■ DESCRIPTION

MB3891 is intended to be used in future GSM-phones, Dual Band phones and Dual Mode phones. It contains all the necessary functions to support all Digital, Analog and RF blocks in these phones. A Charge-pump including a Logic Level Translation circuit is built in to support SIM-card (SmartCard) of both 3 and 5 Volt technology. The circuit contains a charger for a rechargeable Lithium coin cell of a Real Time Clock.

A complex control circuit is built in to generate main reset and to turn on and off the different LDO’s.

■ FEATURES

• Supply voltage range : 3 V to 5.5 V

• Low power consumption current during standby : 400 µA (MAX)

• 6-channel low-saturation voltage type series regulator

: 2.1 V/2 channels, 2.8 V/3 channels, 2.5 V/2.8 V switch

• Error prevention function during Low voltage

• Power on reset function

• 3 V/5 V SW for SIM-Card

• SIM interface function

• Backflow prevention function for Battery-Backup

• Temperature prevention function