Cinterion
®
ELS31-VA/ELS51-VA Hardware Interface Description
3.4 Power Supply
76
ELS31-VA_ELS51-VA_HID_v01.000
2017-01-04
Confidential / Preliminary
Page 68 of 106
3.4
Power Supply
ELS31-VA/ELS51-VA needs to be connected to a power supply at the SMT application inter-
face - 2 BATT lines and GND. There are two separate voltage domains for BATT:
•
BATT_BB with a line mainly for the baseband power supply.
•
BATT_RF with a line for the RF power amplifier supply.
Please note that throughout the document BATT refers to both voltage domains and power
supply lines - BATT_BB and BATT_RF.
The power supply of ELS31-VA/ELS51-VA has to be a single voltage source at BATT_BB and
BATT_RF. It must be able to provide the current for all operation modes of the module.
All the key functions for supplying power to the device are handled by the power management
section of the analog controller. This IC provides the following features:
•
Stabilizes
the supply voltages for the baseband using low drop linear voltage regulators and
a DC-DC step down switching regulator.
•
Switches the module's power voltages for the power-up and -down procedures.
•
SIM switch to provide SIM power supply.