Robotics RB5 Development Kit Hardware User Manual
Copyright© 2020 Thundercomm Technology Co., Ltd. All rights reserved.
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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.
RB5 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)
A 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 the resistor. Dividing this measurement by 0.01 will give you the amount of
the current.
