LEON-G100 / LEON-G200 - System Integration Manual
GSM.G1-HW-09002-G3
Preliminary
System description
Page 15 of 125
1.5
Power management
1.5.1
Power supply circuit overview
V_BCKP
GSM/GPRS Chipset
PSRAM
NOR Flash
MCP Memory
4-Bands GSM FEM
Antenna
Switch
PA
LDOs
BB
LDOs
RF
RTC
LDO
LDO
EBU
Charging Control
1 µF
1 µF
LDO
VSIM
VCC
LEON-G100 /
LEON-G200
2 x 22 µF
2
35
50
Figure 3: Power supply concept
Power supply is via
VCC
pin. This is the only main power supply pin.
VCC
pin connects the RF Power Amplifier and the integrated power management unit within the module: all
supply voltages needed by the module are generated from the
VCC
supply by integrated voltage regulators.
V_BCKP
is the Real Time Clock (RTC) supply. When the
VCC
voltage is within the specified extended operating
range, the module supplies the RTC: 2.0 V typical are generated by the module on the
V_BCKP
pin. If the
VCC
voltage is under the minimum specified extended limit, the RTC can be externally supplied via
V_BCKP
pin.
When a 1.8 V or a 3 V SIM card type is connected, LEON-G100/LEON-G200 automatically supply the SIM card
via
VSIM
pin. Activation and deactivation of the SIM interface with automatic voltage switch from 1.8 to 3 V is
implemented, in accordance to the ISO-IEC 78-16-e specifications.
The integrated power management unit also provides the control state machine for system start up, including
start up with discharged batteries, pre-charging and system reset control.
LEON-G100/LEON-G200 feature a power management concept optimized for most efficient use of battery
power. This is achieved by hardware design utilizing power efficient circuit topology, and by power management
software controlling the power saving configuration of the module. Battery management runs in the context of
the operation and maintenance process:
Battery charging control, in order to maintain the full capacity of the battery
Collecting and processing of measurements of battery voltage