Question from the Customer:
I understand the Cheetah SPI Host Adapter comes with the option of using either an external power supply or the Cheetah adapter (with power from the USB bus I assume) to drive the SPI output.
My question is about ground - if I am using an external power supply to drive the SPI device output, is the ground from the external power supply electrically isolated from the USB ground on the other end of the Cheetah adapter?
I also have questions about connecting power.
Thanks for your questions! The following sections provide the information that you requested.
The USB and SPI sides on Cheetah adapter are not galvanically isolated as they share a common ground. For the best results, we recommend tying the ground pins of the target system to the Cheetah adapter ground pins.
Pins 4 and 6 are output pins – they provide power with the voltage level of 5V to target boards or chips.
For more information about the pins and related signals, please refer to the Connector Specification of the Cheetah SPI Host Adapter User Manual.
The component, DN401 is an ESD protection diode for SS1/SS2 lines. The DN401 can be replaced with a new NSQA6V8AW5T2G part from ON Semiconductor.
For more information about power consumption and related specifications, please refer to the section Signal Specifications / Power Consumption of the Cheetah SPI Host Adapter User Manual.
Additional resources that you may find helpful include the following:
More questions? More projects? You can contact us at sales@totalphase.com. You can also request a demo that applies to your application.