Gemalto M2M GmbH PHS8-P User Manual

Page of 41
PHS8-P Hardware Interface Overview
3.2 Power Supply
29
PHS8-P_HIO_v01.000
Page 22 of 41
2011-11-10
Confidential / Released
3.2
Power Supply
PHS8-P needs to be connected to a power supply at the SMT application interface - 6 lines 
each BATT+ and GND. There are three separate voltage domains for BATT+:
BATT+_WCDMA with 2 lines for the WCDMA power amplifier supply 
BATT+_GSM with 2 lines for the GSM power amplifier supply 
BATT+ with 2 lines for the general power management. 
The main power supply from an external application has to be a single voltage source and has 
to be expanded to three sub paths (star structure). Capacitors should be placed as close as 
possible to the BATT+ pads. 
 shows two sample circuits (minimum requirement and 
recommended alternative) for decoupling capacitors for BATT+. 
Figure 2:  
Decoupling capacitor(s) for BATT+
The power supply of PHS8-P must be able to provide the peak current during the uplink trans-
mission. 
All key functions for supplying power to the device are handled by the power management IC. 
It provides the following features:
Stabilizes the supply voltages for the baseband using switching regulators and low drop lin-
ear voltage regulators.
Switches the module's power voltages for the power-up and -down procedures.
Delivers, across the VEXT line, a regulated voltage for an external application. This voltage
is not available in Power-down mode and can be reduced via AT command to save power.
SIM switch to provide SIM power supply.
BATT+
BATT+
BATT+_GSM
BATT+_WCDMA
2
2
2
Decoupling capacitor
e.g. 100…220µF
Ultra-low ESR
Module
GND
SMT interface
+
Minimum requirement
BATT+
2
2
2
Decoupling capacitors
e.g. 47µF X5R MLCC
3x
GND
BATT+
BATT+_GSM
BATT+_WCDMA
Module
SMT interface
Recommended alternative