EVK-M8BZOE User Guide
UBX-17053592 - R03
Early Production Information
Measuring current consumption
Page 21 of 33
6.1.1
ZOE-M8B VCC current
To measure the acquisition and tracking power consumption with the EVK-M8BZOE, follow the below steps. A
picture of the setup can be seen in Figure 9.
1.
Connect a voltmeter to J7 pin 1 and pin 2 to see the voltage over the 1
Ω
current measurement shunt
resistor in the
VCC
supply.
2.
Do a cold reset for the GNSS engine e.g. with u-center software.
3.
Read the voltage (and average for a while if necessary) on the voltmeter and convert to current. 1 mV
equals 1 mA.
o
Average current consumption from power on to first fix will give you the Acquisition current
consumption as mentioned in the
o
After the first fix, the receiver continues to operate in full-power mode. After some minutes when
it has acquired a sufficient number of satellites, it enters the Super-E power save mode. Average
current consumption in this state with a good signal level is less than 10 mA.
Figure 9: Setup to measure the VCC current consumption of ZOE-M8B on EVK-M8BZOE
See Figure 9 as an example where 0.0407 V in average is measured by multimeter over 1
Ω
VCC shunt resistor.
This corresponds (1 mV equals 1 mA) to 40.7 mA average current typical in acquisition phase. In power-optimized
tracking state, the average current consumption can be of the order of 10 mA.
