EVK-F9T - User guide
UBX-21040453 - R01
GNSS current measurement
Page 12 of 23
C1- Public
5
GNSS current measurement
At start-up, the receiver starts in acquisition state to search for available satellites and to download
GNSS orbital data, i.e., ephemeris and almanac. Once the data has been downloaded, the receiver
enters tracking state. In continuous operation, the receiver typically remains in tracking state once
entering it. The current consumption reduces when the receiver enters the tracking state. The time
required to enter tracking mode can be reduced by downloading aiding data from the AssistNow™
Online service.
To measure the total GNSS supply current with EVK-F9T, follow these steps:
1.
Power up EVK-F9T.
2.
Connect a true RMS voltmeter across CUR GPS1 (pin 12) and CUR GPS2 (pin 13) of the 14-pin
connector.
3.
Read the voltage (and average if necessary) on the voltmeter and convert to current (1 mV equals
1 mA).
4.
Perform the test with good signals and clear sky view to ensure that the receiver can acquire the
satellite signals.
☞
The total GNSS current includes the internal LNA, SPI flash and TCXO.
For more details see the schematic in Figure .
Figure 5: Example
–
tracking current measurement
Hirschmann
Part No.: 934160100
P1A (VCC)
P1B
P1B
P1A (VCC)
