MAX1745AUB+

The MAX1745AUB+ is an integrated battery-charger and power-management controller for use in portable and/or battery-powered systems. It combines a synchronous buck converter capable of delivering up to 3A of current, a charge-pump boost converter for producing up to 4.4V for systems requiring higher output voltages, and a wide-range boost charger for charging one- or two-cell Li-ion/Li-polymer batteries. Its unique operation mode, wide switching frequency range, and programmable switching-screen regulator allow the MAX1745AUB+ to be used in various system implementations.

Application Field

The MAX1745AUB+ is designed to efficiently power a wide range of products, including digital cameras, cell phones, PDAs, MP3 players, portable navigation devices, and portable media players. The wide input voltage range of the MAX1745AUB+ makes it ideal for these applications, as the device is well-suited to provide a stable, low-noise power source when the user is using a direct-connect AC (DC) adapter or a USB cable. The MAX1745AUB+ has built-in protection features such as thermal shutdown, adjustable overcurrent protection, and adjustable soft-start/reset. The integrated power path feature of the MAX1745AUB+ ensures a timely start-up of the system, and its charge-pump boost converter provides up to 4.4V for systems with higher output voltage requirements.

Working Principle

The MAX1745AUB+ is a complex integrated circuit (IC) for power management and battery charging. It contains a switching regulator, a charge pump, and a wide range boost charger along with numerous other features. The MAX1745AUB+ has two input sources, one from a battery and one from a direct DC source, both of which are managed automatically. The input sources are periodically checked, and the MAX1745AUB+ automatically directs power to the appropriate source. The MAX1745AUB+ automatically regulates the output voltages of both sources to the required system level, providing a stable power supply. The MAX1745AUB+ monitors the system and automatically shuts down when it senses an overcurrent, overvoltage, or overtemperature condition. Additionally, the MAX1745AUB+ features an adjustable soft-start/reset for improved system power sequencing.

The main regulator of the MAX1745AUB+ is based on an advanced synchronous buck regulator, which is capable of delivering up to 3A of current. The charge pump boosts a 1.5V to 4.4V output voltage, and can deliver up to 1.5A of current. The wide-range boost charger can support both single- and dual-cell Li-ion and Li- polymeric batteries. The charger features a low cut-off voltage and fast dynamic response. It can deliver up to 350mA of charging current, and can be configured to deliver either constant current or constant voltage charging.

The MAX1745AUB+ from Maxim Integrated provides flexibility, high efficiency, and robust power management in a small, compact package. Its simple configuration, coupled with its unlimited programmability and high integration potential, makes it an ideal choice for a wide range of portable and/or battery-powered systems.