Cinterion
®
LGA DevKit Things User Guide
4.11 Power Supply
25
t
lga_devkit_t_ug_v01
2020-08-20
Public / Released
Page 15 of 26
4.11
Power Supply
The LGA DevKit can be supplied through one or two USB ports that should be in the range of
5V +-5%, and/or externally by the DSB75/DSB-Mini. The modules supply level can be adjusted
in the range between 2.8…4.8V by setting the variable resistor at the DevKit's top side. The
DevKit power supply path is short protected with ~2A. In case of overcurrent the power path
will be interrupted and the red LED lights up until the power has been reset.
As a recommendation the LGA DevKit should be supplied with 5V/1A over one or two USB
ports. The onboard bypass capacitors should buffer enough energy to support short 2G peak
currents up to 2.5A.
4.11.1
Supply Current Measurement
The LGA DevKit supports three methods to measure the current consumption of the inserted
module.
•
Measure the voltage across the on board 100 mOhm shunt resistor
•
Measure the current by a current meter
•
Power the module by an external power supply e.g. power analyzer
All options require a jumper placed on the 4
th
"BB" and 5
th
"RF" row for connecting baseband
and radio. Those two jumpers also allow to measure the current separately for the BB and RF
path.
Figure 11:
Supply current measurements
Note:
When measuring with a current meter, the meter’s internal resistance may cause a high
voltage drop, forcing the module to shut down. This can be avoided by measuring the voltage
cross the shunt. The current option is suitable for specialist power meter supplies, whereas the
voltage option is suitable for common voltage meters.
