a
GSM Power Management System
ADP3401
FEATURES
FUNCTIONAL BLOCK DIAGRAM
Handles all GSM Baseband Power Management
Functions
VBAT
Four LDOs Optimized for Specific GSM Subsystems
Charges Li-Mn Coin Cell for Real-Time Clock
Charge Pump and Logic Level Translators for 3 V and 5 V
GSM SIM Modules
ADP3401
DIGITAL
VCC
LDO
Thermally Enhanced 6.1 mm 28-Lead TSSOP Package
RESET
APPLICATIONS
PWRONKEY
GSM/DCS/PCS Handsets
TeleMatic Systems
ICO/Iridium Terminals
RTC LDO
VRTC
ROWX
POWER-UP
SEQUENCING
AND
PROTECTION
LOGIC
XTAL OSC
LDO
PWRONIN
ANALOGON
RESCAP
VTCXO
VCCA
GENERAL DESCRIPTION
ANALOG
LDO
CHRON
The ADP3401 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 ADP3401 ideal for both single cell Li-Ion
and three cell NiMH designs. The current consumption of the
ADP3401 has been optimized for maximum battery life, featuring
a ground current of only 150 µA when the phone is in standby
(digital LDO, and SIM card supply active). An undervoltage lock-
out (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.
SIMBAT
CAP+
CAP؊
CHARGE
PUMP
VSIM
SIMPROG
SIMON
BUFFER
REFOUT
DGND
REF
SIMGND
+
RESETIN
CLKIN
LOGIC LEVEL
TRANSLATION
AGND
DATAIO
CLK RST
I/O
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 backup battery for the real-time clock.
These allow an easy interface between ADP3401, GSM proces-
sor, charger, and keypad. The 28-lead TSSOP package has been
thermally enhanced to maximize power dissipation capability.
Furthermore, a reset circuit and a thermal shutdown function
have been implemented to support reliable system design.
anyCAP is a trademark of Analog Devices, Inc.
REV. 0
Information furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assumed by Analog Devices for its
use, nor for any infringements of patents or other rights of third parties
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.
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Tel: 781/329-4700
Fax: 781/326-8703
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© Analog Devices, Inc., 2000