Integration Manual

Table Of Contents
LISA-U2 series - System Integration Manual
UBX-13001118 - R25 System description Page 17 of 182
1.5 Power management
1.5.1 Power supply circuit overview
LISA-U2 series modules feature a power management concept optimized for the most efficient use
of the supplied power. This is achieved by hardware design that uses a power efficient circuit topology
(Figure 3), and by power management software that controls the module’s power saving mode.
Baseband
Processor
2G/3G
Power Amplifier(s)
Switching
Step-Down
5 x 10 µF
61
VCC
62
VCC
63
VCC
50
VSIM
2
V_BCK
P
4
V_INT
Linear
LDO
Linear
LDO
Switching
Step-Down
Linear
LDO
Linear
LDO
Linear
LDO
I/O
EBU
CORE
Analog
SIM
RTC
NOR
Flash
DDR
SRAM
RF Transceiver
Memory
Power Management Unit
22 µF
220 nF
220 nF
2G/3G PA
PMU
Transceiver
PMU
Figure 3: LISA-U2 series power management simplified block diagram
The pins with supply functions are listed in Table 6, Table 12 and Table 15.
LISA-U2 series modules must be supplied via the VCC pins. There is only one main power supply input,
available on the three VCC pins that must be all connected to the external power supply.
The VCC pins are directly connected to the RF power amplifiers and to the integrated Power
Management Unit (PMU) within the module: all supply voltages needed by the module are generated
from the VCC supply by integrated voltage regulators.