SCAS582Q November   1996  – October 2014 SN74LVCHR16245A

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Simplified Schematic
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 Handling Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Switching Characteristics
    7. 6.7 Operating Characteristics
    8. 6.8 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
    4. 7.4 Device Functional Modes
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
      3. 8.2.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Trademarks
    2. 11.2 Electrostatic Discharge Caution
    3. 11.3 Glossary

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • DGG|48
  • DL|48
  • DGV|48
Thermal pad, mechanical data (Package|Pins)
Orderable Information

7 Detailed Description

7.1 Overview

This 16-bit (dual-octal) noninverting bus transceiver is designed for 1.65-V to 3.6-V VCC operation.

The SN74LVCHR16245A device is designed for asynchronous communication between data buses. The control-function implementation minimizes external-timing requirements.

This device can be used as two 8-bit transceivers or one 16-bit transceiver. It allows data transmission from the A bus to the B bus or from the B bus to the A bus, depending on the logic level at the direction-control (DIR) input. The output-enable (OE) input can disable the device so that the buses are effectively isolated.

All outputs, which are designed to sink up to 12 mA, include equivalent 26-Ω series resistors to reduce overshoot and undershoot.

Inputs can be driven from either 3.3-V or 5-V devices. This feature allows the use of this device as a translator in a mixed 3.3-V/5-V system environment.

To ensure the high-impedance state during power up or power down, OE should be tied to VCC through a pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver.

This device is fully specified for partial-power-down applications using Ioff. The Ioff circuitry disables the outputs, preventing damaging current backflow through the device when it is powered down.

Active bus-hold circuitry is provided to hold unused or floating data inputs at a valid logic level. Use of pullup or pulldown resistors with the bus-hold circuitry is not recommended. The bus-hold circuitry is part of the input circuit and is not disabled by OE or DIR.

7.2 Functional Block Diagram

ld_cas582.gifFigure 4. Logic Diagram (Positive Logic)

7.3 Feature Description

  • Wide operating voltage range
    • Operates from 1.65 V to 3.6 V
  • Allows down voltage translation
    • Inputs accept voltages to 5.5 V
  • Ioff feature
    • Allows voltages on the inputs and outputs when VCC is 0 V
  • All outputs have equivalent 26-Ω series resistors, so no external resistors are required
  • Bus hold on data inputs eliminates the need for external pullup or pulldown resistors

7.4 Device Functional Modes

Table 3. Function Table(1)
(Each 8-bit Section)

CONTROL INPUTS OUTPUT CIRCUITS OPERATION
OE DIR A PORT B PORT
L L Enabled Hi-Z B data to A bus
L H Hi-Z Enabled A data to B bus
H X Hi-Z Hi-Z Isolation
(1) Input circuits of the data I/Os always are active.