Quote Originally Posted by rsocor01 View Post
mackrackit,

Thank you for guiding me in the right direction. I did some more research and found out that the internal USB regulator must be turned off. The capacitor at Vusb is not needed anymore and the internal USB transceiver and pull-up resistors can be used in the configuration I'm using. I just need to feed 3.3V at Vusb and Vdd.

So, I'm running my PIC18F4550 with Vdd=3.3V and the USB peripheral works! I was able to send and receive data from my computer to the PIC.

As for the GLCD backlight voltage, I have already ordered this chip and the required external components from mouser.com

http://www.onsemi.com/pub_link/Collateral/NCP5007-D.PDF

This chip is a backlight LED boost driver. The input voltage range is from 2.7 to 5.5 Volts, so it should work for my application.

Thank you all again for your help and ideas.

Robert
I think you only read the first line of my post, where I said simple POWER HUNGRY way. You can set a Hardware PWM on your pic and not need that chip you ordered from Mouser, I have used simple 12F chips to do that with pins to spare without using HPWM, so How much easier is using it ? Your money, spend it your way. Cost extra real estate on PCB too.