L6470 When CS goes low pulls SDI down with it?

Posted on July 05, 2016 at 11:11

Hi,

I have been using an microchip explorer16 board with the EVAL6470H board and working fine. Swapped over to my design PCB and there is a peculiar fault where when the CS pin is high the SDI at the L6470 works normally switching 0-3V3, however as soon as the CS pin goes low this pulls down the SDI signal to 0-0.5V. I lifted the SDI pin and the signal returns to 3V3, so I assumed that I had overheated the chip soldering it to the board and replaced with another new IC. But the fault is still there, my code is stripped right back to just setting the CS & SDI pins high and low and I can't think what it would be any ideas please?

Thanks

#l6470-cs-sdi-spi-problems