`www.thundercomm.com.
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A USB Type C port at 5 V
□The C865 Dev Kit Main IO board supports the 5 V from USB Type C port. It cannot support
system bring up power on.
6.2
Power Source Selection
The 96Boards specification calls for only one power source to be applied to the board at any given
time.
Following this requirement, C865 DEV KIT user should never apply power to the board from #14 (see
Section 1.2.1) and the low-speed expansion connector at the same time.
There is no active or passive mechanism on C865 DEV KIT to prioritize one source over the other.
6.3
Power Sequencing
Upon applying power to the DC12V of the C865 DEV KIT board (from either one of the two sources),
some power will be automatically enable, some will waiting S/W to enable.
4.2V for 865 SOM: will enable after DC12V is asserted. 865 SOM will power on once power-on
button is pressed.
4.2V for IO peripheral: will not enable, S/W can enable it after 865 SOM is powered on.
3.3V/5V for IO peripheral: same as 4.2V for IO peripheral. These 3 power rails are controlled via
one same signal.
6.4
Power Measurements
The 96Boards specification calls for a minimum of one current sense resistor to be placed on the board
permitting basic power measurement functions.
C865 DEV KIT implements two different power measurements.
6.4.1
DC-In measurement
A 0.01ohm resistor R0700 is placed in line of the DC12V on the DC input. Placing a probe over the
resistor pins will provide a voltage measurement of the voltage drop across the resistor. Dividing this
measurement by 0.01 will give you the amount of the current flowing into the DC.
6.4.2
PMIC Power-In measurement (VPH_PWR measurement)
0.01ohm resistors are used on output path of these two 4.2V, 3.3V and 5V for current measurement,
i.e. R0709 for 4.2V of SOM, R0703 for 4.2 V of IO, R0801 for 3.3V of IO and R0805 for 5V of IO.
Placing a probe over the resistor pins will provide a voltage measurement of the voltage drop across
