Did You Know You Can Shift I2C or SPI Logic Signal Levels without a Level Shifter Board?

Question from the Customer:

I am trying to use the Aardvark I2C/SPI Host Adapter or the Cheetah SPI Host Adapter to program an SPI chip that uses 1.8V as the high logic level. Do the Aardvark or Cheetah adapters support various logic signal levels?

Response from Technical Support:

Thanks for your question! We have two solutions for programming a device with a 1.8V logic level:

  • Use the Level Shifter Board with the Aardvark and Cheetah adapters
  • Use the integrated level-shifting feature of the PromiraTM Serial Platform (no accessory boards are required).

The Level Shifter Board

Level Shifter Board Figure 1: Level Shifter Board

Following is a summary of the Level Shifter Board features:

  • Level shifting for I2C, SPI, and MDIO signals
  • Supports voltage levels of 1.2V, 1.5V, 1.8V, 2.5V, 3.0V, and 3.3V
  • Supply power to downstream devices
  • I2C speeds of 800 kHz
  • SPI and MDIO speeds of 20 MHz

The Promira Serial Platform

Promira Serial Platform Figure 2: Promira Serial Platform

The Promira Serial Platform is a robust tool that has the functional flexibility of licensed applications. What are currently available are the SPI Active - Level 1 Application and the I2C Active - Level 1 Application. New, more robust applications will be made available. One of the current features is the level shifting from 0.9V to 5.0V, which applies for both SPI and I2C signals. Following is a summary of the advanced features of the Promira platform:

  • Integrated level shifting from 0.9V to 5.0V
  • USB 2.0 and Ethernet connectivity for faster downloads, remote control, and factory floor automation
  • I2C up to 1 MHz
  • SPI up to 12.5 MHz for master and 8 MHz for slave

Additional resources that you may find helpful include the following:

We hope this answers your question. If you have other questions about our host adapters or other Total Phase products, feel free to email us at sales@totalphase.com, or if you already own one of our devices and have a technical question, please submit a request for technical support.

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