Not using iMX53 USB host - do I need to provide power/components?

[paulmichalczuk]

I am not using the USB Host on my design and noticed that I have several components (caps, inductors, etc) from my previous design. If I am not using this part, do I need the components for that section? I have components on the USB_H1_VBUS, USB_H1_RREFEXT, USB_HI_VDDA25, and USB_H1_VDDA33.

Thank You,

Paul

[jimmychan]

If there is not mentioned specially in the datasheet, generally we have the following unused pin recommendations:

DIGITAL INPUT RECOMMENDATIONS
For unused inputs that are muxed with GPIO :
- Configure pins to be GPIO.
- Configure pins to be inputs.
- Make sure the internal pull up resistors are enabled.

For unused inputs that are not muxed with GPIO pins :
- Connect each pin with a 10K Ohm resistor to ground.

ANALOG INPUT RECOMMENDATIONS
For unused oscillator pins :
- Leave pins floating.
- Make sure that clock is disabled in the clock register.

DIGITAL OR ANALOG OUTPUT RECOMMENDATIONS

- Leave the unused output pins floating

[paulmichalczuk]

Hi jimmychan,

Thank you for the response! All I can find in the datasheet RE: USB Host Controller 1 is that it is not multiplexed with other pins. It does have a 3.3V (USB_H1_VDDA33) and 2.5V (USB_H1_VDDA25) supply - do I treat these as inputs and put a 10K resistor to ground? Right now I have a inductor in series and capacitors in parallel to ground.

Thank You,

Paul

[Yongxin · Accepted solution]

Hi Paul,

Power supplies should be applied to USB_H1_VDDA25 with 2.5V and USB_H1_VDD33 with 3.3V even if modules are not used.

Best Regards,

Yongxin