GSM Power Management System
Handles all GSM Baseband Power Management
Four LDOs Optimized for Speciﬁc GSM Subsystems
Charges Back-Up Capacitor for Real-Time Clock
Charge Pump and Logic Level Translators for 3 V and 5 V
GSM SIM Modules
Narrow Body 4.4 mm 28-Lead TSSOP Package
The ADP3404 is a multifunction power management system IC
optimized for GSM cell phones. The wide input voltage range of
3.0 V to 7.0 V makes the ADP3404 ideal for both single cell
Li-Ion and three cell NiMH designs. The current consumption
of the ADP3404 has been optimized for maximum battery life,
featuring a ground current of only 230 µA when the phone is in
standby (digital LDO, analog LDO, and SIM card supply active).
An undervoltage lockout (UVLO) prevents the startup when
there is not enough energy in the battery. All four integrated
LDOs are optimized to power one of the critical sub-blocks of the
phone. Their novel anyCAP® architecture requires only very
small output capacitors for stability, and the LDOs are insensitive
to the capacitors’ equivalent series resistance (ESR). This makes
them stable with any capacitor, including ceramic (MLCC) types
for space-restricted applications.
A step-up converter is implemented to supply both the SIM
module and the level translation circuitry to adapt logic signals
for 3 V and 5 V SIM modules. Sophisticated controls are avail-
able for power-up during battery charging, keypad interface and
charging of an auxiliary back-up capacitor for the real-time clock.
These allow an easy interface between ADP3404, GSM proces-
sor, charger, and keypad. Furthermore, a reset circuit and a
thermal shutdown function have been implemented to support
reliable system design.
FUNCTIONAL BLOCK DIAGRAM
I/O CLK RST
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