10
ODROID-XU4 USER MANUAL
USB VBUS controller
A NCP380 Protection IC for USB power supply from OnSemi.
Boot media selector
The eMMC/SD card switch on the side of the board selects the
boot media.
Power supply circuit
Discrete DC-DC converters LDOs are used for CPU/DRAM/IO
power supply.
Power protector IC
The power protected is a NCP372 over-voltage, over-current,
reverse-voltage protection IC from OnSemi.
Heat Sink and fan
Electronic components all generate heat while operating, and
Electronic components all generate heat while operating, and different
components generate different levels of heat. Some components do
not require any cooling, while others do.
Complex components such as the XU4 processor may reach
temperatures as high as 95°C. At high temperatures, the processor
will throttle itself and operate slower so that temperatures do not con-
tinue to increase. Some owners prefer that the temperatures do not
reach such high levels and install a heat sink, which is available from
the Hardkernel store. Heat transfer from components to the surround-
ing air is related to the surface area available to transfer heat to the
surrounding air. The processor of the XU4 provides a relatively small
area to dissipate heat. The heat sink is much larger and is therefore
able to dissipate more heat into the surrounding air than the processor
itself.
The fan provides additional cooling by drawing air across the
heat sink, and is controlled through software to vary the amount of
cooling depending on the temperature of the heat sink.
Chapter 1
