SCLA025B December   2019  – March 2021 SN74LVC1G08

 

  1. 1Trademarks
  2. 2Block Diagram
  3. 3Optimizing Communication with Wireless Interfaces
    1. 3.1 SDIO Voltage Translation
    2. 3.2 UART Voltage Translation
  4. 4Logic and Translation Use Cases
    1. 4.1 Logic Use Cases
      1. 4.1.1 Drive Indicator LEDs
      2. 4.1.2 Power Sequencing: Combine Power Good Signals
      3. 4.1.3 Debounce Switches and Buttons
      4. 4.1.4 Tamper Detection: Latching Alarm Circuit with Reset
    2. 4.2 Voltage Translation Use Cases
      1. 4.2.1 SPI Communication
      2. 4.2.2 SD Card Communication
  5. 5Recommended Logic and Translation Families for HVAC Gateways
    1. 5.1 AUP: Advanced Ultra-Low-Power CMOS Logic and Translation
    2. 5.2 AXC: Advanced eXtremely Low-Voltage CMOS Translation
    3. 5.3 LVC: Low-Voltage CMOS Logic and Translation
  6. 6Revision History

3 Optimizing Communication with Wireless Interfaces

It is common for HVAC gateways to utilize wireless interfaces such as Wi-Fi®, ZigBee®, or Bluetooth® to connect to a local network. In many designs, the simplest method to achieve this is to utilize pre-built and pre-approved modules. These modules often have limited voltage operation ranges, and to support their usage, voltage-level shifters are typically required between the extremely low power processor, often operating as low as 1.2 V, and the wireless module, commonly operating at 3.3 V.

The most common communication protocols used between the processor and wireless interface are secure digital input output (SDIO) and universal asynchronous receiver/transmitter (UART). Each is addressed specifically in the following sections.