ADP3404

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 A 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 available 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 processor, charger, and keypad. Furthermore, a reset circuit and a thermal shutdown function have been implemented to support reliable system design.