
REF: BB_SRM_xM BeagleBoard-xM System
Reference Manual
Revision A2
Page 47 of 164
8.3 Power Conditioning
There are two possible sources of the 5V required by the BeagleBoard. It can come from
the USB OTG port connected to a PC or a 5V DC supply. The USB supply is sufficient
to power the BeagleBoard in some cases if the SW does not activate the USB HUB. If the
USB HUB is needed, then a minimum of two PC USB ports are required t supply the
power. However, depending on the load needed by the expansion port on BeagleBoard
and the usage of the USB Host ports, additional power most likely will be required even
in this scenario. This is where the DC supply comes in to play.
It should also be noted that if an OTG configuration is used, for example tying two
BeagleBoards together via a UBS OTG cable, both of the BeagleBoards must be powered
by the DC supply. If the OTG port is used as a Host port, then the DC supply must also
be used.
Figure 21 is the design of the power input section.
5V
P1
mini USB-AB
D-
2
D+
3
VB
1
ID
4
G2
7
G3
6
G1
5
G5
8
G4
9
USB_CLIENT /
OTG PORT
DC_5VP2
CONN_PWR1_2.5MM
2
3
1
R153 32.4K,1%
DC_POWER
U2
TPS2141PWP
LDO_IN
4
LDO_EN
6
SW_IN
2
GND
7
LDO_PLDN
10
LDO_OUT
11
ADJ
9
LDO_PG
8
SW_OUT
12
SW_PLDN
14
SW_PG
1
SW_EN
5
SW_IN
3
SW_OUT
13
PPAD
15
C214
10uF,CER,1206,25V
R152 330
U32
FDC6331L
VIN
4
VOUT2
3
VOUT1
2
R1/C1
6
ON/OFF
5
R2
1
R1_U32
C6
10uF,CER,1206,25V
Figure 21. Input Power Section
Kommentare zu diesen Handbüchern