Support Question of the Week: Control Target Power from an SPI Host Adapter to a Target Device

I am programming memory chips and I am providing power to the target device from a separate power supply. I will not be using USB power because the memory chips use 3.3V. I have a voltage regulator installed before the chip power pins, which seems to interfere with using the Cheetah SPI Host Adapter.

My question - do I need to isolate Cheetah adapter pins 4 and 6 from the power source?  If there's another way to do this, please tell me how.

Thanks for your question! You do not need to physically isolate Cheetah SPI Host Adapter pins 4 and 6 from your target devices. You have the option of powering the target device with the Cheetah SPI Host Adapter or an external power source.  You can disable or enable power from the Cheetah SPI Host Adapter with our software tools - Cheetah GUI Software, Flash Center Software or Cheetah Software API.

With Flash Center Software, you can set target power on or off (see Figure 1). For more information, please refer to section 3.2.3 of the Flash Center Software User Guide.

Using Flash Center to Control Target power from a Cheetah SPI Host Adapter Figure 1: Flash Center Software Host Adapter Panel

You can also control target power using Cheetah GUI Software (see Figure 2).  For more information, please refer to section 3.2.7 of the Cheetah GUI Software User Guide.

Using Cheetah GUI to control target power from a Cheetah SPI Host Adapter Figure 2: Cheetah GUI Software Control Panel

API software examples are available, which you can download and then modify as you wish. For information about using API software, please refer to chapter 5 of the Cheetah Host Adapter User Manual.

We also provide Level Shifter boards, which can used to interface our Host Adapters and Protocol Analyzers to target devices with the selected voltage level of 1.2V, 1.5V, 1.8V, 2.5V, 3.0V or 3.3V.

For more information about the Cheetah SPI Host Adapter, support software and other tools, please refer to the following:

Flash Center User Guide
Cheetah GUI Software User Guide
Cheetah SPI Host Adapter
Cheetah Host Adapter User Manual
Level Shifter Boards
Total Phase Products

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 or

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