Kontron SMARC-sA3874i User Manual
Page 28
28
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User’s Guide
Power distribution for external USB plug-in peripherals (USB memory sticks, cameras, keyboards, mice, etc.) is
typically handled by USB power switches such as the Texas Instruments TPS2052B, Micrel MIC2026-1 or similar
devices on the Carrier board. The Enable pin on the Carrier board USB power switch must be active – high and the
Over-Current pin (OC#) must be open drain, active low (these are commonly available). No pull-up is required on
the USB power switch Enable or OC# line; they are tied together on the Carrier and fed to the Module
USBx_EN_OC# pin. The pull-up is on the Module.
Figure 5: USB Power Distribution Implementation on Carrier
U
L
P
-C
O
M
C
A
R
R
IE
R
M
X
M
3
C
O
N
N
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(J
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Enable
USBx_EN_OC#
OC#
USBx_VBUS
Pwr
Switched
Pwr
5V
TPS2052B