TMAG5170: Can I use multiple TMAG5170A2 sensors in one power source?

Minuk,

To build an array of this size, you would very likely need to use expanders on the SPI bus and careful routing to ensure that the SPI bus remains clean, but it could certainly be done with careful planning.  The ALERT pin as an interrupt would be another challenge to consider.  This pin is open drain, so a pull-up is required.  If all sensors were connected to the same net, then placement of a pull-up resistor would be somewhat challenging.  What might be easier is to combine them using logic gates.  For example, several devices might be input to an NAND gate.  If any of them were to trigger an ALERT condition and be pulled low, the output state of the NAND would change from 0 to 1.  The output of the NAND gates could be combined through OR logic to determine if any of the devices produced an ALERT condition.

If ALERT is used as a trigger, there are two options.  If you are interested in triggering all devices simultaneously to capture a consistent state at any time then it would need to be shared across devices.  It may be beneficial to add periodic buffers to keep the signal clean.  The other option would be to route ALERT with the SPI mux so that individual devices may be triggered selectively.

Some more ideas and details are available in this application note:

https://www.ti.com/lit/ab/slya070a/slya070a.pdf

Thanks,

Scott