BMD-34x-EVAL User Guide
Rev 2.0
8
Hardware Description
Design files for the BMD-34x-EVAL board may be found on the
Figure 4
–
Assembly Drawing (Top View)
6.1
Power
The BMD-340-EVAL has five possible power sources:
•
USB from the debug interface
•
USB peripheral on the BMD-340 itself
•
CR2032 coin cell battery
•
0.1” through
-hole connector for connecting 3.3V
•
Lithium Polymer (LiPo) battery input.
These power sources use protection diodes to prevent reverse voltage to any supply. This allows them
to be used simultaneously. Solder jumpers are provided to allow by-passing any of the protection
diodes eliminating the voltage drop across them.
Care should be taken to not damage the supplies
when the protection is by-passed.
6.1.1
Powering the Board
During typical debugging, power will be provided by VBUS on the USB debug interface to 5V
to the 3.3V LDO regulator and to the shield connector. The 3.3V LDO regulator will then power VIO,
VSHLD, and VBMD.
When powering the board from the CR2032 coin cell (3VDC), the external power header, or the LiPo
header, USB can be left disconnected. In this configuration, the interface IC is held in reset to conserve