■ 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