General Description
The MAX1612/MAX1613 manage the bridge battery (sometimes called a hot-swap or auxiliary battery) in portable systems such as notebook computers. They feature a step-up DC-DC converter that boosts 2-cell or 3-cell bridge-battery voltages up to the same level as the main battery. This voltage boosting technique reduces the number of cells otherwise required for a 6-cell plus diode-OR bridging scheme, reducing overall size and cost. Another key feature is a trickle-charge timer that minimizes battery damage caused by constant charging and eliminates trickle-charge current drain on the main battery once the bridge battery is topped off.

Features
♦ Reduce Battery Size and Cost
♦ Four Key Circuit Blocks
    Adjustable Boost DC-DC Converter
    NiCd/NiMH Trickle Charger
    Always-On Linear Regulator (+28V Input)
    Low-Battery Detector
♦ Low 18µA Quiescent Current
♦ Selectable Charging/Discharging Rates
♦ Preset Linear-Regulator Voltage
    5V (MAX1612)
    3.3V (MAX1613)
♦ 4V to 28V Main Input Voltage Range
♦ Internal Switch Boost Converter
♦ Small 16-Pin QSOP Package

Applications
    Notebook Computers
    Portable Equipment
    Backup Battery Applications