FEATURES
Handles all GSM Baseband Power Management Functions 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 Thermally Enhanced 6.1 mm 28-Lead TSSOP Package APPLICATIONS
GSM/DCS/PCS Handsets TeleMatic Systems ICO/Iridium Terminals GSM Power Management System ADP3401 FUNCTIONAL BLOCK DIAGRAM VBAT ADP3401 DIGITAL LDO VCC RESET PWRONKEY ROWX POWER-UP SEQUENCING AND PROTECTION LOGIC RTC LDO VRTC PWRONIN ANALOGON RESCAP XTAL OSC LDO VTCXO GENERAL DESCRIPTION
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.