ADP3405

The ADP3405 is a multifunction power management system IC ptimized for GSM cell phones. The wide input voltage range of .0 V to 7.0 V makes the ADP3405 ideal for both single cell Li-Ion nd three cell NiMH designs. The current consumption of the DP3405 has been optimized for maximum battery life, featuring  ground current of only 150 A when the phone is in standby digital LDO, and SIM card supply active). An undervoltage lockout UVLO) prevents the startup when there is not enough energy n the battery. All four integrated LDOs are optimized to power ne of the critical sub-blocks of the phone. Their novel anyCAP^® rchitecture requires only very small output capacitors for stability, nd the LDOs are insensitive to the capacitors' equivalent series esistance (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 odule and the level translation circuitry to adapt logic signals or 3 V and 5 V SIM modules. Sophisticated controls are available or power-up during battery charging, keypad interface, and harging of an auxiliary backup battery for the real-time clock.These allow an easy interface between ADP₃₄₀₅, GSM processor,charger, and keypad. Furthermore, a reset circuit and a hermal shutdown function have been implemented to support eliable system design.