Atmel Corp. (San Jose, CA) announced its new ATmega406 high-voltage AVR® microcontroller (MCU), which implements full two-cell to four-cell lithium-ion (Li-Ion) smart battery monitoring and protection on a single chip. To enable the ATmega406 to be powered directly from a two-cell, three-cell or four-cell Li-Ion configuration, the device includes an on-chip voltage regulator allowing the device to be powered from 4 V to 25 V. It also features three 25 V-tolerant FET drivers for charge, discharge and pre-charge, as well as on-chip FETs for cell balancing.
To provide an accurate estimate of charge left, the device has a Coulomb Counter ADC with an 18-bit output for battery current monitoring, as well as a 12-bit ADC for individual cell voltage and temperature monitoring. Both ADCs use high-accuracy on-chip voltage reference. Battery protection is autonomous, providing the end-user with the best safety, as MCU-related issues such as a code runaway or a software bug do not affect it.
All parts of the ATmega406 are optimized for low power consumption, drawing less than 1.2 mA in active mode and less than 2 µA in power-off mode. The ATmega406 is available in the LQFP 48-pin package, and pricing starts at $2.75 for volumes above 100,000.