A few doubts about PCB layout and first project

[luisonoff]

[SOLVED] A few doubts about PCB layout and first project

Hello,
I am designing a 2 layer PCB to plug a Teensy 3.1 on it, my bottom layer is GND.
My questions:

- Is it fine if I connect AGND directly to GND? Or better leave AGND unconnected? (Te only analog thing I have is a voltage divisor connected to battery and GND).

- Any trouble if I leave PROGRAM, RESET and VBAT pins unconnected?

- Should I connect all 3.3V pins to my power supply or just connect one and leave others unconnected? Does it matter which one? (I am powering from 3.3V powersupply directly to 3.3V pin.)


Thank you very much for your help!

 

[PaulStoffregen]

Before you complete your PCB design, I would highly recommend prototyping and testing your connections on a solderless breadboard. Discovering and fixing design mistakes is much faster and easier when you can simply plug the wires into the breadboard.

- Is it fine if I connect AGND directly to GND? Or better leave AGND unconnected?

If you're not using AGND, simply leave it unconnected. GND is the one that really matters.

- Any trouble if I leave PROGRAM, RESET and VBAT pins unconnected?

All of these can be left unconnected, if you're not using them.

- Should I connect all 3.3V pins to my power supply or just connect one and leave others unconnected? Does it matter which one? (I am powering from 3.3V powersupply directly to 3.3V pin.)

Best to connect both GND pins together, and both 3.3V pins together on your design.

But if you use only 1 pair (eg, if you're using a 28 pin socket), it's ok to leave the others on the right side of the Teensy unconnected. Connecting both is better, but not absolutely necessary.

 

[luisonoff]

Thank you very much for your answer Paul.
I will test everything in a breadboard before sending the PCB to manufacturer.

 

[stevech]

Some here may also help by reviewing the schematic and artwork, if this is a non-professional project!