User's Manual

Table Of Contents
ABOUT THE DEVELOPMENT BOARD
Current Measurement Option (CMO)
56 ConnectCore 9c/Wi-9C Hardware Reference, Rev. B 01/2007
3
How the CMO
works
This drawing shows how the Current Measurement Option works.
To measure the load current used on different power supplies, measure DC voltage
across the sense (CMO) resistor. The value of the resistor is 0.025
R ± 1%. Calculate
the current using this equation:
I = E/R
where
I = current in Amps
E = measured voltage in Volts
R = 0.025 Ohms
Current
measurement
option, CMO
R69
R78
Power
connector
+9VDC -
+30VDC
Current
Measurement
Option
Current
Measurement
Option
R69
0.025R
R78
0.025
R
+5VDC
+3,3VDC
+5V
power
controller
+3.3V
power
controller