Hello, I have L6472 with separate power for VSA/B and VDD+VREG (3V3). When VSA/B is powered off IC doesnt respon on SPI. What is propper procedure for power off communication?

[MSlov.1]

In datasheet there is no any connection between VSA and/or VDD. In block schematic are these two voltages separated, also any mention about VSA voltage required to SPI function...

[Cristiana SCARAMEL]

Hello @MSlov.1​ and welcome to the ST Community.

If the VS (VSA = VSB = VS) is not present the device is in reset condition: all logic IO disabled and power bridges in high impedance state.

As reported in the L6472 datasheet (page 20) to have the device operative and so the SPI communication, the following conditions must be satisfied:

• VS greater than VSthOn
• VREG greater than VREGth = 2.8 V (typ.)
• Internal oscillator is operative

Let me know if I solved your doubts, if so please "Select as Best" label.