistors to help regulate the signal rise and fall times.

Layout

• Enterprise and Communications

• Industrial

• Personal Electronics

• Wireless Infrastructure

• Building Automation

• Point of Sale

The following figure is SN74AXC8T245RJWR Package.

Package

Texas Instruments Incorporated (TI) is an American technology corporation based in Dallas, Texas, that creates and manufactures semiconductors and integrated circuits for sale to electronics designers and manufacturers across the world. Based on sales volume, it is among the top ten semiconductor businesses in the world. More than 80% of the company's income comes from analog chips and embedded CPUs. In addition to calculators, microcontrollers, and multi-core computers, TI manufactures TI digital light processing technologies and education technology.