SCES625A February   2005  – November 2015 SN74VMEH22501A-EP

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Description (continued)
  6. 6 Pin Configuration and Functions
  7. 7 Specifications
    1. 7.1  Absolute Maximum Ratings
    2. 7.2  ESD Ratings
    3. 7.3  Recommended Operating Conditions
    4. 7.4  Thermal Information
    5. 7.5  Electrical Characteristics
    6. 7.6  Live-Insertion Specifications
    7. 7.7  Timing Requirements for UBT Transceiver (I Version)
    8. 7.8  Switching Characteristics for Bus Transceiver Function (I Version)
    9. 7.9  Switching Characteristics for Bus Transceiver Function (M Version)
    10. 7.10 Switching Characteristics for UBT Transceiver (I Version)
    11. 7.11 Switching Characteristics for UBT Transceiver (M Version)
    12. 7.12 Switching Characteristics for Bus Transceiver Function (I Version)
    13. 7.13 Switching Characteristics for UBT (I Version)
    14. 7.14 Switching Characteristics for Bus Transceiver Function (I Version)
    15. 7.15 Switching Characteristics for UBT (I Version)
    16. 7.16 Skew Characteristics for Bus Transceiver (I Version)
    17. 7.17 Skew Characteristics for Bus Transceiver (M Version)
    18. 7.18 Skew Characteristics for UBT (I Version)
    19. 7.19 Skew Characteristics for UBT (M Version)
    20. 7.20 Skew Characteristics for Bus Transceiver (I Version)
    21. 7.21 Skew Characteristics for UBT (I Version)
    22. 7.22 Skew Characteristics for Bus Transceiver (I Version)
    23. 7.23 Skew Characteristics for UBT (I Version)
    24. 7.24 Maximum Data Transfer Rates
    25. 7.25 Typical Characteristics
  8. 8 Parameter Measurement Information
    1. 8.1 Distributed-Load Backplane Switching Characteristics
  9. 9 Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1 Functional Description for Two 1-Bit Bus Transceivers
      2. 9.3.2 Functional Description for 8-Bit UBT Transceiver
      3. 9.3.3 VMEbus Summary
    4. 9.4 Device Functional Modes
      1. 9.4.1 Direction Control Model (1-Bit Transceiver)
      2. 9.4.2 Direction Control for 8 Bit UBT
      3. 9.4.3 Latch Storage and Clock Storage
  10. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Application
      1. 10.2.1 Design Requirements
      2. 10.2.2 Detailed Design Procedure
      3. 10.2.3 Application Curves
  11. 11Power Supply Recommendations
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Example
  13. 13Device and Documentation Support
    1. 13.1 Device Support
      1. 13.1.1 Third-Party Products Disclaimer
    2. 13.2 Related Links
    3. 13.3 Community Resources
    4. 13.4 Trademarks
    5. 13.5 Electrostatic Discharge Caution
    6. 13.6 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

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発注情報

5 Description (continued)

The SN74VMEH22501A-EP device is pin-for-pin compatible to the SN74VMEH22501 device (SCES357), but operates at a wider operating temperature range.

High-speed backplane operation is a direct result of the improved OEC circuitry and high drive that has been designed and tested into the VME64x backplane model. The B-port I/Os are optimized for driving large capacitive loads and include pseudo-ETL input thresholds (½ VCC ±50 mV) for increased noise immunity. These specifications support the 2eVME protocols in VME64x (ANSI/VITA 1.1) and 2eSST protocols in VITA 1.5.

With proper design of a 21-slot VME system, a designer can achieve 320-MB transfer rates on linear backplanes and, possibly, 1-GB transfer rates on the VME320 backplane.

All inputs and outputs are 5-V tolerant and are compatible with TTL and 5-V CMOS inputs.

Active bus-hold circuitry holds unused or undriven 3A-port inputs at a valid logic state. Bus-hold circuitry is not provided on 1A or 2A inputs, any B-port input, or any control input. Use of pullup or pulldown resistors with the bus-hold circuitry is not recommended.

This device is fully specified for live-insertion applications using Ioff, power-up 3-state, and BIAS VCC. The Ioff circuitry prevents damaging current to backflow through the device when it is powered off/on. The power-up 3-state circuitry places the outputs in the high-impedance state during power up and power down, which prevents driver conflict. The BIAS VCC circuitry precharges and preconditions the B-port input/output connections, preventing disturbance of active data on the backplane during card insertion or removal, and permits true live-insertion capability.

When VCC is between 0 and 1.5 V, the device is in the high-impedance state during power up or power down. However, to ensure the high-impedance state above 1.5 V, output-enable (OE and OEBY) inputs should be tied to VCC through a pullup resistor and output-enable (OEAB) inputs should be tied to GND through a pulldown resistor; the minimum value of the resistor is determined by the drive capability of the device connected to this input.