K22-120: Can VDD=1.8V if using USB interface?

[matthew_pattiso]

I am working on a K22-120 design.  I need the USB (device only) interface but also have a bunch of GPIO that needs to be 1.8V.  Can I power the USB via the VREGIN with 5V, but connect the VDD pins to a 1.8V power supply such that all of my GPIO (I2C, SPI, etc..) will be 1.8V.  I am trying to avoid level translators on my gpio for space reasons.

[jingpan]

Hi Matt,

yes, it can. VREGIN should connect to USB VBUS, but VOUT33 connect to ground with a capacitor. Then you can connect VDD to 1.8v.

Regards,

Jing