Previous implementations of intelligent battery protection have typically required at least two chips to perform the various tasks required which include: voltage regulation, battery monitoring, battery protection, charge management, and communication with the host application. Often a third chip has been required to store parameters specific to the particular battery. Battery packs must shrink in size along with the other components of battery-powered applications. However, when accelerating this shrink, a 3-chip solution obviously creates a PCB space problem.

The ATmega406 meets all the application’s demands, reducing space, design complexity, and ultimately cost. It includes an AVR® microcontroller with dedicated analog to digital converters tailored for battery fuel gauging and voltage monitoring. Also included are stand-alone high voltage battery protection circuitry, a voltage regulator capable of running the chip on a supply varying from 4 to 25 Volts, integrated cell balancing FETs, and special high voltage I/O capable of controlling charge and discharge. Advanced analog design provides the ATmega406 with unmatched on-chip voltage reference accuracy, resulting in the first single-chip smart battery implementation on the market for 2 – 4 Li-ion cells. With 40 KB of self-programmable Flash program memory, the ATmega406 is capable of in-field firmware upgrades without the need for external programming hardware. Battery parameters can be stored in the internal 2 KB EEPROM. This mix of features makes the ATmega406 AVR capable of implementing a full PC battery pack.