MAX1538ETI+

The MAX1538ETI+ by Analog Devices is a specialized integrated circuit designed for power-source control in dual-battery systems. It intelligently selects between an AC adapter and two batteries based on their presence and charge state. This device simplifies power management by independently monitoring and selecting power sources, freeing up the system's microprocessor.

Key features include automatic detection of low-battery voltage conditions, battery insertion/removal, and AC/airline adapter presence. It supports step-down and step-up charger compatibility and offers fast break-before-make selection for hot-swapping power sources without external Schottky diodes. The MAX1538ETI+ operates with an AC-adapter input voltage range of 4.75V to 28V and has a maximum battery quiescent current of 50µA.

This power-source selector is suitable for applications such as notebook and subnotebook computers, internet tablets, and other dual-battery portable equipment. It is available in a compact 28-pin Thin QFN package with a 5mm x 5mm footprint, facilitating space-saving designs. The device also supports a 'relearn mode' for measuring battery capacity and can be used to power systems directly from an aircraft supply.

The MAX1538ETI+ simplifies power-management firmware development and allows the microprocessor to enter standby mode, reducing overall system power consumption. It directly drives P-channel MOSFETs and is designed for reliable operation within an extended temperature range.