Using SPI with daisy-chained MAX4896 relay drivers

EliazLB · ‎2025-10-15

Hello,

I am working on a home made board featuring an STM32G474QE in 128 pins and multiple relay drivers (MAX4896 : MAX4896 - Space-Saving, 8-Channel Relay/Load Driver)

If I understand it well, the principle is fairly easy, sending a flow of data consisting of 8 times the number of MAX. Once that is done, driving the Chip Select to LOW will drive the outputs of the relay drivers depending on what the value of each bit is.

In my case, I have 9 relay driver daisy-chained so that would be 72 bits to send in one data flow.

I have two questions regarding this. First off all, what mode should I put the SPI in, I coulnd't find this information in the MAX datasheet.

My second question is more of a code issue, would anyone have any example of how to code something of this sort.

Thank you very much for any help

Andrew Neil · ‎2025-10-15

@EliazLB wrote:
what mode should I put the SPI in, I coulnd't find this information in the MAX datasheet.

You should ask Analog Devices that question - it's their chip, not ST's !

https://ez.analog.com/search?engineerzone%5Bquery%5D=MAX4896

https://www.analog.com/en/support.html

A complex system that works is invariably found to have evolved from a simple system that worked.
A complex system designed from scratch never works and cannot be patched up to make it work.