LN920 HW Design Guide
1VV0301730 Rev. 1
Page 30 of 81
2021-08-11
Not Subject to NDA
Mode
Measure
(Typical)
Mode
Description
WCDMA
LTE
Table 17: LN920 Connected Mode Current consumption
General Design Rules
The main guidelines for the Power Supply Design include three different design steps:
•
Electrical design of the power supply
•
Thermal design
•
PCB layout
4.3.1.
Electrical Design Guidelines
The electrical design of the power supply strongly depends on the power source where
this power is drained. We will distinguish them into three categories:
•
+5V input (typically PC internal regulator output)
•
+12V input (typically automotive)
•
Battery
4.3.1.1.
+5V Source Power Supply Design Guidelines
•
The desired output for the power supply is 3.3V, so the difference between the
input and the desired output voltage is limited and a linear regulator can be used.
A switching power supply will not be suitable for this application, due to the low
drop out requirements.
