SCLA017A July   2019  – April 2021 SN74HC595

 

  1.   Trademarks
  2. 1Block Diagram
  3. 2Optimizing System Controller I/O Usage
  4. 3Logic and Translation Use Cases
    1. 3.1 Logic Use Cases
      1. 3.1.1 Combine Power Good Signals
      2. 3.1.2 Debounce Switches and Buttons
      3. 3.1.3 Increase Number of Controller Inputs
      4. 3.1.4 Increase Number of Controller Outputs
    2. 3.2 Voltage Translation Use Cases
      1. 3.2.1 SPI Communication
      2. 3.2.2 RMII Communication
  5. 4Recommended Logic and Translation Families for Network Switches
    1. 4.1 AXC: Advanced eXtremely Low-Voltage CMOS Translation
    2. 4.2 LVC: Low-Voltage CMOS Logic and Translation
    3. 4.3 HC: High-speed CMOS Logic
  6. 5Revision History

1 Optimizing Network Switch Designs with Common Logic Use Cases

Network switches (switches for wireless and wired infrastructure) integrate numerous subsystems together that are dedicated to high data throughput communication critical to the next-generation of internet, cloud, and 5G solutions. Though the switches differ in bandwidth and external interfaces, they share similar digital interfacing challenges; such as differing voltage domains between management CPUs and switch-fabric ASICS as well as a lack of GPIO pins for either LED control or communication QSFP module signals. All of the use cases shown in the Block Diagram and Logic and Translation Use Cases sections of this document are commonly seen in Network Switch designs.

Logic gates, voltage translators, and other logic devices are utilized for many purposes throughout modern electronic systems. This document provides example solutions for common design challenges that can be solved using logic and translation. Not all of the solutions here appear in every system; all solutions shown, however, are commonly used and effective.

There are dozens of logic families available from Texas Instruments, and it can be difficult to select the right one for the application. Network switches can very in size and in complexity, but the key design parameters remain the same making it easier to identify an appropriate family for this application. Refer to Recommended Logic and Translation Families for Network Switches in this document for help finding the right logic family for your use case.