User manual

LPCXpresso Prototype Board - User’s Guide

Page 10

3.3 Board Powering

The LPCXpresso Prototype Board distributes voltages according to Figure 6. The red rectangles

illustrate the holes where GND-potential is available. All the areas are connected. The green

rectangles illustrate where +3.3V-potential is available. All the areas are connected. The pcb silk

screen also indicates where GND and +3.3V is available.

Figure 6 – Board Powering

Note that the “+3.3V” potential is about +3.3V, but slightly lower due to voltage drop from a back-feed

protection diode on the LPCXpresso Board if the +3.3V is generated on the LPCXpresso Board.

These are the powering options for LPCXpresso:

 The +3.3V can be generated from the LPCXpresso Board.

o Power can come from a PC via the USB-interface for LPC-LINK.

o Power can alternatively come from an external +5V source (that connects to VIN on

the LPCXpresso Board).

 The +3.3V can come from an external source. Note that this power source must be able to

handle that the LPCXpresso Board also can power the +3.3V.

These are the powering options for mbed:

 The +3.3V can be generated from the mbed module.

o Power can come from a PC via the USB-interface on the module.

 Power can alternatively come from an external +5V source (that connects to VIN on the

module).