Post Go back to editing

SPI bus with ADUM1401

Category: Hardware
Product Number: ADUM1401


I would like to connect multiple SPI device and to isolate them.

I've used in the past the ADUM1401 isolator, but just for a 1 to 1 isolation.

I'm wondering how to wire it for multiple connection.

Can the schematic attached work?

On the left the microcontroller side, which has SPI ports and one CS pin for each device.
On the right the three devices SPI.

Please note that on the right side the ouput pins are always enabled (i.e. VE2 is always connected to VCC), but the output is read by the device only if proper CS is low.

In the left side the CS cable is inverted. This means that when i would like to talk with one device, I lower the device CS, the VE1 attached to that device should go up due to the NPN inverter.

I'm not sure about this.

Any help will be appreciated.